H.S. Garg

An antiviral sphingosine derivative from the green alga Ulva fasciata

A fraction showing in vitro and in vivo antiviral activity was isolated from the green alga Ulva fasciata found in the Indian Ocean off the West coast of India. The structure of its major component was established to be N-palmitoyl-2-amino-1,3,4,5-tetrahydroxyoctadecane on the basis of spectral studies.

Dysobinin, a new tetranortriterpene from Dysoxylum binectariferum

Abstract Dysobinin, a new tetranortriterpene of the meliacin group showing general CNS-depressant action and mild anti-inflammatory activity was isolated from the fruits of Dysoxylum binectariferum . Alkaline hydrolysis of dysobinin gave a new diol named dysobindiol. The structural elucidation of dysobinin and dysobindiol is described.

Ursane triterpenoids from Nepeta eriostachia

Abstract From the aerial parts of Nepeta eriostachiya two rare ursane triterpenoids, 2α,3α-dihydroxyurs-12-en-28-oic acid and 2α,3β-dihydroxyurs-12-en-28-oic acid, together with a new triterpene, nepetoic acid identified as 2α-methoxy-3β-hydroxyurs-12-en-28-oic acid were isolated as their methyl esters. Their structures were established by chemical and spectroscopic means.

An isoprenylated flavanone from leaves of Azadirachta indica

Abstract A new isoprenylated flavanone has been isolated from the leaves of Azadirachta indica and characterized as 8,3′-di-isoprenyl-5,7-dihydroxy-4′-methoxyflavanone on the basis of physical and spectroscopic evidence. This is the first report of an isoprenyl flavanone from the Meliaceae.

A triterpene glycoside from Scrophularia koelzii

Abstract A new triterpene glycoside, scrokoelziside B, was isolated from the aerial parts of Scrophularia koelzii and characterized as 3β- O -([β- d -glucopyranosyl (1 → 2), α- l -rhamnopyranosyl (1 → 3)]-β- d -fucopyranosyl (1 → 4)-β- d -glucopyranosyl)-olean-11.13 (18)-diene 23α, 28 diol on the basis of its 13 C NMR and 2D NMR data.

Koelzioside, an iridoid diglycoside from Scrophularia koelzii

Abstract A new iridoid diglycoside named koelzioside has been isolated from Scrophularia koelzii . The structure of koelzioside was elucidated by chemical and spectral analysis as 6- O -(2″,3″-di- O -cinnamoyl-4″- O -acetyl)-α- l -rhamnopyranosyl catalpol.

Two xanthone glucosides from Halenia elliptica

Abstract Two new xanthone- O -glucosides, 2,3,7-trimethoxyxanthone-1- O -glucoside and 2,3,5-trimethoxyxanthone-1- O -glucoside were isolated from whole plant of Halenia elliptica and identified through their acetates. Also present are four free xanthones, 1-hydroxy-2,3,4,7-tetramethoxy, 1-hydroxy-2,3,4,5-tetramethoxy, 1-hydroxy-2,3,7-trimethoxy, and 1-hydroxy-2,3,5-trimethoxyxanthone, oleanolic acid and sitosterol glucoside. A fraction rich in xanthone glucosides showed marked antiamoebic activity.

Ipolearoside: A new glycoside from Ipomoea leari with anti-cancer activity☆

Abstract Ipolearoside, a new glycoside with anticancer activity, has been isolated from Ipomoea leari Paxt. On acid hydrolysis in methanol, it gave the aglycone methyl ester, characterised as methyl 3,11-dihydroxyhexadecanoate. Ipolearoside is a complex glycoside of 3,11-dihydroxyhexadecanoic acid and glucose, rhamnose and fucose.

Xanthones of Halenia elliptica

Abstract Two new xanthones 1-hydroxy-3,6,8-trimethoxyxanthone, ellipticol, and 3,6,8-trimethoxyxanthone-1-O-primeveroside, ellipticoside, were isolated from the whole plant of Halenia elliptica and their structure elucidated by spectroscopic methods. The oxygenation pattern (1 3, 6, 8)in ellipticol and ellipticoside is hitherto unreported from natural sources and is of chemotaxonomic interest.

2′,3′-Dehydrosalannol, a tetranortriterpenoid from Azadirachta indica leaves

Abstract 2′,3′-Dehydrosalannol, a new meliacin related to salannin, has been isolated from the leaves of Azadirachta indica and characterized as 2′,3′-dehydrosalannol on the basis of its spectral data.