Low-abundance kutznerides from Kutzneria sp. 744.
Five new (5-9) and four known (1-4) kutznerides were isolated from the actinomycete Kutzneria sp. 744. Compounds 1-9 all consisted of a cyclohexadepsipeptide core with the general structure 2-(1-methylcyclopropyl)-D-glycine-(2S,3aR,8aS)-6,7-dichloro-3a-hydroxy-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole-2-carboxylic acid-3-hydroxy-D-glutamic acid-O-methyl-L-serine-L-piperazic acid-(S)-2-hydroxy-3,3-dimethylbutyric acid. Compounds 5, 6, and 8 contained erythro-3-hydroxy-D-glutamic acid, whereas 7 and 9 contained the threo isomer and the hydroxy acid was present as (S)-2-hydroxy-3-methylbutyric acid in 5 and 7. The piperazic acid was C-5-N unsaturated and 4-hydroxylated in 6, 4-chlorinated in 8, and C-5-N unsaturated in 9. Minimal inhibitory concentrations for bacteria were found down to 6 microM (Staphylococcus aureus and Erwinia carotovora) and for fungi down to 70 microM (Fusarium culmorum). The trichlorinated 2 and 8 showed the highest antimicrobial activity, whereas 6, with a hydroxylated piperazic acid unit, did not show any inhibition of the pathogens at 230 microM.
Pohanka
Anton
A
Department of Chemistry, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden. Anton.Pohanka@kemi.slu.se
Menkis
Audrius
A
Levenfors
Jolanta
J
Broberg
Anders
A
D039903:Actinobacteria / Q000737:chemistry*; D000890:Anti-Infective Agents / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001232:Aspergillus fumigatus / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D005670:Fusarium / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D016973:Pectobacterium carotovorum / Q000187:drug effects; D010456:Peptides, Cyclic / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D028222:Picea / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D013211:Staphylococcus aureus / Q000187:drug effects
D000890:Anti-Infective Agents; D010456:Peptides, Cyclic