International conference on Frontiers in Chemical Technology 2020 (FCT 2020)

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Antibacterial activities of peptaibols, trichocellin A-I and B-II, isolated from the endophytic fungus Trichoderma reesei
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Madhushika, D. P. H.; Jayasundara, J. M. N. M.; Ratnaweera, P. B.; Williams, D. E.; de Silva, E. D.; Andersen, R. J.
Antibiotics are highly used in chemotherapy for bacterial infections worldwide. However, due to misuse and overuse of antibiotics pathogenic bacteria have developed and continue to develop resistance to the existing antibiotics rendering them ineffective. Thus there is an urgent need to develop new types of antibiotics to counter the spread of these lethal, drug resistant infections. Endophytic fungi of Cyperaceae plants are a relatively unexplored but a significant resource for the discovery of new biologically active natural products. Therefore, the main objective of this study was to isolate bioactive secondary metabolites of the endophytic Trichoderma reesei (GenBank accession number MT476871) fungus isolated from Cyperus iria in Sri Lanka. Initial screening of T. reesei showed antibacterial activity against the Gram positive Bacillus cereus and Staphylococcus aureus at 400 μg/mL. T. reesei was grown in large scale and extracted into ethyl acetate following an incubation period of 13 days. Solvent-solvent partitioning of the crude extract (1005 mg) led to an active chloroform fraction (580 mg), which was chromatographed on Sephadex LH20 size exclusion column chromatography. The active fraction B (143 mg) from the six fractions (A-F) obtained from size exclusion chromatography was further purified via C18 reversed-phase high performance liquid chromatography (HPLC) to yield two peptaibols. The structures of the peptaibols were determined as trichocellin A-I and B-II by nuclear magnetic resonance (NMR) and mass spectral data. Both peptaibols A-I and B-II were active against the two Gram positive bacteria tested with minimum inhibitory concentrations (MICs) of 64 and 8 μg/mL for B. cereus and 32 and 16 μg/mL for S. aureus respectively. The positive control Gentamycin gave a MIC of 2 μg/mL for both bacteria. To the best of our knowledge this is the first study to isolate trichocellins from an endophytic T. reesei fungus. The study revealed that the isolated trichocellins from T. reesei are potent antibacterial compounds.
Antibacterial activity of entomopathogenic fungi isolated from Vespa affinis and Apis dorsata in Sri Lanka
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Sandeepani, H. P.; Ratnaweera, P. B.
Antibiotic resistance of bacteria throughout the world has caused serious health issues. Thus, there is a crucial need for the discovery and development of new antibiotics. Entomopathogenic fungi infect and eventually kill their host insects. However, entomopathogenic fungi are known to be a rich source of bioactive secondary metabolites. The main aim of the current study was to isolate and investigate the antibacterial activities of entomopathogenic fungi of two insect species Apis dorsata and Vespa affinis collected from Uva Wellassa University library premises, Badulla, Sri Lanka (810 4’ E, 60 58’N). Freshly dead insect cadavers were collected, surface sterilized, crushed and spread on antibiotic (Amoxicillin, 10 mg/mL) enriched potato dextrose agar media plates. The emerging fungi were isolated, pure cultures were obtained and extracted into ethyl acetate. The fungal crude extracts were tested for antibacterial activity against Staphylococcus aureus (ATCC 25928), Bacillus cereus (ATCC 11718), Escherichia coli (ATCC 35218) and Pseudomonas aeruginosa (ATCC 9027) using agar disc diffusion method (400 μg/disc) and bioautography. The experiments were carried out in triplicate. For the identification of fungi, genomic DNA were isolated, the ITS region of the ribosomal RNA gene was amplified using ITS1 and ITS4 primers, the obtained PCR products were sequenced and BLAST analyzed. Nine morphologically different entomopathogenic fungal strains were isolated from A. dorsata while eight were isolated from V. affinis. Thirteen fungal extracts showed antibacterial activity against at least one bacterial species tested while four extracts were inactive to all bacteria. Ten, eight and nine fungal extracts showed some activity against S. aureus, B. cereus and E. coli respectively while none of the extracts showed any activity against P. aeruginosa. Talaromyces versatilis fungal extract from A. dorsata showed the best inhibition with a mean diameter of 13.00 ± 1.00 mm against E. coli with an activity similar to the positive control (Gentamycin, 1000 ppm). The bioautography assays revealed that T. versatilis and an Aspergillus extracts were active against S. aureus while A. nomius extract was active against B. cereus. The FTIR analysis and thin layer chromatography studies exhibited the presence of many secondary metabolites in all fungal crude extracts. This study shows that entomopathogenic fungi of V. affinis and A. dorsata are potential sources for the discovery of novel antibacterial drug leads.
Antibacterial cytochalasin B from endophytic Curvularia lunata isolated from Cyperus iria of Sri Lanka
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Kumarasinghe, K. H. T. P.; Pavalakantharasa, T.; Jayasundara, J. M. N. M.; Ratnaweera, P. B.
