Sohail Malik

Salvadoricine: a new indole alkaloid from the leaves of Salvadora persica

A new indole alkaloid salvadoricine (I) has been isolated from Salvadora Persica. Its structure was elucidated by spectral analysis and confirmed by synthesis. This constitutes the first report of naturally occuring 3-acetylindole alkaloid.

Mass spectrometry studies of a novel digoxin-like substance (DLIS-2) isolated from human plasma ultrafiltrate

Two unique low molecular weight (531) compounds with both digoxin-like immunoreactivity and Na, K-ATPase inhibitory properties have been isolated from human plasma. One of these, digoxin-like substance 2, (DLIS-2), was studied by fast atom bombardment mass spectrometry and collisionally activated dissociation mass spectrometry/mass spectrometry. The fragment patterns were interpreted as being derived from a lysophosphatidyl serine containing a novel 19:4 fatty acid side chain. The molecular formula C25H42O9NP is consistent with these observations.

Biosynthetic studies of marine lipids 18. Biosynthesis of 3β-(hydroxymethyl)-A-nor-5α-cholest-15-ene in the marine sponge phakellia aruensis

Abstract Through appropriate labeling experiments, it was shown that the unusual sterol 3β-(hydroxymethyl)-A-nor-5α-cholest-15-ene ( 1 ) is generated by ring contraction of dietary cholesterol followed by the introduction of the 15–16 double bond, rather than by ring contraction of 15-dehydrocholesterol ( 4 ).

Minor and trace sterols in marine invertebrates. 61. Isolation and structure elucidation of new A-nor sterols from the marine sponge Phakellia aruensis.

An examination of the Australian sponge Phakellia aruensis led to the isolation and identification of sterols with six different nuclei. Eight new sterols were isolated which included three delta 15-A-nor sterols, three delta 7-A-nor sterols, and two saturated A-nor sterols. Their structures were established through mass spectrometry and 1H-NMR spectral studies.