Polyclinal,a new sulfated polyhydroxy benzaldehyde from the marine ascidianPolyclinum planum

Summary A new sulfated polyhydroxy benzaldehyde has been isolated from extracts of the temperate colonial ascidianPolyclinum planum. The structure of the new metabolite was solved by an X-ray crystallographic study. The highest concentration of this metabolite was found in the zooid-rich outer layers of this ascidian suggesting that it may represent a potential chemical defense against predators.     

Fijiensin,the first phytotoxin fromMycosphaerella fijiensis,the causative agent of Black Sigatoka disease

Summary Fijiensin, a novel phytotoxic metabolite, was isolated from a culture of the fungusMycosphaerella fijiensis, the causal agent of Black Sigatoka disease of banana. Fijiensin is phytotoxic on various banana cultivars, but not toward non-host plants. The structure of fijiensin was determined by X-ray analysis.     

Production de nidulotoxine par desAspergillus appartenant à différentes espèces

Summary Strains ofA. versicolor Tiraboshi andA. Sydowi Thorn and Church produce a toxic metabolite spectrographically identical with the nidulotoxin.     

Neoechinulin D,a new isoprenylated dehydrotryptophyl metabolite fromAspergillus amstelodami

Summary Isolation and structural determination of a novel isoprenylated dehydrotryptophyl metabolite fromAspergillus amstelodami, neoechinulin D, is reported.     

Konstitution des Rifamycins B und verwandter Rifamycine

Summary Constitution I, based on extensive degradation studies, is proposed for Rifamycin B, a metabolite ofstreptomyces mediterraneus n. sp.     

The identification of norlobariol,a new lichen constituent fromXanthoparmelia scabrosa (Tayl.) Hale

Summary Norlobariol (I) previously described as a synthetic product derived from norlobaridone (II) was isolated as a new metabolite fromXanthoparmelia scabrosa (Tayl.) Hale.Acknowledgment. The authors wish to acknowledge the assistance of Dr D. Galloway in identifying the lichen sample and Dr A.W. Campbell for the microanalytical data.     

Biotransformation of a dietary sesterterpenoid in the Mediterranean nudibranchHypselodoris orsini

The metabolic relationship between the marine molluscHypselodoris orsini and the spongeCacospongia mollior has been reinvestigated. The predator-prey association has been confirmed even though the metabolic patterns of the two invertebrates are substantially different. Most probably the nudibranch converts the main sponge metabolite, the sesterterpenoid scalaradial (1), into a less oxygenated related metabolite, deoxoscalarin (4), followed by a second chemical transformation leading to a new sesterterpenoid, 6-keto-deoxoscalarin (5) which is selectively compartmentalized into some dorsal glands, mantle dermal formations (MDFs), strategically distributed near the gills. 6-keto-deoxoscalarin (5) has been characterized by 1D and 2D NMR methods. Finally, the unusual association of some Chromodorididae molluscs with sponges containing sesterterpenoids suggests a further analysis of their taxonomical collocation is required.     

Rifamycin Y und seine Umwandlungsprodukte

Summary The constitution I has been determined for rifamycin YO. The compound is an oxidation product of rifamycin Y, a metabolite ofStreptomyces mediterranei n. sp.     

Role of fungal statling growth products in inter-specific competition among phylloplane fungi

Summary The effect of fungal staling growth products on leaf-inhabiting microfungi, with special reference to a leaf spot pathogenPestalotiopsis funerea Desm. ofEucalyptus globulus Labill. was studied. Results depict that antibiotics produced by competing microfungi caused the phenomenon of mycostasis on the leaf surfaces.Acknowledgments. I would like to express my thanks to Professor R.S. Dwivedi for his encouragement and to CSIR (Indian Govt.) for financial assistance.     

A convenient thin layer chromatographic method for the detection of cyclochlorotine and simatoxin,toxins fromPenicillium islandicum Sopp

Summary A rapid, convenient TLC method is described for detection of cyclochlorotine, a carcinogen produced by the commonly found storage moldPenicillium islandicum Sopp. This method has also led to the isolation of a new toxic metabolite, simatoxin.Acknowledgment. This work was supported by Food and Drug Administration, Washington, D.C. (Contract No. FDA-223-74-2209).     

Toxic substances produced byFusarium VI. Anti-F. oxysporum f. sp.carthami effect of 2,2′,4-trihydroxybenzophenone

Summary Anti-Fusarium oxysporum f. sp.carthami activity of 2,2,4-tri-hydroxybenzophenone was evaluated. Pretreatment with the benzophenone offered complete protection to safflower seeds and seedlings, and recovery of the latter from the fungal infection.     

Role of toxins in evolution and ecology of plant pathogenic fungi

Many fungal pathogens of plants adapt readily to changes in agriculture. Among the most revealing is a fungal group whose species produce host-selective toxins as key determinants of disease. Several lines of evidence support the hypothesis that these fungi evolved from opportunistic, low-grade pathogens by gaining new genetic information leading to toxin production; in some species, toxin production is known to be under single gene control. as a result of this evolution, these fungi became virulent and host-specialized. The best-known model cases belong to the generaCochliobolus andAlternaria; there are suggestions of evolutionary lines among these genera, with species that range from saprophytes to opportunists to specialized pathogens. Host specialization can lead to genetic isolation, a first step in speciation. Ability to produce host-selective toxin has allowed these fungi to exploit the monocultures and genetic uniformity of modern agriculture. Destructive epidemics have been the result.     

