title: Sesquiterpenes from Oplopanax horridus.
abstract: From the anti-TB active fractions of the inner stem bark of Oplopanax horridus, two new heterocyclic nerolidol derivatives, 3,10-epoxy-3,7,11-trimethyldodeca-1,6-dien-11-ol, named neroplomacrol (1), and rel-(3S,6R,7S,10R)-7,10-epoxy-3,7,11-trimethyldodec-1-ene-3,6,11-triol, named neroplofurol (2), were isolated together with oplopandiol (3), falcarindiol (4), and sesamin (5). Extensive spectroscopic analysis revealed that 1 possesses a novel 3,10-oxanonacyclic ring system. Computer-iterated full spin system analysis led to the generation of (1)H NMR fingerprints that will facilitate future dereplication of analogues by providing characteristic spin-spin coupling patterns. The full spin analysis of 5 revealed asymmetric coupling patterns among the chemically equivalent spins, thus confirming the magnetic asymmetry of 5. It was further demonstrated that (1)H NMR fingerprints and MS data enable dereplication of isolates at a submilligram levels including their relative configuration. Countercurrent concentration of the anti-TB activity of the ethnobotanical O. horridus versus the Mycobacterium tuberculosis Erdman strain led to polyynes 3 and 4 as main anti-TB active principles. Their synergistic behavior is linked to a complex fraction containing the new nerolidiol sesquiterpenes, 1 and 2, as phytochemical marker compounds.
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy and Institute for Tuberculosis Research, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
authors.forename: Taichi
authors.initials: T
authors.lastname: Inui
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Wang
authors.forename: Dejan
authors.initials: D
authors.lastname: Nikolic
authors.forename: David C
authors.initials: DC
authors.lastname: Smith
authors.forename: Scott G
authors.initials: SG
authors.lastname: Franzblau
authors.forename: Guido F
authors.initials: GF
authors.lastname: Pauli
mesh_terms: D000413:Alaska; D000995:Antitubercular Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D019906:Nuclear Magnetic Resonance, Biomolecular; D028002:Oplopanax / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: C549653:3,10-epoxy-3,7,11-trimethyldodeca-1,6-dien-11-ol, named neroplomacrol; D000995:Antitubercular Agents; D012717:Sesquiterpenes; C549652:rel-(3S,6R,7S,10R)-7,10-epoxy-3,7,11-trimethyldodec-1-ene-3,6,11-triol; C037055:nerolidol