Antibiotic resistivity of bacteria has been increasing rapidly over the last few decades and currently it has become a severe human health crisis in the world. Therefore, isolating novel antibacterial drug leads from natural sources has become an essential requirement in today’s world. Thus, the main aim of the current study was to isolate the antibacterial compounds from the endophytic fungus Curvularia lunata isolated from an underutilized plant Cyperus iria of Sri Lanka. During a preliminary research C. lunata fungal extract showed antibacterial activity against Gram positive Staphylococcus aureus and Bacillus cereus. Hence the fungus was grown in large scale in 140 Petri dishes and was extracted to ethyl acetate after 21 days of incubation. The ethyl acetate crude extract (354 mg) obtained was purified using bioassay guided fractionations using a series of solvent/ solvent fractionations, Sephadex LH20 size exclusion chromatography using methanol as the eluent, normal phase silica gel chromatography using a gradient elusion and finally by reversed phase high performance liquid chromatography to isolate the major bioactive compound. The structure elucidation using 1H, 13C and 2D (COSY, HSQC, HMBC) nuclear magnetic resonance (NMR) and mass spectroscopic data revealed the identity of the major bioactive compound as cytochalasin B (1). Cytochalasin B showed prominent antibacterial activity with a minimum inhibitory concentration (MIC) of 64 μg/mL against S. aureus while the positive control Gentamycin showed a MIC of 4 μg/ mL. Further purification of other bioactive fractions with interesting 1H NMR spectra may to lead to novel antibacterial compounds. This study reveals that endophytic C. lunata of C. iria are potential producers of antibacterial compounds.
Antioxidant, anti-inflammatory and antibacterial potentials of aqueous leaf extract of Pouteria campechiana (Kunth) Baehni (Ratalawulu)
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Hettiarachchi, O. I.; Deraniyagala, S. A.; Hettiarachchi, C. M.
Antioxidants are of dietary importance in preventing oxidative stress due to the production of excess free radicals in our body leading to many diseases including cancer, atherosclerosis and diabetes as well in aging. Despite the advances in modern medicine, plant -based remedies play an important role in healthcare due to less side effects. Due to the side effects of NSAIDS and antibiotics, plant -based remedies would be beneficial. This study was conducted to assess the potential use of P. campechiana (Ratalawulu) as an antioxidant, anti-inflammatory and antibacterial agent. The aqueous leaf extract of Ratalawulu was prepared according to the method of decoction preparation in ayurvedic medicine. All assays were carried out according to previously published procedures. Aqueous leaf extract of P. Baehni showed a Total Phenolic Content of 230.71±7.62 mg (PGE)/g in the Folin-Ciocalteu method. Total flavonoid content was 140.98 ± 98.46 mg (QE)/g according to AlCl3 colorimetric assay [PGE- Pyrogallol equivalence, QE- Quercetin equivalence]. 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity of aqueous leaf extract of P. Baehni ranged between 1.4%-17.8% for concentration between 0.01-0.1 mg/ml whereas ascorbic acid showed 2.46%-43.93% for the same concentration range. Ferric ion reducing assay for aqueous leaf extract of P. Baehni showed gradual increase in reducing property relating to antioxidant action by donating a hydrogen atom to break free radical chains. Hydroxyl scavenging activity showed 5.73%-44.03% for concentration series of 20-100 mg/ ml whereas, Ascorbic acid ranged from 9.40%-47.06%. Hydroxyl radical is one of the potent reactive oxygen species in the biological system. Nitric oxide scavenging anti-inflammatory assay showed 58.06%-75.36% whereas ascorbic acid showed 80.73%-91.76% for concentration series of 0.4-6.4 mg/ ml. In the human red blood cell assay, percentage protection by aqueous leaf extract of P. Baehni was 15.0%-62.4% and that of ascorbic acid was 12.1%-72.8% for 6.0-300 μg/ml. Aqueous leaf extract of P. Baehni also showed antibacterial activity against Staphylococcus aureus. Taken together, these results suggest the potential use of aqueous leaf extract of P. Baehni as an antioxidant, anti-inflammatory and antibacterial agent, and merit further related investigation.
Association between high sensitivity C-reactive protein and body compositions among community dwelling healthy adults; a cross-sectional study among South East Asians
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Silva, Eranga Harshani; Wickramatilake, Chandima Madhu; Lekamwasam, Sarath; Mudduwa, L. K. V.; Ubayasiri, Ranjuka Arushana
High sensitivity C-reactive protein (Hs-CRP) is a predictor of future vascular events. Although studies have shown that Hs-CRP is linked with body fat content, data among South East Asians are inconsistent and sparse. Objective of this study was to determine the association between Hs- CRP and body composition indices among community dwelling healthy adults. Seventy (women=9) healthy adults, free of medications and excessive use of alcohol (more than one unit of alcohol per day) and smoking (more than one cigarette per day) were recruited as community controls of an ongoing study. Hs-CRP was measured by an ELISA method on fasting state and they underwent Dual-energy X-ray absorptiometry (DEXA) to measure body compositions (total body fat mass (TBFM), truncal fat mass (TRFM), total body lean mass (TBLM), total body bone mineral content (TBBMC), total body bone mineral density (TBBMD)). Mean (SD) age of the group was 47(9) years with a mean (SD) body mass index of 23.4(3.6) kgm-2. Median (IQR) Hs-CRP was 0.8 (0.4-1.9) mg/L. A significant positive correlation (Spearman rho) was observed between Hs-CRP and TBFM (r=0.52) TRFM (r=0.54) and fat percentage (r=0.55) (p<0.001 for all). No significant correlations were observed between Hs-CRP and TBLM or TBBMC/TBBMD. Among healthy adults’ Hs-CRP is linked with both total and truncal fat masses and not with lean or bone masses. This information supports the view that chronic inflammation is linked with body fat content than other body compartments.
