title: Helquinoline, a new tetrahydroquinoline antibiotic from Janibacter limosus Hel 1+.
abstract: The ethyl acetate extract of cultures of Janibacter limosus showed a high biological activity against bacteria, and fungi and delivered two new natural products, a tetrahydroquinoline derivative designated as helquinoline (1), and the N-acetylkynuramine (3a), along with other known secondary metabolites. The structure of 1 has been elucidated as 4-methoxy-2-methyl-1,2,3,4-tetrahydroquinoline-8-carboxylic acid on the basis of 1D and 2D NMR and mass spectra. The relative stereochemistry of the compound 1 was assigned as 2R*,4R* with the aid of coupling constants, NOESY correlation and by comparison with a related compound.
authors.affiliation: Department of Organic Chemistry, University of Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany.
authors.forename: Ratnakar N
authors.initials: RN
authors.lastname: Asolkar
authors.forename: Dirk
authors.initials: D
authors.lastname: Schröder
authors.forename: Rolf
authors.initials: R
authors.lastname: Heckmann
authors.forename: Siegmund
authors.initials: S
authors.lastname: Lang
authors.forename: Irene
authors.initials: I
authors.lastname: Wagner-Döbler
authors.forename: Hartmut
authors.initials: H
authors.lastname: Laatsch
mesh_terms: D000192:Actinomycetales / Q000737:chemistry / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005285:Fermentation; D007735:Kynuramine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011804:Quinolines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
chemical_list: D000900:Anti-Bacterial Agents; D011804:Quinolines; D007735:Kynuramine