Effect of volatile phylloplane fungal metabolites on the growth of a foliar pathogen

Summary Volatile fungal metabolites excluded from various leaf-inhabiting microfungi were tested for their mycostatic activity against the growth ofPestalotiopsis funerea Desm., a leaf spot pathogen ofEucalyptus globulus Labill. Findings reveal thatTrichoderma viride andTrichothecium roseum exhibited significant antagonistic action, however,Cladosporium herbarum, Nigrospora sphaerica andPapulaspora sp. showed a stimulating effect. A morphophysiological effect was also observed.Acknowledgments. The grant from CSIR (India Govt.) in the form of SRF and laboratory facility from the Department of Botany, Banaras Hindu University are gratefully acknowledged. Thanks are due to Professor R.S. Dwivedi for guidance and constant encouragements.     

Isolation of indole-3-acetic acid methyl ester,a metabolite of indole-3-acetic acid fromPseudomonas amygdali

From the culture filtrates ofPseudomonas amygdali the methyl ester of indole-3-acetic acid (IAA), a product of indole-3-acetic acid metabolism which has the same auxin activity as the free acid, has been isolated. This is the first report of its occurrence as a microbial metabolite.     

Isolation of (−)-cryptosporiopsin,a chlorinated cyclopentenone fungitoxic metabolite fromPhialophora asteris f. sp.helianthi

Summary The (–)-enantiomer of cryptosporiopsin, a chlorinated cyclopentenone fungitoxic metabolite, was isolated fromPhialophora asteris f. sp.helianthi. Next to a comparable fungitoxic activity as shown by crypstosporiopsin, the product particularly inhibits growth ofSclerotinia sclerotiorum, an important pathogen on sunflower. Two further metabolites were tentatively identified as a stereoisomer of cryptosporiopsin and its dehydrated derivative.The authors are much indebted to Dr.G. M. Strunz (Canadian Forestry Service) for valuable suggestions and the generous gift of cryptosporiopsin and to the University of Utrecht for the part-time fellowship to one of us (Y.T.) given.     

In vitro metabolism of the trichothecene 4-monoacetoxyscirpenol by fungus- and non-fungus-feeding insects

Summary The metabolism of the trichothecene 4-monoacetoxyscirpenol by intact gut tissue was determined in the fungus-feeding Nitidulid,Carpophilus hemipterus (L.) and the non-fungus-feeding caterpillars, the fall armyworm,Spodoptera frugiperda (J. E. Smith) and the corn earworm,Heliothis zea (Boddie). The primary metabolite was the hydrolysis product scirpentriol. The amount of metabolism by theC. hemipterus larvae was ca 10 times that of the caterpillars on a per mg protein basis, suggesting metabolic adaptation for feeding on fungi that may contain mycotoxins.Acknowledgment. The authors wish to thank S. Taylor for technical assistance.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Identification of mucondialdehyde as a novel stress metabolite

In a survey of antifungal stress compounds induced by cupric chloride we found that leaves ofChenopodium album exuded a highly fungitoxic metabolite mucondialdehyde (trans-2,trans-4-hexadienedial), which was associated with 13-oxo-9,11-tridecadienoic acids (cis-9,trans-11 andtrans-9,trans-11 isomers) presumably resulting from -scission of 13-hydroperoxy-octadecadi(tri)enoic acid. The biogenesis and role as a general defensive agent in plants are briefly discussed.     

Temporal storage of kynurenine and 3-OH-kynurenine in the fat body of metamorphosingEphestia kühniella

Summary During the pharate pupal stage a massive accumulation of kynurenine and 3-OH-kynurenine is observed in the fat body ofEphestia kühniella. By injection it can be demonstrated that this organ is capable of sequestering at least 3-OH-kynurenine, the dominating tryptophan metabolite inEphestia. It is suggested that the fat body reduces a possibly harmfull excess of tryptophan metabolites at the beginning of metamorphosis. These sequestered metabolites provide a precursor depot for ommochrome synthesis in later development.     

Laccase production byPolyporus sanguineus under different nutritional and environmental conditions

Summary Laccase production was higher in malt extract medium than in lignin, andPolyporus sanguineus appears to be better thanPolyporus versicolor andTrametes hirsuta (syn.Polyporus hirsutus) for enzyme production. Phenolic compounds, of which resorcinol was the most active, induced enzyme production; while sugars repressed it. A temperature of 37°C, pH 3 and indulin AT at a concentration of 0.2% gave the best enzyme yield.A part of Ph. D. thesis of D.S. Arora.Acknowledgments. We thank Westvaco Chemical Division, USA, and Dr P.S. Rehill, Forest Research Institute, Dehradun, India for providing lignin samples and the fungal strain, respectively. D.S. Arora further thanks University Grants Commission, New Delhi for financial assistance.     

Metabolism of C19-steroids in testicular tissue of the newtTriturus vulgaris,during and after breeding

Summary Incubation studies with testicular homogenates ofTriturus vulgaris showed that testosterone was quantitatively the most important metabolite of dehydroepiandrosterone and androstenedione during breeding. After breeding the recovery of testosterone declined. This suggests that 17-hydroxysteroid dehydrogenase may be regulated for the needs of testicular androgen production.