Bioaccumulation of nephrotoxic metals in rice grains (Oryza sativa) in a CKDu hotspot in Sri Lanka via soil analysis
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Dayananda, M. D. N. R.; Liyanage, Janitha A.
Accumulation of nephrotoxic metals in edible crops and associated soil is a major international concerns today which results food safety issues and adverse health risks like CKDu. Soils are considered to be an excellent media to monitor and assess chemical pollution where the application, deposition and absorption of chemicals are taken place. Therefore, this study attempts to investigate the bioaccumulation of nephrotoxic metals in soil and rice grains (Oryza sativa) and to interpolate the spatial distribution of selected chemical elements using Inverse Distance Weighted (IDW) and Spatial Autocorrelation tools in ArcMap 10.2.2 software in a CKDu hotspot; Girandurukotte Grama Niladhari Division (GND), Badulla, Sri Lanka via soil analysis. Dambethalawa GND in Ampara district was selected as the reference site. 30 soil samples were collected according to random stratified design including 10 paddy cultivated sites and 10 composite rice grain samples were collected from those paddy fields separately. Microwave digested soil and rice samples were analyzed by inductively coupled plasma mass spectrophotometry. The average concentrations of Cd, Pb, As, Cr, Ca and Mg in soil were 0.45±0.02, 0.20±0.02, 0.65±0.25, 0.29±0.04, 4812.00±692.00, and 15157.00±1275 mg/kg respectively. According to the lower Moran’s indices given by the Spatial Autocorrelation, the selected metals were evenly distributed throughout the sampling area and Cd, Pb, Ca and Mg contents in CKDu prevailed area was significantly higher (p<0.05) than the reference. The higher bioaccumulation factors (from soil to rice grain) (BCF>1) indicated that rice grains tend to accumulate the nephrotoxic metals including Cd;2.35, Pb;7.48, As;2.60 and Cr;5.80. The calculated Enrichment factors (EF) which derives the degree of soil contamination by nephrotoxic metals were Cd;6.49, Pb;6.01, As;1.30 and Cr;1.48 and greater EFs (EF>1) indicates higher availability and distribution of metals in contaminated soil when compared to the reference. It can be concluded that the degree of soil contamination by nephrotoxic metals was higher in the selected CKDu hotspot than the reference. Hence, human renal dysfunctions can be related with consumption of contaminated rice with those metals.
Chemical characterization of endolichenic fungi, Talaromyces pinophilus residing in the lichen, Arthonia sp. collected from mangroves of Sri Lanka
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Shevkar, C.; Armarkar, A.; Maduranga, K.; Weerasinghe, R.; Pandey, K.; Kalia, K.; Paranagama, P. A.; Kate, A.
Lichens are one of the interesting symbiotic organisms comprising of algae, fungi and other microbiota. The complex miniature ecosystem of lichen provides a competitive environment to endolichenic fungi, which makes it suitable for the production of structurally diverse molecules. Mangroves of Sri Lanka are well-known for the presence of various type of lichens and hence, in this study, 32 specimens of lichen were collected from mangroves of Puttalam Lagoon of Sri Lanka. LCMS based dereplication study was carried out for the isolated 70 cultures of endolichenic fungi from lichens. Talaromin B and Ergochrome BB were present in the ethyl acetate extract of Talaromyces pinophilus along with probable novel compounds having m/z [M+H]+ 663.2321, 778.4128, 401.3029 with “no hit” in Dictionary of Natural Products (DNP). The mentioned extract showed promising anti-cancer activity having IC50 of 50.32 μg/mL tested against MCF-7 cell line (Human breast cancer cell line) by Alamar blue assay. The extract was then scaled up for further isolation of masses showing no hits in DNP. Here, 2 known and 2 new compounds were isolated with 95-98% purity from the scaled up fermentation batch including [NIPER20099_83_7/30_1] Peniazaphilin B and a macrocyclicpolyester [NIPER20099_83_7/30_2] (15G25α). Structural elucidation of two novel molecules is in process. All four molecules were tested in vitro against MCF-7 cell line and only one molecule [NIPER20099_83_7/30_3] having molecular weight 560.2045 showed promising activity with the IC50 value of 22.15μM. The study suggest Talaromyces pinophilus might serve as a source of novel cytotoxic hit. Investigating secondary metabolites of the endolichenic fungi might help us to unravel the complex ecosystems of lichen and help us understand its further therapeutic benefits.
Comparison study of the oxalate content in commonly used green leafy vegetables
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Liyanage, J. V.; Jayasundara, U. K.
