The 3-O-fatty acid ester derivatives (C(12)-C(18)) of two pentacyclic triterpenic acids, ursolic acid and oleanolic acid, were synthesized under mild esterification conditions in excellent yields (80-85%) and screened for their antifeedant activity, together with the parent acids, against the agricultural pest tobacco caterpillar larvae (Spodoptera litura F) in a no-choice laboratory study. The Urs-12-ene-28-carboxy-3beta-octadecanoate and olean-12-ene-28-carboxy-3beta-hexadecanoate were found to exhibit exceptionally potent antifeedant activities at 50 microg/cm(2) concentration, even after 48 h.

Background and Aim: Natural antioxidants have gained unique attention in recent years. Because of the carcinogenicity of synthetic compounds, there is a dearth for antioxidants from natural origin. Currently, seagrasses, the marine plants have gained attention for their secondary metabolites. Hence, the present study aims to examine in vitro antioxidant activity of both leaf and rhizome extracts of six seagrass species and has not yet been investigated. Methods: Crude methanolic extracts of leaf and rhizome obtained, were evaluated for total phenolic contents using Folin-Ciocalteaus method. Antioxidant potential of seagrass extracts were evaluated using total antioxidant activity, DPPH, FRAP, ABTS assay, H 2 O 2 and NO 2 scavenging assay and the phenolic compounds present in potent extracts were profiled by HPLC. Results: Maximum phenolic content and antioxidant activity was exhibited by leaf and rhizome extracts of C. rotundata followed by H. uninervis. Higher DPPH radical scavenging activity was found in leaf (78.84 ± 0.87) and rhizome extracts (75.480 ± 0.97) of C. rotundata and the lowest scavenging activity was found in the leaf and rhizome extracts of H. ovata (12.01 ± 0.63 and 5.769 ± 1.14). Among six species, C. rotundata exhibited higher radical scavenging activity containing the potential phenolic compounds. Conclusion: Present study portrays that leaf and rhizome extracts of C. rotundata acts as a potential source of antioxidant compounds with predominant presence of caffeic acid and ρ-coumaric acid that paves a way for the application of these compounds in both food and pharmaceutical industries as a multipotent antioxidant.

Curcumin metabolites namely curcumin monoglucuronide and curcumin diglucuronide were synthesized using an alternative synthetic approach. The anti-oxidant potential of these curcumin glucuronides was compared with that of curcumin using DPPH scavenging method and Oxygen Radical Absorbance Capacity (ORAC) assay. The results show that curcumin monoglucuronide exhibits 10 fold less anti-oxidant activity (DPPH method) and the anti-oxidant capacity of curcumin diglucuronide is highly attenuated compared to the anti-oxidant activity of curcumin.

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An assessment on heavy metal (Al, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb and Zn) accumulation by seven seagrass species of Lakshadweep group of islands was carried out using multivariate statistical tools like principal component analysis (PCA) and cluster analysis (CA). Among all the metals, Mg and Al were determined in higher concentration in all the seagrasses, and their values varied with respect to different seagrass species. The concentration of the four toxic heavy metals (Cd, Pb, Zn and Cu) was found higher in all the seagrasses when compared with the background values of seagrasses from Flores Sea, Indonesia. The contamination factor of these four heavy metals ranged as Cd (1.97-12.5), Cu (0.73-4.40), Pb (2.3-8.89) and Zn (1.27-2.787). In general, the Pollution Load Index (PLI) calculated was found to be maximum for Halophila decipiens (58.2). Results revealed that Halophila decipiens is a strong accumulator of heavy metals, followed by Halodule uninervis and Halodule pinifolia, among all the tested seagrasses. Interestingly, the small-leaved seagrasses were found to be efficient in heavy metal accumulation than the large-leaved seagrass species. Thus, seagrasses can better be used for biomonitoring, and seagrasses can be used as the heavy metal sink as the biomass take usually long term to get remineralize in nature.

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Betulinic acid (I), a pentacyclic triterpene, on derivatization gives six compounds:  3β-hydroxylup-20(29)-en-28 oic acid methyl ester (II), 3β-acetoxylup-20(29)-en-28-oic acid (III), 3β-allyloxylup-20(29)-en-28-oic acid (IV), 3β-p-methylcinnamatoxylup-20(29)-en-28-oic acid (V), 3β-p-methoxycinnamatoxylup-20(29)-en-28-oic acid (VI), and 3β-tri-O-methylgallotoxylup-20(29)-en-28-oic acid (VII). Their antifeedent activity against the agricultural pest tobacco caterpillar larvae (Spodoptera litura F) in a no-choice laboratory study showed the active compounds are V, VI, and VII. Keywords: Antifeedent; betulinic acid derivatives; tobacco caterpillar; Spodoptera litura (F)

Free-living marine nematode diversity was analyzed between Avicennia marina and Rhizophora mucronata mangrove covers of the Vellar Estuary (southeast coast of India). A total of 4,976 specimens of free-living marine nematodes were collected in 56 species. Comparatively, a higher species richness was obtained for A. marina (52 species) than for R. mucronata (44 species), whereas 40 species commonly existed in both mangrove covers. A higher density of nematodes was found in sediments of sandy nature, whereas there was lower total organic carbon compared to silt/clay composition; epigrowth feeders were dominant over the other feeding groups based on organic enrichment in surface sediments. Principal component analysis clearly explained the relationship between the environmental parameters of various months. Higher R values of analysis of similarities revealed significant differences in nematode assemblages between months, and it was quite evident by non-metric multidimensional scaling. Diversity indices showed higher values in the dry months. RELATE analysis explained serial changes in nematode species composition between months, and a relationship between biotic and abiotic variables was clarified using the BIO-ENV procedure. Viscosia spp., Metachromadora spp., Theristus spp., and Sphaerolaimus spp. were candidate species of A. marina leaf interaction by observation.