title: Antitubercular constituents of Valeriana laxiflora.
abstract: Antitubercular bioassay-guided fractionation of the n-hexane- and CH (2)Cl (2)-soluble extracts of the above-ground biomass and roots of Valeriana laxiflora led to the isolation of a new iridolactone, (4R,5R,7S,8S,9S)-7-hydroxy-8-hydroxymethyl-4-methyl-perhydrocyclopenta[ c]pyran-1-one ( 1), and a new lignan, (+)-1-hydroxy-2,6-bis- epi-pinoresinol ( 2), along with eleven known compounds, betulin ( 3), betulinic acid ( 4), 5,7-dihydroxy-3,6,4'-trimethoxyflavone ( 5), 23-hydroxyursolic acid ( 6), oleanolic acid ( 7), tricin ( 8), ursolic acid ( 9), ferulic acid, (+)-1-hydroxypinoresinol, prinsepiol, and 5,7,3'-trihydroxy-4'-methoxyflavone. The structures of compounds 1 and 2 were elucidated on the basis of spectroscopic evidence. The absolute stereochemistry of 1 was determined by chemical transformations and Mosher ester procedures. In a microplate alamar blue assay against Mycobacterium tuberculosis, compounds 2 - 9 exhibited minimum inhibitory concentrations (MIC) of 15.5 - 127 microg/mL, while the other isolates were regarded as inactive (MIC > 128 microg/mL). In addition, all the isolates were tested for cytotoxicity against African green monkey Vero cells in order to evaluate their selectivity potential.
authors.affiliation: Department of Pharmacology and Toxicology, Division of Medicinal and Natural Products Chemistry, College of Pharmacy, University of Arizona, 1703 E. Mabel Street, Tucson, AZ 85721, USA.
authors.forename: Jian-Qiao
authors.initials: JQ
authors.lastname: Gu
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Wang
authors.forename: Scott G
authors.initials: SG
authors.lastname: Franzblau
authors.forename: Gloria
authors.initials: G
authors.lastname: Montenegro
authors.forename: Danzhou
authors.initials: D
authors.lastname: Yang
authors.forename: Barbara N
authors.initials: BN
authors.lastname: Timmermann
mesh_terms: D000818:Animals; D000995:Antitubercular Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D002522:Chlorocebus aethiops; D006801:Humans; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D028161:Valerianaceae; D014709:Vero Cells / Q000187:drug effects
chemical_list: D000995:Antitubercular Agents; D010936:Plant Extracts