Consumption of large amount of oxalate could be harmful because of the formation of calcium oxalate deposits in vital tissues or organs of the body. Patients with kidney stone problems are advised to limit dietary oxalate intake to 40-50 mg per day. In this study, commonly consumed green leafy vegetables (GLVs) such as spinach, Gotukola, cup leaves, Mukunuwanna, leeks, Kangkung, Hathawariya, Minchi, Kathurumurunga, Thebu, curry leaves, Bulath, manioc, cabbage and salad leaves were studied gravimetrically to determine the oxalate content. Edible portion of plant material was air dried, homogenized, refluxed for 12 hours, filtered, extracted with analytical grade diethyl ether, saturated with a calcium solution and then separated. The diluted and acidified solution with distilled water was titrated with standard KMnO4 assuming oxalate was the only oxidizable species. The experiments were carried out in triplicate for each species. Only a very few related studies are available in literature and the results were comparable. The results revealed that oxalate contents in GLVs ranged from (556.04 ± 1.60) mg to (3.20 ± 2.45) mg per 20 g of raw GLV portion. Also, the results confirmed that the GLVs can be divided into four categories based on the oxalate content as high (> 200 mg), medium (199 mg – 100 mg), low (99 – 10 mg) and undetectable (< 10 mg). Hathawariya, spinach, curry leaves and Kankung showed the highest amount of oxalate ranging from 556.04 ± 1.60 to 238.04 ± 1.84 mg per 20 g, while cabbage, salad leaves and leeks showed undetectable amount of oxalate ranging from 7.47 ± 1.84 to 3.20 ± 2.45 mg. It is interesting to note that commonly consumed GLVs by Sri Lankans have detectable amount of oxalate content which exceeds the minimum advisable level according to American Diabetes Association. Adding such GLVs to meal along with calcium supplements may worsen the health condition of kidney stone patients.
Cytotoxic effect of a resorcinolic lipid isolated from Mangifera zeylanica in a human cancer cell panel
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Rathnayaka, Rajitha K.; Samarakoon, Sameera R.; Ediriweera, M. K.; Tennekoon, K. H.; Adhikari, A.; Gunasekara, Dinara S.
Cancer remains a leading cause of death worldwide. Surgery, chemotherapy, radiotherapy, hormonal therapy and immunotherapy are considered as treatment options for cancer. Plants have played a vital role as a source of effective anti-cancer agents, and 60% of anti-cancer agents derived from natural sources. Mangifera zeylanica is a plant endemic to Sri Lanka and its bark has been use in traditional medicine to treat some cancers. Cytotoxic compounds such as quercetin, chatecin, mangiferin and bromomangiferic acids have been reported in the bark extracts previously. Cytotoxic effect of a resorcinolic lipid (RL) in estrogen receptor-positive breast cancer (MCF-7), triple-negative breast cancer (MDA-MB-231) and epithelial ovarian cancer (SKOV-3) cells has evaluated in a previous study conducted in our laboratory. This study was performed to evaluate cytotoxic effects of RL [5-((8Z, 11Z, 14Z)-hexatriaconta-8, 11, 14-trienyl) benzene-1, 3-diol], a compound isolated from hexane extract of the bark of M. zeylanica, in small cancer cell panel containing human hepatocellular carcinoma (HepG2), colorectal adenocarcinoma (Caco-2), malignant mucoepidermoid pluripotent carcinoma (NTERA-2), renal cell adenocarcinoma (ACHN), mucoepidermoid pulmonary carcinoma (NCI-H292), epidermoid carcinoma (A-431), endometrium adenocarcinoma (AN3CA) and triplenegative breast cancer cells (Hs578t) and normal embryonic kidney cells (HEK-293). Sulforhodamine B (SRB) assay was carried out to evaluate the cytotoxic effects of the RL on the cancer cell panel. Prior to the SRB assays, cancer cells were treated with RL at concentrations ranging from 1.5625 to 25μg/ mL and incubated for 48 h. Results of the SRB assay demonstrated that RL excreted a potent in vitro cytotoxicity on all cancer cell lines tested (IC50 in μg/mL; HepG2: 2.31, Caco-2: 1.59, AN3CA: 1.28, Hs578t: <1.00, NTERA-2: <1.00, ACHN: 1.42, NCI-H292: 2.84 and A-431: 1.63) with less cytotoxicity to normal embryonic kidney cells (HEK-293: 4.44). Ethidium bromide/ Acridine orange staining revealed morphological evidence of apoptosis (including chromatin condensation, nuclear fragmentation and changes in the size and shape) in cancer cells. Overall results of the current study provide preliminary evidence to prove that RL can be develop as a potential drug to treats several types of human cancers.
Detailed evaluation of methylated and acetylated products of cinnamon leaf oil against Aedes aegypti
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Medagedara, H. K.; Paranagama, P. A.; Gunaratna, Medha J.
