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Salmycin A–D, Antibiotics from Strep tomy ces violaceus, DSM 8286, Having a Siderophor‐Aminoglycoside Structure Salmycin B (2) and C (3) were isolated under acid conditions, under which they are stable, from the culture broth of Streptomyces violaceus, DSM 8286. The acid‐ and alkaline‐labile, native main component salmycin A (1), as well as salmycin D (4), were obtained under strictly neutral pH conditions. The compounds 1 (C41H70FeN7O21), 2 (C41H69FeN6O21), 3 (C40H67FeN6O21), and 4 (C40H68FeN7O21) are classified as sideromycins and are stable when dry. Mild alkaline hydrolysis of 1 and 2 yielded the known siderophor danoxamin (5; C27H46FeN5O11), and amino‐disaccharides. The amino‐glycoside 6 (C14H25NO11) of salmycin B was stabilized by hydrogenation and the structure of the corresponding peracetate 10 determined by 1H,1H‐ and 1H,13C‐correlation NMR spectroscopy (Table 1). Compound 6 consists of a glucos‐2‐ulose unit which is linked to the 2‐position of a 6‐deoxy‐6‐(methylamino)heptopyranose. The danoxamin is bonded via the carboxy group by ester linkage to the primary alcohol of the glucos‐2‐ulose. Salmycin A (1) is a natural oxime of 2, it was synthesized from 2 with hydroxylamine. The salmycins and those derivatives which contain hexapyranos‐2‐ulose form stable ketone hydrates which can be identified by mass spectrometry. Although several recently identified features of the danomycins do not correspond with those of the salmycins, 13C‐NMR spectra show that both groups of antibiotics are closely related. All salmycins, especially component 1, are highly active against Staphylococci and Streptococci, even against resistant strains of these pathogens.

Mersacidin (1) is a new peptide antibiotic containing /?-methyllanthionine. It is classified as a memberof the proposed lantibiotic group of antibiotics, and is produced by a species of Bacillus. Mersacidin has a molecular weight of 1,824 (C80H120N20O21S4). The antibiotic is active against Gram-positive organisms including methicillin-resistant Staphylococcus aureus, but has no activity against Gram-negative bacteria or fungi.

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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