ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A colourless, crystalline metabolite, C14H12ClNO4, named streptopyrrole, has been isolated from submerged fermentation cultures of Streptomyces armeniacus by extraction, followed by chromatographic purification. Its tricyclic molecular framework, seemingly without natural product precedents. as well as its substitution pattern were derived from extensive NMR analysis including H-1-detected INADEQUATE experiments. Streptopyrrole exhibits weak growth inhibitory effect towards a broad range of microorganisms.

In screening for antifungal metabolites a novel compound, cladobotryal, was isolated from the mycoparasitic fungus Cladobotryum varium. Its structure was established as (+)-(2R*,3R*)-2-[(Z)-2-buten-2-yl]-3, 7-dihydro-3-formyl-3-methyl-5-phenylfuro[2,3-b]pyridin-4(2H)-one on the basis of spectroscopic evidence and single crystal X-ray analysis of its methyl hemiacetal. The fused furo[2,3-b]pyridinone skeleton of cladobotryal seems unprecedented within the chemical literature.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

As part of a screening programme a new antifungal substance, hypomycetin, has been isolated from the mycophilic fungus Hypomyces aurantius. Its tetracyclic structure, including the absolute configuration, has been established by spectroscopic methods and CD measurements. The biosynthetic pathway to hypomycetin has been unveiled by feeding experiments with C-13-labelled precursors, followed by extensive NMR analyses. The extent of its relationship to viridicatumtoxin, a known, structurally similar fungal metabolite, and to the tetracyclic Streptomyces antibiotics, such as tetracycline and various congeners, is discussed in terms of biosynthetic origins. A polyketide folding mode, different from that involved in the biosynthesis of the tetracyclines, has been documented as the starting point on the path to hypomycetin.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

In screening for antifungal metabolites, a novel compound, malonofungin, exhibiting growth inhibitory activity against Botrytis cinerea (grey mould), has been isolated from fermentations of Phaeoramularia fusimaculans CBS 616.87. Its structure is established as (E)-(3R,4S,5S)-5-acetoxy-2-amino-2-carboxy-3,4-dihydroxy-14-oxoicos++ +-6-enoic acid, representing an addition to the rare class of naturally occurring aminomalonic acids. 1H NMR data and extensive use of CD spectroscopy have been utilized to establish the absolute stereochemistry of malonofungin. The structural and biological relationship of malonofungin to previously reported fungal metabolites is discussed.

During ongoing screening for antifungal metabolites of potential interest for agricultural applications, an unidentified species of Fusicoccum (IMI CC No. 351573), isolated from Mediterranean plant material, was discovered as an efficient source of a novel tetronic acid, xanthofusin (is-3,4-dihydroxy-2-methyl-6-oxo-2,4-heptadienoic acid-y-lactone), which exhibited interesting antifungal activities.We report on its production, isolation, chemical structure and biological activity.Characterization of Fusicoccum sp.IMI CC No. 351573 Symptom-bearing plant material of the Lilliaceae, Ashodelus macrocarpus, was collected July 1991 in Greece.After surface sterilization, small segments of stem, leaf and fruit were plated on Potato Dextrose Agar (PDA, Difco) plates and incubated for 2 days at 26°C.Pure cultures could be obtained from the plates by one additional transfer to PDA plates.The culture was maintained on PDAslants and deposited with the International Mycological Institute Culture Collection, Kew, England (IMI CC No. 351573).The characteristics of a three day old colony are a whitish outer zone, made up of young transparent hyphae, a darker inner zone, and a center with pycnidia.The dark zone is made up of coarse, wavy, pigmented hyphae.The pycnidia mature and ooze with conidia after three days of incubation at 26°C.The pycnidia are cream colored, often irregular in

This chapter contains sections titled: Introduction Nomenclature History Analogues of Alcohols and Ethers Onium Salts and Ylides Insertion Compounds Analogues of Sulphoxides, Sulphones and Related Compounds Analogues of Carbonyl Compounds OXO Acids of Sulphur, Selenium and Tellurium Halogen Compounds Chalcogen Derivatives of Group V Elements Heterocyclic Compounds References

AbstractThe structure of boronolide (I) is established to be (6R, l ′R,2′R,3′S) by means of X‐ray diffraction analysis.

Glucosinolates (β-thioglucoside-N-hydroxysulfates), the precursors of isothiocyanates, are present in sixteen families of dicotyledonous angiosperms including a large number of edible species. At least 120 different glucosinolates have been identified in these plants, although closely related taxonomic groups typically contain only a small number of such compounds. Glucosinolates and/or their breakdown products have long been known for their fungicidal, bacteriocidal, nematocidal and allelopathic properties and have recently attracted intense research interest because of their cancer chemoprotective attributes. Numerous reviews have addressed the occurrence of glucosinolates in vegetables, primarily the family Brassicaceae (syn. Cruciferae; including Brassica spp and Raphanus spp). The major focus of much previous research has been on the negative aspects of these compounds because of the prevalence of certain “antinutritional” or goitrogenic glucosinolates in the protein-rich defatted meal from widely grown oilseed crops and in some domesticated vegetable crops. There is, however, an opposite and positive side of this picture represented by the therapeutic and prophylactic properties of other “nutritional” or “functional” glucosinolates. This review addresses the complex array of these biologically active and chemically diverse compounds many of which have been identified during the past three decades in other families. In addition to the Brassica vegetables, these glucosinolates have been found in hundreds of species, many of which are edible or could provide substantial quantities of glucosinolates for isolation, for biological evaluation, and potential application as chemoprotective or other dietary or pharmacological agents.

Sulphur, besides being an integral element of several macromolecular cell constituents, appears in a series of low-molecular weight, partly ubiquitously distributed compounds, e. g. S-containing protein amino acids, coenzyme A, S-adenosyl methionine, thiamine, and biotin, without which a steady state of living cells cannot be maintained. These, however, are not included in the present discussion. Rather, an attempt is being made to illustrate, by way of examples, the vast structural variation in other organic sulphur compounds with, as far as we know, a discontinuous distribution within the plant and animal kingdom. The chemical characteristics of these compounds are variegated, encompassing, inter alia, mercaptans, thiolesters, disulphides, sulphides (linear, cyclic, aromatic, and heterocyclic), amino acids, thioglycosides, terpenoids, sulphoxides, sulphones, and sulphates, the origin, transformations, and biological importance of which are mostly unknown. A bird's-eye view of the area is presented in the hope that this, however incomplete and blurred, may reveal some less obvious relationships and thus serve to invigorate further activity within the field.

AbstractDie Hydroximate (I)/(II) wurden nach bekannten Methoden dargestellt.

AbstractBei 4stündiger Behandlung von Sulphoraphen (III) mit methanolischem Ammoniak entsteht der Thioharnstoff (Ia).