Aedes aegypti is a known vector of several viruses including Yellow fever, Dengue, Chikungunya and Zika virus. Two potential Aedes aegypti mosquito repellents; methyl eugenol and acetyl eugenol were semi-synthesized using eugenol extracted from cinnamon leaf, which is the main constituent in cinnamon leaf as well as in other plant leaf extracts like maduruthala and clove oil. Methyl eugenol was semi-synthesized using methyl iodide as a methylation precursor and acetyl eugenol was semi-synthesized using acetic anhydride, triethylamine base and catalytic amount of DMAP. Synthesis reactions were monitored using TLC and products were purified using flash silica columns. Formations of desired products were confirmed using GC-MS analysis. A diluted series (0.6-8 mg/ mL) was prepared for these semi-synthesized compounds and for the cinnamon leaf extract using ethanol and tested separately for their mosquito repellency using arm-in-cage tests followed by standard WHO methods. Experiments were performed on twenty volunteers in triplicates. Effective dose (ED99) for each repellent was calculated using beta regression analysis. Current study suggests that all compounds tested were effective mosquito repellents. Their ED99 varied as; cinnamon leaf extract (5.80) > methyl eugenol (5.41) > acetyl eugenol (5.13). Acetyl eugenol could be a potential safe repellent as its ED99 was achieved at a lower concentration and due to the absence of any side effects on skin when applied. Both maduruthala and clove oil contained significant contents of eugenol and clove oil had slight amounts of acetyl eugenol which could be extracted to synthesize repellent compounds or use directly in future.
Determination of antibacterial activity of 6β-hydroxybetunolic acid and interaction with oxacillin
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Wickramasingha, W. G. D.; Jayasinghe, S.; Karunaratne, D. N.; Liyanapathirana, V.; Ekanayake, A.; Karunaratne, V.
Various strides have been undertaken with successful results in the treatment and cure of significant number of bacterial infections. However, many bacteria are becoming resistant to some of the prevailing drugs due to either the misuse or the prolonged use of the available antibiotics increasing the necessity for discovering new antibiotics to combat resistant microorganisms. Plants and their secondary metabolites can be considered as good sources of scaffolds to provide structurally diverse bioactive compounds as potential therapeutic agents and combination of them with standard antibiotic to obtain synergistic effect. The objective of this study was to determine the antibacterial activity of one of a lupeol type triterpenoid (6β-hydroxybetunolic acid) isolated from the bark of Schumacheria castaneifolia Vahl. which is an endemic plant to Sri Lanka and to determine the synergistic effect with Oxacillin. Antimicrobial activity of 6β-hydroxybetunolic acid was evaluated utilizing micro broth dilution assay in 96 well plates against two standard strains of Staphylococcus aureus, 4 strains of clinically isolated Methicillin resistant S. aureus, standard strains of Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, carbepenemas producing Kebsiella pneumonia and carbepenemas non-producing Kebsiella pneumonia and four strains of clinically isolated Acinetobacter sp. Synergistic effect of the combination of 6β-hydroxybetunolic acid and Oxacillin was tested against Standard strain of S. aureus and MRSA using checker board method. Results revealed that 6β-hydroxybetunolic acid shows significant antibacterial activity only against the Gram positive strains; MIC values of S. aureus (ATCC 29213), S. aureus (ATCC 29213), E. faecalis (ATCC 29212) and four MRSA strains were 32, 16, 32, 32, 32, 32, 16 ppm respectively. However MIC value of Oxacilin against S. aureus (ATCC 29213) was 0.25 ppm. 6β-hydroxybetunolic acid has synergistic effect with Oxacillin against S. aureus and additive effect against all the tested MRSA. These results concluded that the antibacterial activity of 6β-hydroxybetunolic acid is predominantly depending on the cell wall difference of the bacteria.
Determination of authenticity of palmyrah toddy using chemical tests
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Glanista, T.; Prabagar, J.; Suganja, T.; SriVijeindran, S.
Palmyrah toddy is one of the alcoholic drinks traditionally prepared by the fermentation of sweet sap from the young inflorescence of Palmyrah tree (Borassus flabellifer). It is a popular drink not only in Northern part of Sri Lanka but also in other parts of the country. It generates a high income for families who make the traditional toddy. There are some adulterated toddy samples available in the local market and can be made by the fermentation of sugar and starch solution. Identification of toddy samples, whether it is pure or artificial is a big challenge as both sweet sap and added sugar contain sucrose, which undergoes fermentation. Hence, this study was focused to identify the authenticity of Palmyrah toddy using qualitative analysis of compounds such as chloral hydrate, paraldehyde and starch and quantitative analysis alcohol content, acidity, Brix, sulfated ash, turbidity, conductivity and yeast count. Genuine toddy samples were obtained from different Palm Development Co-operative Societies. Adulterated toddy samples were collected form the market and artificial toddy samples were prepared in the laboratory using sugar and starch solution. Chloral hydrate and starch were present in the artificial toddy and artificial toddy samples are having significantly higher (p<0.05) alcohol content (5.5 - 6.2 % v/v), turbidity (2025-2511 NTU) and yeast count (20.8 x 106 – 25.2 x 106 cells/mL) than the genuine toddy samples (3.9 - 4.2 % v/v), (798 - 1023 NTU) and (15.9 x 106 – 16.5 x 106 cells/mL) respectively while there is no significant difference between genuine and artificial toddy in Brix, acidity and conductivity. The sulfated ash content of genuine toddy samples was found in the range of 0.45 to 0.52 g/100 mL and this content is significantly lower (p<0.05) in artificial toddy (0.05 to 0.10 g/100 mL). Therefore, chemical analysis could be used to identify the authenticity and the quality of Palmyrah toddy.
