Stoffwechselprodukte von Mikroorganismen 73. Mitteilung [1] Chlorothricin und Des‐chlorothoricin

Abstract

A crystalline mixture of the antibiotics chlorothricin and dechlorothricin was isolated from a strain of Streptomyces antibioticus. By degradation 5‐chloro‐6‐methylsalicylic acid methyl ether (from chlorothricin) and 6‐methylsalicylic acid methyl‐ether (from dechlorothricin) were isolated. Common degradation products of both antibiotics were 2‐deoxy‐D‐rhamniose and an aglycone, C30H38O8, of unknown structure. The antibiotic mixtures was active against GRAM positive bacteria on syntheitc, but not on complex media.

Natural [4 + 2]-Cyclases

“…155–157 A subclass of this family of natural products has drawn particular interest, because the tetronate or tetramate namesake appears to have undergone an intramolecular Diels-Alder reaction with a 1,3-diene to form a cyclohexene ring with a tertiary carbon joint. 12,157 Examples of such spirotetronates and spirotetramates are shown in Figure 6 and include versipelostatin ( 74 ), 158–161 pyrroindomycin ( 75 ), 162–166 chlorothricin ( 76 ), 167–175 kijanimicin ( 77 ), 176–181 the quartromicins ( 78 ), 182–186 the abyssomicins ( 79 ), 187–192 tetrocarcin, 193–198 the lobophorins, 199–205 nomimicin, 206 maklamicin, 207–209 and tetronothiodin. 210–214 Furthermore, several of these compounds also possess a second, decalin ring system, the formation of which is highly reminiscent of the reactions catalyzed by LovB and solanapyrone synthase (see above).…”

Spirotetronate Polyketides as Leads in Drug Discovery

“…The search for new antitumor antibiotics led to the discovery of chlorothricin ( 1 ), a complex polyketide produced by various Streptomyces strains. 6 Its intriguing chemical structure and bioactivity defined a new family of microbial metabolites, commonly referred to as spirotetronate polyketides. This family is identified by the presence of a cyclohexene ring spiro-linked to a tetronic acid moiety (Figure 1 , fragment A) that is embedded in a macrocycle (Figure 1 , fragment B).…”

Marine Spirotetronates: Biosynthetic Edifices That Inspire Drug Discovery

“…The discovery of chlorothricin ( 1 ) in 1969 [38] defined a new class of bacterial metabolites that possess an architecturally intriguing structure and promising chemotherapeutic properties as antitumor antibiotics. Referred to as spirotetronates, these compounds are commonly produced by both marine and terrestrial actinomyces and are structurally identified by the presence of a tetronic acid spiro-linked to a cyclohexene (or a cyclohexane) ring (Figure 1b, red motif).…”