Isolation and Characterization of Sclerienone C from Scleria striatinux.

Herein, we report the isolation and characterization of sclerienone C, a novel sesquiterpene isolated from the methylene chloride/methanol (1:1) extract of Scleria striatinux that we have deduced to have structure 1. This medicinal spice of Cameroon has been shown to display antimicrobial and antiplasmodial activities. The isolation and purification involved a combination of methods including silica gel column chromatography, Sephadex LH-20, and semi-prep HPLC separations.

Preparation and antimalarial activity of a novel class of carbohydrate-derived, fused thiochromans.

A novel class of fused thiochroman derivatives has been prepared by an efficient and versatile synthetic procedure involving nucleophilic displacement of the side-chain iodo substituent in 2-deoxy-2-C-iodomethyl glucosides by thiophenolate ions, and subsequent intramolecular C-glycoside formation. A range of aromatic substituents is tolerated, and the subsequent facile selective oxidation of the sulfur to the sulfoxide or sulfone level expands the range and molecular diversity of the series of compounds. A selection of the sulfoxide and sulfone derivatives bearing lipophilic substituents on the aromatic portion were found to have antimalarial activities in the low micromolar range.

Regiospecific synthesis of 2-halo-3-(2'-glucalyl)benzo[b]thiophenes.

A regiospecific synthetic strategy for the synthesis of 2-chloro-3-substituted benzo[b]thiophenes is developed via a dichlorocarbene insertion and sigmatropic rearrangement of an in situ generated ylide. The current protocol provides a reversed regiochemistry to the commonly employed electrophilic cyclization reaction for the synthesis of benzo[b]thiophenes and access to their hitherto under-represented chlorinated derivatives.

Stereoselective synthesis of thiochromenes via intramolecular tandem thio-Michael addition of in situ generated α,β-unsaturated aldehydes.

An efficient and highly stereoselective strategy for the synthesis of 2,3-substituted thiochromenes having a complex and easily transformable group at the stereogenic center has been developed via a tandem thio-Michael addition reaction of an in situ generated α,β-unsaturated aldehyde sugar derivative. The protocol is superior to reported protocols in that the carbohydrate-derived substituent at the stereogenic center of the thiochromene is versatile and is amenable for further transformation.

1-O-Acetyl-3,4,6-tri-O-benzyl-2-C-bromo-methyl-2-de-oxy-α-d-glucopyran-ose.

In the title compound, C30H33BrO6, the pyran-ose ring adopts a chair conformation. Two of the O-benzyl phenyl rings lie almost perpendicular to C/C/C/O plane formed by the ring atoms not attached to these O-benzyl phenyl rings, and form dihedral angles of 85.1 (2) and 64.

3,4,6-Tri-O-acetyl-1,2-[(S)-ethyl-idene]-β-d-mannopyran-ose.

In the title compound, C(14)H(20)O(9), the six-membered pyran and the five-membered dioxalane rings adopt chair and twisted conformations, respectively. In the crystal, the mol-ecules are linked by C-H⋯O inter-actions.

Okundoperoxide, a bicyclic cyclofarnesylsesquiterpene endoperoxide from Scleria striatinux with antiplasmodial activity.

Okundoperoxide (1) was isolated by bioassay-guided fractionation of extracts from Scleria striatinux (syn. S. striatonux).