Bioactivity-guided fractionation of extracts of roots and leaves of Cajanus cajan afforded 8 compounds: betulinic acid, biochanin A, cajanol, genistein and 2'-hydroxygenistein, longistylin A and C, and pinostrobin. The two stilbenes, longistylin A and C, and betulinic acid showed a moderately high in vitro activity against the chloroquine-sensitive Plasmodium falciparum strain 3D7.

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Bioguided fractionation of extracts of Aframomum latifolium and A. sceptrum (Zingiberaceae) resulted in isolation of (+)-( S)-nerolidol and seven labdanes, coronarin B, galanal A and B, galanolactone, ( E)-8beta,17-epoxylabd-12-ene-15,16-dial, (+)-( E)-labda-8(17), 12-diene-15,16-dial and its diethyl acetal, the latter being presumably an isolation artefact. The labdanes show a modest in vitro activity against a chloroquine-sensitive Plasmodium falciparum strain.

Fungal pathogens continue to pose challenges to humans and plants despite efforts to control them. Two coumarins, robustic acid and thonningine-C isolated from Millettia thonningii, show promising activity against the fungus Candida albicans with minimum fungicidal concentration of 1.0 and 0.5 mg/mL, respectively. Molecular modelling against the putative bio-molecular target, lanosterol 14α-demethylase (CYP51), revealed a plausible binding mode for the active compounds, in which the hydroxyl group binds with a methionine backbone carboxylic group blocking access to the iron catalytic site. This binding disrupts the synthesis of several important sterols for the survival of fungi.

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Product isotope effects, given by the product ratio XC6H4CHs/XCBH4*CH,D, have been measured for cleavage a t ca. 21 ' of some compounds of the type XC6H4-CH,*MMe, ( M = Sn or Si) in 1 : 1 MeOH-MeOD containing sodium methoxide (2 mol 1-l). Valuesfor various substituents X and M = Sn are: p-Me, 2.4; H, 2.1 ; p-CI, 2-1 ; rn-CF,, 2.1 (all rt0.15) ; and for M = Si ; H, 1 .I 7 ; rn-OMe, 1.25 ; p-CI, 1.07 ; rn-CF,, 1 .I 9 (all k0.05). The corresponding value for C6FS*CH2.SiMe, is 1 .I 6. Overall solvent isotope effects, (ksH/ksD), given by the individual rates in non-deuteriated and deuteriated media at 50" have been determined for the compounds with X = m-CF,; the values are : for M = Si, 0-50 in MeOH or in MeOH containing 18.6 mole % H, O ; for M = Sn. 0.95 in MeOH and 0.97 in MeOH containing 20 mole % H, O.It is concluded that, in the cleavage of the tin compounds certainly, and probably also in that of the silicon compounds, a free carbanion is not formed. It is suggested that the rate-determining step involves proton transfer from the solvent to the carbon atom of the breaking M-CH2*C6H4-X bond, with the MeO-M bond fully or almost

The petrol extract of the rootbark of Milletia Thonningii obtained by column chromatography afforded sixteen different crystalline samples to be isolated. The crystal structures of two of these compounds, O,O‐Dimethylalpinumisoflavone (I) and 5‐O‐Methyl‐4'‐O‐(3‐methyl‐but‐2‐en‐1‐yl)alpinumisoflavone (II) are being reported here. (II) has two independent molecules in the asymmetric unit and differs from (I) in a longer side chain attached to C(15) of the phenyl ring. The structural features of the three molecules in the title compounds are reported and compared. The derivatives, being subject of this article are the first reported crystal structures where the isoflavone fragment is fused to a further six membered ring that results in a tricyclic ring system. The benzopyrone fragments are planar. The dihedral angles between the benzopyrone fragment and the phenyl ring being 55.38(6)° for (I) and 44.75(15)° /44.64(15)° for the respective independent molecules of (II) are within the range of values observed for similar structures.