Michel Devys

Brassilexin, a novel sulphur-containing phytoalexin from Brassica juncea L., (Cruciferae)

Structure 1 is established for brassilexin, a new sulphur-containing phytoalexin isolated from the leaves of Brassica juncea (Cruciferae), on the basis of spectrographical data (UV, IR, high resolution MS, 13C and 1H NMR).

Pigments from Nectria haematococca: Anhydrofusarubin lactone and nectriafurone

Abstract The structures of anhydrofusarubin lactone and of nectriafurone, two new naphthoquinone pigments isolated from the fungus Nectria haematococca , are

Pollen sterols—a mass spectrographic survey

Abstract The fractions of sterol in pollens from fifteen species of plants in eleven families were analyzed by mass spectrometry. 24-Methylene-cholesterol was the principal sterol of red clover (Trifolium pratense L.), saguaro cactus (Carnegiea gigantea (Engelm.) Britt. & Rose), mustard (Brassica nigra (L.) Koch), London-rocket (Sisymbrium irio L.), rye (Secale cereale L.), timothy (Phleum pratense L.), and sweet corn (Zea mays var. saccharata (Sturtev.) Bailey). β-Sitosterol was the principal sterol of mule fat (Baccharis viminea DC.), juniper (Juniperus utahensis (Engelm.) Lemm.), heartsease (Polygonum sp.), waterleaf (Hydrophyllum capitatum Dougl.), Scotch pine (Pinus sylvertris L.), European alder (Alnus glutinosa (L.) Gaertner), and Lombardy poplar (Populus nigra var. italica Muenchh.). Cholesterol was the principal sterol of cottonwood (Populus fremontii S. Wats.). The presence of cholesterol in the pollen from cottonwood has been confirmed by gas-liquid chromatography. 24-Methylene-cholesterol in saguaro cactus was further verified by the preparation of 24-ketocholesterol by ozonolysis, saponification of the acetate, and then a direct comparison of the thin-layer chromatograph of the free sterol with an authentic sample of 24-ketocholesterol.

Cyclobrassinin sulphoxide, a sulphur-containing phytoalexin from Brassica juncea

Abstract Cyclobrassinin sulphoxide, a new sulphur-containing phytoalexin, was isolated from elicited leaves of Brassica juncea , and identified on the basis of physico-chemical data (IR, high resolution MS and 1 H NMR). The results so far obtained within this series of natural compounds are discussed in relationship with their possible biosynthesis.

Biosynthesis of cholesterol from pollinastanol in the tobacco Nicotiana tabacum

Abstract Pollinastanol (I), tritiated in position 3, is incorporated into cholesterol by leaves of the tobacco Nicotiana tabacum Wisconsin with a 1% yield. As expected, however, C28 and C29 sterols were unlabelled. The significance of these results is discussed.

Incorporation of serinol derived acyclic nucleoside analogues into oligonucleotides: Influence on duplex and triplex formation

Abstract Phosphoramidites 6a-c were readily prepared by an original route and used to incorporate serinol derived units I–III in oligonucleotides which, compared to their natural analogues, exhibited a decreased htbridization capacity for duplex and triplex formation.

A simple synthesis of tropones and related compounds

Abstract Cyclohexa-2,4- and 2,5-dienones bearing at position 2 or 4 α dihalomethyl group (halogen = chlorine or bromine) are smoothly reduced by tri-butyltin hydride to furnish appropriately substituted tropones. Modification of the substituents permits access to a tropolone and to less substituted tropones. The mechanism of this ring expansion process has been discussed.

Structure and biosynthesis of phomenoic acid, an antifungal compound isolated from Phoma lingam Tode

On the basis of 1H and 13C n.m.r. studies, ozonolysis, and biosyntheses from [13C]acetates and [methyl-13C]methionine, structure (1) is proposed for phomenoic acid, an antifungal compound isolated from the mycelium of the fungus Phoma lingam Tode.

Septorine and N-methoxy septorine, substituted pyrazines from the fungus Septoria nodorum berk

Abstract On the basis of 1 H nmr correlations with synthetic analogs, structures 1 and 2 are proposed for septorine and N-methoxy septorine, two p-hydroxybenzoyl 1-isobutyl substituted pyrazines obtained from the fungus Septoria nodorum Berk, a parasite of wheat.

Isolation of the (−)-(3R)-5-hydroxymellein from the fungus Septoria nodorum

Abstract A (−)-(3 R )-5-hydroxymellein (3,4-dihydro-5,8-dihydroxy-(−)-(3 R )-methyl-1H-2-benzopyran-1-one) was isolated from the culture medium of the phytopathogenous fungus Septoria nodorum Berk. This is the first report of this substance from a determined natural source.