Axinellin A and B: Two New Pyrrolactam Alkaloids from Axinella sp.
Two new pyrrolactam alkaloids, axinelline A (1) and B (2), were isolated from the n-BuOH extract of marine sponge Axinella sp. The structures of these compounds were elucidated on the basis of spectroscopic methods (HR-ESI-MS, 1D and 2D NMR).
A novel D-ring unsaturated A-nor sterol from the Indonesian sponge, Axinella carteri Dendy
Investigation of the freeze-dried dichloromethane: isopropanol extract of the sponge Axinella carteri Dendy, 1889 (Demospongiae: Halichondrida: Axinellidae), collected from Derawan Island, Indonesia, has led to the isolation of a new A-nor sterol with rare D-ring unsaturation, 3β-(hydroxymethyl)-A-nor-5α-cholest-14-en-16-one (1). While the efficacy of the new compound is unknown, moderate cytotoxicity was observed in the fraction from which it was purified. A more polar portion of the extract afforded the known alkaloid dibromoisophakellin (2), previously isolated from an Axinella sp. The purification of the compounds was achieved on silica gel and Sephadex LH-20 supports and the identity of the compounds was established with the aid of 1D and 2D NMR spectroscopic experiments.
The Chemistry of the Semiconductor Industry
Overview. Semiconductor silicon. Group III-V compounds. Group II-VI semiconductors. Chemical vapour deposition. Plasma-enhanced chemical vapour deposition. Metal-organic vapour phase epitaxy. Liquid-phase epitaxy of III-V compounds. Photoresists. X-ray and E-beam resists. Wet etching. Polyimides. Molecular electronics. Computer modelling. Plasma etching. Polymers in plasmas.