Amarasinghe, N. R.2024-08-162024-08-162007https://ir.lib.pdn.ac.lk/handle/20.500.14444/584This study consists of two parts. Part I describes the chemistry and bioactivity of the fruits of Artocarpus altilis (Par.) Fosb. and Part If describes the chemistry and bioactivity of the fruits of Flacourtia indica (Burm. F.) Part I Arttocarpus aitilis (sinhala: rata-del) is a moderate size tree and widely cultivated in tropics. It is commonly found in home gardens and economically important as a staple crop. The fruits of 4. altilis are known as breadfruit and it is cooked as a starchy staple. The dried powdered whole fruits of A. aftilis were defatted with n-hexane and extracted with ethyl acetate and methanol at room temperature. Preliminary investigations indicated the presence of antifungal compounds in both extracts on TLC bio-autography method against Cladosporium cladesporioides. Chromatographic separation of the ethyl acetate and methanol extracts afforded twelve compounds and identified as (E)-2,4,3°5’- tetrahydroxystilbene (60), (E)-4-(3-methyl-E-but-1-enyl)-3,5,2’,4’ -tetrahydroxystilbene (81), (E)-4-isopentenyl-3,5,2’,4’-tetrahydroxystilbene (10), 2-(3,5-dihydroxyphenyl)- benzofuran-6-ol (82), 2-(2,4-dihydroxyphenyl)-5,7-tetrahydroxychroman-4-one (5), 5,7,2’,4°-tetrahydroxyflavone (83), 6-(3-methyl-Z-but-1-enyl)5,7,2’,4’-tetrahydroxy flavone (7), 6-isopentenyl-5,7,2’,4’-tetrahydroxyflavone (84), cycloartenyl acetate (73), 3 β-acetoxyolean-12-en-11-one (85), βsitosterol (80), 3-O-β-D-glucopyranosylsitosteral (86) by the detailed analysis of NMR and mass spectral data. Antifungal activities of compounds 5, 7, 10, 81, 82 and 84 were tested against seven plant pathogens (A/ternaria sp., Aspergillus sp., Colletotrichum sp, Cladosporium cladosporioides, Fusarium sp., Geotrichum sp. and Rhizctonia sp) using disc diffusion method and TLC bio-autography method for C. cladosporioides. Only compounds 7, 10, 81, and 82 showed an antifungal activity. Compound 10, 81 and 82 were active against all the fungi and among them 82 showed the highest activity on all the fungi. Compound 7 did not show any activity against Aspergillus sp., Calletotrichum sp. and Geotrichum sp. under the tested concentrations. Qualitative and quantitative analysis of the antioxidant activity of these isolates were carried out using DPPH (2,2’-diphenyl-1-picrylhydrazyl) radical scavenging assay. 2- (3,5-dihydroxyphenyl)-benzofuran-6-0l (82) showed the highest antioxidant activity having a [C(50) value 2 ppm in comparison with ascorbic acid (3.4 ppm) and butylated hydroxy anisole (3.0 ppm). Cytotoxicity of these isolates were carried out using brine shrimp (Artemia salina) micro-well cytotoxic assy. Compound 82 showed a highest cytotoxic activity having a LC(50) of 20 ppm. Lettuce seed (Lactuca sativa) germination assay was carried out to study the phytotoxic activity. Only compounds 10 and 82 showed a phytotoxic activity. Compound 82 completely inhibited the germination of the seeds at 1000 ppm level while the shoot growth was completely inhibited at 250 ppm. part II Flacourtia indica (sinhala: uguressa) is a tree of moderate size and widely cultivated in tropics and subtropics. In Sri Lanka it is cultivated in mid and low country for its edible fruit as well as an ornamental plant. The red coloured juice of the fruits of F. indica was filtered through a Buchner funnel. The n-BuOH extract of the fruit juice was chromatographed over columns of silica gel, RP-18 silicagel, sephadex LH-20 and PTLC. The final purification using reverse phase HPLC furnished four compounds including a new natural product, 4-oxo-2-cyclo pentenylmethyl 6-O0-(E)-p-coumaroyl--D-glucopyranoside (48) named flacourside, together with three known compounds, methyl 6-O-(E)-p-coumaroylgiucopyranoside (32), a and anomers of 6-0-(E)-p-coumaroy!glucopyranose (33/ 54). Qualitative and quantitative analysis of the antioxidant activity of 48, 52, 53 and 54 were carried using DPPH radical scavenging assay. None of them showed a significant activity.en-USChemical ScienceBioactivity of fruitsThesis