Bioassay Directed Fractionation of Petroleum Ether Extract of Aerial Parts of Ceriops tagal: Isolation of Lupeol as the Nematicidal Agent against Cyst Nematode Heterodera zeae.

Plant parasitic cyst nematode Heterodera zeae is a pest, causing substantial economic losses in agriculture. Organic pesticides, based on plant products have emerged as eco-benign nematicidal agents. Ceriops tagal is a well-known marine medicinal plant which has not been evaluated against any nematode. Petroleum ether extract of the aerial parts of the plant (CTP), exhibited promising activity against infective stage larvae of H. zeae. On subjecting to classical solvent-solvent separation, it afforded petroleum ether soluble (CTP-S), methanol soluble (CTPMS-1, CTPMS-2) and insoluble (CTPM-IN-2) fractions, which exhibited activity against the cyst nematode within 24 h exposure. GC, GC/MS and HR-ESI-MS analyses of CTPMS-1 and CTPMS-2 fractions resulted in the identification of a number of compounds, including pentacyclic triterpenoids, lupeol (1), betunal (2), betulin (3), lupenone (4), betulonaldehyde (5), betulonic acid (7), methyl 3-acetoxy-27-O-(3,4-dihydroxy-E-cinnamoyl)-20(29)-lupen-28-oate (8) and ß-amyrin, along with phenylpropanoid esters, fatty acids and their derivatives, benzamide, and indole derivatives. CTPM-IN-2 which mainly contained lupeol (1) exhibited maximum nematicidal activity, with 91 % and 93 % mortality of the larvae of H. zeae, after exposure for 72 h at the concentration of 0.5 % and 1 %, respectively. Its fractionation and purification through column chromatography resulted in the isolation and identification of four lupane-type triterpenoids 1, 3, 4 and betulinic acid (6). One of its most abundant column fractions CC-9-18 (145 mg) which exhibited substantial activity, with 81 % mortality at the lowest concentration of 0.125 % after 48 h of incubation mainly contained lupeol. It seems lupeol, a wide spread bio-privileged triterpenoid is the nematicidal principle of the plant as its authentic sample showed LC50 value of 0.061 after 72 h exposure. It is for the first time that nematicidal activity is reported for any part of C. tagal and that of lupeol against H. zeae. Pentacyclic triterpenoids 1-8 are biosynthetically related. Of the twenty-four compounds isolated or identified in the present investigation only five constituents 1, 3, 6, 7 and palmitic acid have been isolated previously from C. tagal.

Isolation of metallic salts of cytotoxic clerodanes from medicinal plant Polyalthia longifolia var. pendula.

Isolation of sodium and potassium salt of kolavenic acid (1,2), as a mixture of (3:1) and sodium and potassium salt of 16 oxo-cleroda-3,13(14) E-dien-15-oic acid (3, 4) as a mixture of (1:1) are first time reported form reddish black ripe and green unripe berries of Polyalthia longifolia var. pendula respectively. Three known constituents obtained, were identified as cleroda-3, 13(14) E-dien-15-oic acid (kolavenic acid) (5), 16(R and S)-hydroxy cleroda-3,13 (14)Z-dien-15,16-olide (6) and 16 oxo-cleroda-3,13(14) E-dien-15-oic acid (7). Structures of all these compounds have been determined through spectral studies while metal analyses were carried out to confirm the structure of the salts. Compounds 3, 4 and 7 possess cytotoxic activity against lung (NCI-H460), oral (CAL-27) and normal mouse fibroblast (NCI-3T3) cancer cell lines. Diterpenoid (7), a bioprivileged, compound shows potent cytotoxic activity against oral cancer cell line (CAL-27) with IC50 11.3±0.6µg/mL in comparison with the standard 5-flourouracil (IC50 12.7±0.1µg/mL) and lungs cancer cell lines (NCI-H460) with IC50 5.3±0.2µg/mL as compared to the standard drug cisplatin (IC50 5.7±0.2µg/mL).