Antileishmanial, antimicrobial and antifungal activities of some new aryl azomethines.

A series of eighteen azomethines has been synthesized by the reaction of appropriate primary aromatic amines with aryl and/or heteroaryl carboxaldehydes. The synthesized azomethines have been evaluated for their in vitro antileishmanial, antibacterial and antifungal activities. The results revealed some antifungal activity of most of the synthesized compounds, whereas the antileishmaniasis activity results highlighted that all synthesized azomethines inhibited parasite growth and most of them showed highly potent action towards Leishmania major promastigotes.

Cucurbitacin glucosides from Citrullus colocynthis.

A new cucurbitacin glucoside 2-O-beta-D-glucopyranosyl-16alpha-20R-dihydroxy-cucurbita-1,5,23E,25(26)-tetraen-3,11,22-trione (1) has been isolated from the methanolic extract of the fruits of Citrulluscolocynthis. The structure has been assigned on the basis of spectral analysis including 1D and 2D NMR techniques. In addition 2-O-beta-D-glucopyranosyl-cucurbitacin B (arvenin I) (2) and 2,25-di-O-beta-D-glucopyranosyl-cucurbitacin L (3) are reported for the first time from this species.

Structure determination of ursene-type triterpenes by NMR techniques.

Two new ursene-type triterpenes, nudicauline A and nudicauline B, have been isolated from Launaea nudicaulis. Their structures have been assigned as 3beta-hydroxy-urs-11-ene (1) and 3beta-acetyl-urs-11-ene (2), respectively, by extensive NMR studies. In addition, olean-11,13(18)-diene (3), 3beta-hydroxy-13(28)-epoxy-urs-11-ene (4) and 3-keto-13(28)-epoxy-urs-11-ene (5) are also reported for the first time from this species.