Determination of some metals in the processed durian seed powder containing chocolate aroma.
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Wijayahena, Mindula K.; Jayaweera, Champa D.
Durian is a tropical fruit with seeds which are usually discarded after consumption of the flesh. The seeds are round in shape; the color range from yellowish brown to reddish brown. We reported earlier that the processed seed powder of underutilized durian (Durio zibethinus Murr.) seeds contains chocolate odor active compounds which produce chocolate aroma. In this study, we analyzed some metals in the processed seed powder to determine the nutritional metal content in seed powder since it has not been reported in literature and to examine whether a loss in the metal content occurs during fermentation process. Durian seeds were fermented (FDS) and dried (DDS) to produce two types of seeds and they were roasted to produce the processed seed powder samples from each type. The samples were subjected to dry ashing followed by acid digestion for the evaluation of the minerals and trace elements of the processed seed powder of durian seeds by atomic absorption spectroscopy (AAS). The metal analysis was carried out for both DDS and FDS powders considering DDS powder as the control. The method was validated using the spiking technique. The calculated recovery percentages of selected minerals and trace elements were within 80-110%. Analysis of durian seed powder samples by AAS revealed the presence of metals; K (3.48±0.06), Na (2.33±0.04×10- 1), Ca (2.39±0.05×10-1) mg/g and trace elements; Cu (8.27±0.05×10-3), Fe (8.62±0.07×10-3) and Zn (6.67±0.04×10-3) mg/g. The mineral content determined in the durian seed powder is higher when compared to the previously reported content in the durian flesh. A significant difference was not found in the metal contents between DDS and FDS powders illustrating that the metal loss is negligible during fermentation.
Determination of total phenolic content (TPC) of Nymphaea nouchali and Nymphaea pubescens by Folin Ciocalteu method
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Sundaram, T. M.; Napagoda, M. T.; Wijesekera, K. D.; Wijayaratne, Gaya Bandara
Nymphaea nouchali (Nil Manel) and Nymphaea pubescens (Olu) are aquatic plants, and have a long history of use as food and folk medicine in many countries. Many phenolic compounds isolated from these two plant species have exhibited antioxidants properties and some simple phenolic compounds have shown to possess various pharmacological activities, including anti-inflammatory, antiproliferative, antioxidant and pro-apoptotic potential. The aim of the present study was to determine the content of total phenol in an extract from N. nouchali and N. pubescens flowers collected from Galle, Sri Lanka, by a UV/Vis spectrophotometric method. Aqueous methanol (80%) was used as the solvent to extract flowers including petals, stamens and pistil and all extracts were analyzed for TPC by Folin Ciocalteu method. Results were expressed in terms of gallic acid equivalence in (GAE)/g dry weight (DW) of flower part. N. pubescens petals contained 49.780 ± 0.626, stamens 37.581 ± 0.477 and pistil 31.889 ± 0.711, while N. nouchali petals showed 22.536 ± 0.383, stamens 38.702 ± 1.112 and pistil 30.119 ±1.116 GAEg-1. N. pubescens showed higher TPC in every plant part tested compared to N. nouchali and petal extract of N. pubescens showed highest TPC. Hence, N. pubescens flowers are a good source of antioxidants. Results emphasized that N. nouchali and N. pubescens extracts have high phenolic content and the importance of the use of natural products to treat pathological conditions.
Determination of water quality and suitability in a chronic kidney disease of unknown etiology (CKDu) prevalence area, Sri Lanka
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Botheju, W. S. M.; Liyanage, Janitha A.
Chronic Kidney Disease of unknown etiology (CKDu) is a global health obstacle that is presenting as kidney disease in patients who do not show common causative factors, such as diabetes or hypertension. Although the causative factors and major causes for CKDu prevalence are still in debate, most of the external factors which affect the disease are associated with drinking water. Therefore, this study investigated the water quality and suitability of drinking water in a CKDu prevalence area to assess its suitability for human consumption. The water samples were collected from 30 dug wells in Girandurukotte Grama Niladhari Division (GND), Badulla District which reported the highest number of CKDu patients and from Buddhangala GND in Ampara District (as reference sampling site) in dry season. Dissolved Oxygen (DO), Electrical Conductivity (EC) and Fluoride (F) were analyzed as on-site measurements. Calcium (Ca), Magnesium (Mg), Cadmium (Cd), Arsenic (As) were determined using Inductive Coupled Plasma Mass Spectrometry. Sulphate, Nitrate and Chlorides were analyzed using Ion Chromatography. Each analysis was performed in triplicates. The Water Quality Index (WQI) was calculated using standards of drinking water quality recommended by the World Health Organization (WHO). According to the results, pH, DO, EC, F, Ca, Mg, Cd, Cr, Pb, As, total hardness, sulphate, nitrate and chloride values in Girandurukotte GND were 7.03±0.08, 4.8±0.8 mg/L, 396.9±9.1 μS/cm, 1.64±0.04 mg/L, 1.05±0.90 mg/L, 202.85±5.60 mg/L, 0.124±0.074 μg/L, 54.75±0.54 μg/L, 0.20±0.05 μg/L, 30.64±8.60 μg/L, 83.60±4.02, 60.28±5.62 mg/L, 20.56±8.62 mg/L and 122.65±10.36 mg/L respectively. The results obtained for WQI in Girandurukotte and Buddhangala were 71.84 (51-75 poor) and 42.67 (26-50 good) respectively. Results indicate that water samples analyzed from Girandurukotte are not safe for human consumption and other domestic purposes while the water samples in reference site are safe for human consumption. Therefore, taking all necessary precautionary measures before the consumption can be recommended to avoid adverse health impacts.
