N. Srinivasa Reddy

Rameswaralide, a novel diterpenoid from the soft coral Sinularia dissecta

Abstract Rameswaralide ( 4 ), a novel diterpene having a 5-7-6 tricyclic skeleton has been isolated along with known terpenes, africanene, 4,5- seco -african-4,5-dione, β-elemene and isomandapamate ( 3 ) from the soft coral Sinularia dissecta from the Mandapam coast, South India. The structure and stereochemistry of rameswaralide ( 4 ) were determined using spectroscopic methods and confirmed by selective reduction of the unusually stable enol group of 4 to form dihydrorameswaralide ( 5 ).

S-(+)-methyl ester of hanishin from the marine sponge Agelas ceylonica.

In a continuation of a search for biologically active molecules from marine organisms (Venkateswarlu et al., 1999) we investigated the sponge Agelas ceylonica belonging to the family Agelasidae. The sponge was collected at a depth of 30 f by skin diving near the Mandapam coast (N 173, E 833) India, during October 1997. A voucher specimen (IIC } 338) has been deposited at the museum of National Institute of Oceanography, Goa, India.

A Novel C-27 Nor Steroid from the Marine Sponge Petrosia Testudinariaα

Abstract A novel steroid 23-ethyl, 24-methyl, 27-nor cholesta-5, 25-dien-3β, 23-diol (1) and two known bromopolyacetalenes xestospongicacid methylester (2), its stereoisomer 3 have been isolated and characterized by the study of spectral data.

A Novel Polyhydroxylated Epoxy Steriod From the Soft Coral Sinularia Sp

Abstract A novel polyhydroxylated epoxy steroid (1) has been isolated from the soft coral Sinularia sp. and characterized by the study of spectral data.

Acid catalysed rearrangement of Δ 9,15 -africanene: a cytotoxic sesquiterpene

Acid catalysed rearrangements of Δ9,15-africanene, a cytotoxic sesquiterpene isolated from the soft corals of the genus Sinularia, have been studied for the first time and a marked difference was observed between the compositions of the conversion products with and without refluxing conditions.