Diverse Metabolites of Coral Reef Invertebrates

Chemical investigation on the constituents of the nudibranch Chromodoris willani collected at Zampa in Okinawa resulted in the isolation of two new compounds deoxymanoalide (1) and deoxysecomanoalide (2) and its prey sponge gave two known compounds manoalide (3) and secomanoalide (4). A new collection of the gorgonian Isis hippuris was obtained at Izena in Okinawa gave four new gorgosterols (8-11), along with four known members (12-15) that are highly functionalized with oxygen-containing substituents. A soft coral, Paraminabea sp., collected at Manza in Okinawa yielded one new steroid (19) and five known cholic acid type keto-steroids (20-24) possessing enone or dienone A-ring and known desmosterol (25). A sponge collected at Manza in Okinawa gave two new spongian-class diterpenes (27 and 28) together with two known compounds chromodorolides B (29) and C (30). The structures of all new compounds were elucidated on the basis of detailed spectroscopic analysis and chemical transformations. All compounds were evaluated with respect to various biological activities including cytotoxicity using NBT-T2 rat bladder epithelial cells, antimicrobial activity and PLA2 assay.

Autorentext

Dr. Mohammad Helal Uddin, PhD: Marine and Environmental Sciences, 2010 from University of the Ryukyus, Japan. Faculty: Department of Chemistry, since August 1999 and Chairman: Department of Applied & Environmental Chemistry, since August 2011, University of Chittagong, Bangladesh. He has authored several articles in reputed international journals.