Development of a face and body cleanser using Cocos nucifera (coconut) oil, coconut shell charcoal and rice husk charcoal
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Jayasooriya, J. A. C. T.; Udawatte, C. S.
Air pollutants and toxic elements can directly affect the skin as it is the outermost barrier protecting the body. In this study, a cleanser was formulated using charcoal, virgin coconut oil, and other local ingredients. An artificial sweat solution including NaCl, NH4Cl, acetic acid, lactic acid was treated with coconut shell charcoal (CSC) and rice husk charcoal (RHC) varying the particle size, dosage, and the contact time with the solution, in triplicates. The remaining organic acids, NH4 +, and Na+ were determined by formalin titrimetric method and flame photometry. CSC having the particle size of 0.25-0.50 mm exhibited higher adsorption towards the two main components in human perspiration; NaCl and NH4Cl than RHC, at an average contact time of 30 minutes. Therefore, CSC was used as the adsorbent. Virgin coconut oil was used as a moisturizer, an antioxidant, an emulsifying agent, sodium lauryl ether sulfate as the foaming agent and bee’s honey as the binding agent, a thickener, an antimicrobial and a humectant. Other ingredients used were kaolinite, sesame oil, and sweet orange essential oil. The pH of the product was 6; therefore, pH balanced. The product showed significant antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa when subjected to agar well diffusion method. The highest result was observed against Staphylococcus aureus, giving an inhibition zone of 2.5 cm for 100 mg of the product, while 5 μg of Ciprofloxacin showed an inhibition zone of 3.0 cm. The product was easily spreadable, washable, and had a thick consistency. Patch test was done by applying 400 mg of the product on the dorsal forearm of 10 volunteers with a diameter of 1 inch, for 30 minutes, then rinsed off with water. No adverse effects were exhibited. Therefore, this product can be considered safe, and it achieves the desired attribute as a cleanser.
Development of a herbal fairness cream using four medicinal plants
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Wimalasekera, H. N.; Paranagama, P. A.; Harapathdeniya, S.
There are reports in the public domain which state that artificially synthesized fairness creams have shown side effects on humans. The purpose of a fairness cream is to get a fairer skin by blocking harmful Ultraviolet (UV) rays which can activate the melanin biosynthesis in the body. When there is an excess production of melanin, it can lead to several hyperpigmentation diseases and finally result in a darker or tanned skin. This excess melanin formation can be inhibited by avoiding exposure to UV light, using tyrosinase inhibitors and anti-oxidants, which can reduce melanin proliferation. In this research study, a herbal fairness cream was prepared using four traditional medicinal plants found in Sri Lanka to inhibit excess melanin production in the body. The four plants chosen for this study were, Hemidesmus indicus (Heen Iramusu), Ixora coccinea (Rathmal), Hibiscus rosa sinensis (Pokuru Wadamal) and Citrus reticulata (Heen Naran). The plant extracts and the cream were separately subjected to anti-oxidant (DPPH and ABTS) assays and anti-tyrosinase assay. In addition, the anti-bacterial activity of this cream was studied. The methanol extracts of these four plant species displayed a high antioxidant activity and a significant tyrosinase inhibitory activity. The herbal cream was formulated using equal proportions of these extracts. Anti-tyrosinase studies of the cream revealed that it has a good anti-tyrosinase activity compared to the positive standard, Kojic acid. In addition, anti-bacterial studies revealed that the cream can inhibit bacteria Staphylococcus aureus and Bacillus subtilis. The ABTS assay showed that this polyherbal cream can act as an excellent antioxidant (IC50: 0.54±3.86) with respect to the control BHT (IC50:9.99±1.76). The cream was prepared using 100% natural ingredients which helped to enhance the therapeutic benefits of this cream. Thus, this cream can be used as a substitute for the synthetic fairness creams already available in the market.
