http://dr.lib.sjp.ac.lk/handle/123456789/759 Thu, 23 Apr 2026 10:24:43 GMT 2026-04-23T10:24:43Z http://dr.lib.sjp.ac.lk/handle/123456789/987 Synthesis and Attempted 2H Labeling of 2,4-Positions of 1,3, 8- Trihydroxynapthalene, An Intermediate of Fungal Melanin Biosynthesis Weerasooriya, M.K.B.; Simpson, T.J. 1, 3, 8 - Trihydroxynaehthalene (T3HN), an intermediate of fungal melanin biosynthesis was successfully synthesized using 3,5- dimethoxybanzoic acid as the starting material. 2-and 4- positions ofT3HN was attempted to label with deuterium as it is expected to be important to study the stereochemistry of the reduction of 1,3- dihydroxy ring ofT3HN. The study showed that similar to H-2 and H-4 protons of 1, 3, 6, 8 - tetrahydroxynapthalene (another intermediate offungal melanin biosynthesis) those of T3HN also rapidly exchange with the protons in the medium and T3HN does exist as an equilibrium mixture or tautomeric forms in pH 7 buffered aqueous solution. Hence stereochemical study of reduction of T3HN using 2-and 4-deuteratcd T3HN was impossible. Sat, 01 Jan 2000 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/987 2000-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/986 Species Ddiversity, Seasonal Variation and Capture Method of Small cCetaceans on the West Coast of Sri Lanka Ilangakoon, A.D.; Ratnasooriya, W.D.; Miththapala, S. Species diversity, seasonal variation and capture methods were examined, in small cetacean catches and offshore sightings at the fishing sites and adjacent waters of Beruwal a and Negombo, on the west coast of Sri Lanka. from May to October 1994. 325 and 263 individual specimens of 12 and 9 species of small cetaceans (Stenella longirostris, Stenella coeruleoalba; Stenella attenuata, Tursiops truncatus, Grampus griseus, Peponocephala electra, Pseudora crassidens, Feresa attenuata, Kogia breviceps, Kogia simus, Steno bredanensis, Lagenodelphis hosei) were recorded in the landings at Beruwala and Negombo respectively. Offshore sightings contained 114 and 565 individuals, of two species (Stenella longirostris, Tursiops truncatusi off Beruwala and Negombo respectively. Species diversity between sites was not significantly different for the catch but was significant for sightings, while diversity between catch and sightings at each site was significantly different. Seasonal variation was observed in peak catches but there was no clear seasonality for offshore sightings. Capture method did not differ significantly between sites indicating increased harpooning. Many species not sighted offshore were found in catches at both sites, indicating even deep sea stocks of small cetaceans are exposed to threat by fisheries. The finding that intentional harpooning is spreading both in area and extent should be noted and investigated further. Sat, 01 Jan 2000 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/986 2000-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/985 Sex Ratio and Size Range of Small Cetaceans in the Fisheries Catch on the West Coast of Sri Lanka Ilangakoon, A.D.; Miththapala, S.; Ratnasooriya, W.D. This study examined the sex ratios and size range of small cetaceans caught on the west coast of Sri Lanka, in the fish landing sites of Beruwala and Negombo, where accidental entrapment and intentional harpooning occurs. Monitoring was done from May to October 1994. A total of 588 specimens of 12 species (Stenella longirostris, Stenella coeruleoalba, Stenella attenuata, Tursiops truncatus, Grampus griseus, Peponocephala electra, Pseudo rea erassidens, Feresa attenuata, Kogia brevieeps, Kogia simus, Steno bredanensis, Lagenodelphis hose i) were recorded. The proportion of sexes was significantly different between sites. In most species females were longer than males but there was no significant sexual dimorphism in any species recorded. In most commonly caught species a larger percentage were juveniles and sub-adults. The study concludes that there is a female bias in the catch at Beruwala with the avera! number of females caught being significantly higher than the number of males. A significant difference between sites in the size of males of the species Stenella longirostris and females of Tursiops truncatus indicates that more than one form (coastal and offshore) of these species may occur around Sri Lanka, similar to previous records from the eastern tropical Pacific for S. longirostris and from the north Pacific for T truncatus. A larger percentage of juveniles and sub-adults being caught indicates the possibility of an adverse impact on populations in the future due to an eventual dearth of breeding adults and diminishing replacement levels. Sat, 01 Jan 2000 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/985 2000-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/984 Purification of NADP Dependent, 1,3,6,8 -Tetrahydroxynaphthalene Reductase from Verticillium dahliae brm - 1(ATCC 44571) Weerasooriya, M.K.B.; Simpson, T.J. NADPH dependent 1,3,6,8- tetrahydroxynaphthalene Reductase, one of the key enzymes of 1,8-dihydroxy melanin (DHN melanin) biosynthesis was isolated from verticillium dahliae brm-I (ATCC 44571) and purified to near homogeneity (as shown by SDS-PAGE), using ammonium sulphate fractionation, ion exchange chromatography on DEAE Cellulose, FPLC Mono Q anion exchange and Superose - 12 gel filtration chromatography, Fold purification and yield of the enzyme were found to be 1423 and 0.47% respectively, Specific activity ofthe final enzyme fraction was 79,7 (nmole/ mg.min) Approximate molecular weight of the purified enzyme was determined as-24 kDa by Superose-12 gel filtration chromatography, A satisfactory HPLC based enzyme assay was also developed for thepurification of enzyme Sat, 01 Jan 2000 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/984 2000-01-01T00:00:00Z