Muhammad Zahid

Taraxacin, a new guaianolide from Taraxacum wallichii.

A new guaianolide, taraxacin (1), and a known sesquiterpene ketolactone (2) have been isolated from an ethyl acetate-soluble part of a methanolic extract of Taraxacum wallichii. The structure of 1 was established using NMR, MS, and X-ray crystallographic methods. The (13)C NMR data of 2 is also being reported for the first time.

Flavonoids of Tephrosia purpurea

The isolation and NMR spectra of tephrosin, pongaglabol, and semiglabrin from Tephrosia purpurea aerial parts are reported.

Pharmacological activities of crude acetone extract and purified constituents of Salvia moorcraftiana Wall.

The crude acetone extract of aerial parts of Salvia moorcraftiana Wall. was screened for various biological activities including Lemna bioassay, antifungal, antibacterial, leishmanicidal, insecticidal activities and brine shrimp cytotoxicity. It was found to possess strong phytotoxic activity against Lemna aequinoctials Welve. and moderate antifungal activity against animal and plant pathogens. The purified chemical constituents were tested for enzyme inhibition activity. Two constituents (compounds 3 and 8) were found to be effective inhibitors of alpha-glucosidase.

A convenient method for the synthesis of cyclic trithiocarbonates on carbohydrate scaffolds

Abstract An efficient regio- and stereoselective method for the synthesis of cyclic trithiocarbonates on carbohydrate skeleton is described. A freshly prepared solution of sodium trithiocarbonate reacts with cis-oriented epoxytriflate pentoses 7–11 to yield the corresponding cyclic trithiocarbonates 12–16 . Structures of all new compounds are established through MS, 1H and 13C NMR techniques.

Benzoic acid derivatives from Stocksia brahuica

Abstract Two new benzoic acid derivatives, ethyl 3,5-dihydroxy-4-methoxybenzoate and 2-hydroxy-3-methylbenzoic acid, have been isolated from the aerial parts of Stocksia brahuica. They have been identified by mass and NMR spectroscopy. 3,4,5-Trihydroxybenzoic acid, 3,4,5-trimethoxybenzoic acid, methyl 4-hydroxybenzoate and n-propyl 4-hydroxybenzoate have also been isolated for the first time from this source.

Eight New Diterpenoids from Euphorbia decipiens

A reinvestigation of Euphorbia decipiens with a modified extraction procedure resulted in the isolation and structure elucidation of eight new myrsinane-type diterpene esters (see 3u2009–u200910). Moreover, revised structures are proposed for decipinone B (1) and C (2) on the basis of X-ray-diffraction analyses. The structures of the compounds were elucidated by means of different spectroscopic methods, including 1D- and 2D-NMR studies.

Phytochemical study of Salvia moorcroftiana.

Four known flavonoids were isolated from the aerial parts of Salvia moorcroftiana.

Coumarins from the aerial part of Halocnemum strobilaceum.

Four known coumarins, coumarin (1), 7-hydroxy-3-methylcoumarin (2), oreoselone (3) and heraclenin (4), were isolated from aerial part of Halocnemum strobilaceum. Their structures were determined by 1 and 2-D NMR techniques.

Two New C-Glycosylflavones From Silene Conoidea

Abstract The butanol-soluble part of the methanolic extract of Silene conoidea afforded two new flavone glycosides having C-C linkage between C-8 and C-1″: 8-C-(4″-O-α-L-rhamnopyranosyl)-β-D-glucopyranosyldiosmetin (1) and 8-C-(4″-O-α-L-rhamnopyranosyl)-β-D-glucopyranosylapigenin (2). Both the glycosides were purified by HPLC and characterized spectroscopically. In addition to 1–2, α-spinasterol (3) and its giucoside (4) have also been reported for the first time from the investigated source.

Three New Diterpenoids from Euphorbia cheiradenia

Three new diterpene esters, cheiradone (1), cheiradone A (2), and cheiradone B (3), were isolated from the aerial parts of Euphorbia cheiradenia, collected in Iran. The structures were determined using different spectroscopic methods, including 1D and 2D NMR and X-ray diffraction analysis.