Development of an herbal drink using Sri Lankan varieties of Sesbania grandiflora and Citrofortunella microcarpa and its antioxidant activity
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Cooray, P. P. D; Wickramasinghe, P. D. S. U
A Majority of individuals prefer ready-to-serve (RTS) beverages over preparing herbal drinks due to the busy lifestyle. The current study was focused on the development of a ready-to-serve herbal drink using the pulp of Sesbania grandiflora leaflets and Citrofortunella microcarpa fruit sac juice with sugar, table salt, and distilled water. According to previous studies, the major active compounds of the drink contain high antioxidant activity and nutrients which are considered beneficial for human health. A sensory evaluation was conducted by a trained group of tasters to choose the best sample with significant differences to taste, appearance, and aroma. pH value, titratable acidity, Brix value, reducing sugar activity, antioxidant activity, qualitative analysis of phytochemicals, microbial analysis, and shelf life of the herbal drink were determined. The herbal drink contained a pH value of 2.36 at 298.15 K, titratable acidity of 0.384% when the milliequivalent factor for citric acid is 0.064, and a Brix value of 11 at 293.15 K. The herbal drink contains the phytochemicals such as sterols, terpenoids, flavonoids, phenols, glycosides, and saponins which were identified from qualitative analysis, whereas alkaloids and tannins were absent. Antioxidant activity had a maximum of 71.48% DPPH radical scavenging activity (RSA) at 12.5% (v/v) concentration of drink in methanol and inhibition concentration 50 (IC50) was at 47% (v/v) concentration of the drink in methanol. The total plate count was 840 CFU/ml (colony-forming units per milliliter) and the estimated yeast and mold count was <250 CFU/ml, yet coliform, fecal coliform, and Escherichia coli had no growth for two days under optimum growth conditions. According to the study, the refrigerated sample had the least amount of microbial growth. Therefore, the herbal drink sans preservatives is recommended to be stored in the refrigerator.
Development of low-cost automated robot arm; its limitations and the validity of results through modified potentiometric experiments
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Perera, K. A. N. K.; Rodrigo, S.; Liyanage, I.; Umayanga, I.; Perera, B.; Nawarathne, D.; Perera, D.; Jiffry, N.; Sirimuthu, N.; Ekanayake, E. M. M. S.
Robotics is used widely in design, construction and operation, further also in control, sensory, feedback and information processing. Robotics arm performs a crucial task in all the above. Automation in a chemical laboratory will be a major breakthrough in terms of productivity, quality and the reproducibility of the results, improved safety, reduce the time and cost of the whole running process. To catalyze this revolutionized system performances, as a combination of engineering and chemistry, we developed an automated robot arm and validated its results while overlooking the limitations via modified potentiometric experiments. The idea behind this concept is to use this robotics hand in places where it can be used to replicate the action of a human hand and thereby substituting its purpose in places where a human hand cannot be used. During this experiment robot arm involved in measuring cell voltage by using a standard calibrated potentiometer in a thermostat water bath at different temperatures; where it produced steady results compared to the manual procedure under same conditions while saving a considerable working time. The potentiometric reading equipment IEEE 488 fitted with an Interface Scanner 740 and a GPIB (General Purpose Interface Bus) program was used to obtain a continuous record of the potentials while test solutions were moving on a belt. For the validation, reading taken by using the automated arm and manual readings for the same sample were statistically analyzed (n=181) using t-test, linear regression and Spearman correlation coefficients which clearly indicate no significant difference between them. In summary, this work described an inexpensive and simple method for the automated potentiometric titration. The only limitation encountered during this process was the servo motors used, have only a maximum rotation of 180⁰ for 1m radius semicircle within 75s. Therefore, the area of movement is restricted to a certain region of space, but the arm can move an object from one-point coordinate to another in the x, y and z axes which could be adapted to many applications other than in a chemical lab.
The development of novel photodegradable linear low-density polyethylene (LLDPE) and investigation of the antibacterial properties
(Institute of Chemistry Ceylon Adamantane House, Rajagiriya, Sri Lanka., 2020) Kandambi, D. P. H.; Mudiyanselage, T. Kuruwita; Udawatte, C. S.
Plastic does not decompose easily under natural conditions and the need for degradable polyethylene has become an important area of research. In this study, the suitability of using cinnamaldehyde, in its natural and synthetic forms, and benzophenone, as photo oxidative sensitizers were evaluated. The results showed that oxidative degradation of linear low density polyethylene (LLDPE) increased significantly with the incorporation of these materials. Oxidative sensitization increased significantly with incorporation of natural cinnamaldehyde, Best results for oxidative sensitization were obtained by incorporation of 20% by mass natural cinnamaldehyde. The polymer composite films were prepared using a polymer solution in toluene and 2 cm x 2 cm films were caste between glass slides. 10 samples of each type were analyzed. The extent and nature of degradation was evaluated using FTIR spectroscopy, percentage weight loss and surface analysis techniques. The auto oxidative degradation of the composite films was carried out by accelerated UV initiated degradation, and also under natural rooftop conditions. Embrittlement and color development with aging in the photosensitizer incorporated polymer films were noticeably evident, when compared with the nonincorporated polymer films under similar conditions. Since polymer films are used for food and drug packing applications, antibacterial properties of the composite films were evaluated for four bacterial strains, Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853) and Bacillus cereus (ATCC 11778) using agar disc-diffusion method. Cinnamaldehyde containing composite films displayed significant antibacterial properties against all four bacterial strains, whereas benzophenone containing films did not show antibacterial properties against these strains.