Aus der Nahrlosung des Pilzes Botrytis cinefeu wurden das antibiotisch wirksame Botrydial (3) und sein Dihydroderivat (1) isoliert. Durch eine Folge chemischer Umwandlungcn, verbunden mit der Anwendung spektroskopischer Methoden, insbesondere einer detaillierten Analyse der NMR-Spektren. wurden ihre Konstitutionsformeln abgeleitet. Botrydial liegt ein bicyclisch nicht-isoprenoides Sesquiterpenskelett zugrundc. Botrydial, a Sesquiterpene Antibiotic from the Culture Solution of the Fungus Borrytis cinereuThe antibiotic botrydial (3) and its dihydro derivative (1) were isolated from the culture solution of the fungus Borrytis cinefeu. Their structural formulas were elucidated by means of a series of chemical transformations together with the application of spectroscopic methods, especially a detailed analysis of the n.m.r. spectra. The basic skeleton of botrydial is a bicyclic, non-isoprenoid sesquiterpene system. wurde uber einen aus dem Griffel einer Fuchsie isolierten Stamm des PilzesBorrytis cinerea berichtet, der in Biomalz-Nahrlosung ein Antibiotikum mit fungistatischer und antibakterieller (bei Gram-positiven Keimen) Wirkung bildet4). Die Erzeugung des Wirkstoffs, der rnit Lipoidlosungsmitteln extrahierbar ist, unterliegt allerdings starken Schwankungen4). Uns interessierte nun, die chemische Natur dieser Verbindung aufzukliiren.Durch Chromatographie eines aus der Nahrlosung gewonnenen Benzolextrakts an desaktiviertern Kieselgel lieBen sich zwei kristalline Verbindungen isolieren: Je Liter Nahrlosung erhielt man ca. 10 rng antibiotisch wirksames Material und etwa 80 mg unwirksame Dihydrokomponente. Aufgrund der irn folgenden beschriebenen chemischen und spektroskopischen Untersuchungen kommt dem Antibiotikum die Struktur des tetrafunktionellen Sesquiterpens 3 zu; da es zwei Aldehydgruppen besitzt, schlagen wir die Bezeichnung Botrydiul vor.

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Effects of arbuscular mycorrhizal (AM) symbiosis on health of Linum usitatissimum infected by fungal pathogens were investigated exemplarily. Physiological and biochemical analyses were done to explain the mechanisms underlying the AM effects. AM plants showed increased resistance against the wilt pathogen (Fusarium oxysporum f. sp. lini), the level of this effects depended on the plant cultivars which all showed the same level of root colonization by arbuscular mycorrhizal fungi (AMF). In contrary to that, AM plants were highly susceptible against the shoot pathogen Oidium lini, but they suffered less than non-AM plants in terms of shoot fresh weight, CO2 assimilation and content of sucrose in shoot apex. This indicates that AM not only activates resistance mechanisms but also can induce tolerance against pathogens. The concentration of phytohormones such as auxin-and gibberellin-like substances were increased in shoots of AM plants. In roots the ethylene production was increased, too. Furthermore the content and composition of free sterols were highly altered in leaves of AM plants. Root infection by AMF caused an increased respiratory activity and a reduced degree of DNA methylation, but both modifications only occurred in infected root parts indicating an increasing gene activity. The presented results suggest that nearly all parts of a plant are influenced by AM but not in the same manner. In the case of mildewed linseed the effect of AM on plant health was impressing, it indicates that AM has an ability to induce tolerance.

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