title: A new labdane diterpene from Vitex negundo.
abstract: BACKGROUND
  Vitex negundo Linn. (Verbenaceae) seeds are pepper substitute and occasionally used as a condiment for edible purposes. The seeds also find use for analgesia, sedation, rheumatism and joint inflammation in folk medicine.
  
  
  OBJECTIVE
  To isolate and characterize bioactive constituents from V. negundo seeds.
  
  
  METHODS
  The ethanol extract of V. negundo seeds was subjected to repeated column chromatography. Chemical structures were elucidated by detailed spectroscopic analyses on the basis of NMR, IR, and MS data. Several pathogenic fungi isolates were employed to evaluate the antifungal activity of the isolated compound.
  
  
  RESULTS
  Chemical investigations of the seed extract afforded a new labdane diterpenoid, named negundol (1a + 1b), as an inseparable mixture of two diastereoisomers in a 5:4 ratio. Their structures were identified as (rel 3S, 5S, 8R, 9R, 10S, 13S, 16S)-3-acetoxy-9, 13-epoxy-16-hydroxy-labda-15, 16-olide (1a), and (rel 3S, 5S, 8R, 9R, 10S, 13S, 16R)-3-acetoxy-9, 13-epoxy-16-hydroxy-labda-15, 16-olide (1b). Compound 1 was active as an antifungal agent with MIC₈₀ values in the range of 16-64 μg/mL.
  
  
  CONCLUSIONS
  The presence of compound 1 in V. negundo is of chemotaxonomic significance, since plants under the genus Vitex are chemically characterized with labdane diterpenoids. Compound 1 exhibited potential antifungal activity and may be considered a lead compound for promising antifungal agent.
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Second Military Medical University, Shanghai, PR China.
authors.forename: Cheng-Jian
authors.initials: CJ
authors.lastname: Zheng
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: Lan
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Bao-Kang
authors.initials: BK
authors.lastname: Huang
authors.forename: Ting
authors.initials: T
authors.lastname: Han
authors.forename: Qiao-Yan
authors.initials: QY
authors.lastname: Zhang
authors.forename: Lu-Ping
authors.initials: LP
authors.lastname: Qin
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001232:Aspergillus fumigatus / Q000187:drug effects*; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D055808:Drug Discovery; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D012639:Seeds / Q000737:chemistry*; D013237:Stereoisomerism; D020950:Vitex / Q000737:chemistry*; D015003:Yeasts / Q000187:drug effects*
chemical_list: C575066:3-acetoxy-9,13-epoxy-16-hydroxylabda-15,16-olide; D000894:Anti-Inflammatory Agents, Non-Steroidal; D000935:Antifungal Agents; D004224:Diterpenes; D004365:Drugs, Chinese Herbal