title: Antimicrobial activity of sesquiterpene lactones isolated from traditional medicinal plant, Costus speciosus (Koen ex.Retz.) Sm.
abstract: BACKGROUND
  Costus speciosus (Koen ex.Retz.) Sm (Costaceae) is an Indian ornamental plant which has long been used medicinally in traditional systems of medicine. The plant has been found to possess diverse pharmacological activities. Rhizomes are used to treat pneumonia, rheumatism, dropsy, urinary diseases, jaundice, skin diseases and leaves are used to treat mental disorders.
  
  
  METHODS
  Antibacterial and antifungal activities were tested using Disc diffusion method and Minimum Inhibitory Concentration (MIC). Column chromatography was used to isolate compounds from hexane extract. X-ray crystallography technique and GC-MS analysis were used to identify the compounds
  
  
  RESULTS
  Antibacterial and antifungal activities were observed in hexane, chloroform, ethyl acetate and methanol extracts. Hexane extract of C.speciosus showed good activity against tested fungi also. Two sesquiterpenoid compounds were isolated (costunolide and eremanthin) from the hexane extract. Both the compounds did not inhibit the growth of tested bacteria. But, both the compounds inhibited the tested fungi. The compound costunolide showed significant antifungal activity. The MIC values of costunolide were; 62.5 μg/ml against Trichophyton mentagrophytes, 62. μg/ml against T. simii, 31.25 μg/ml against T. rubrum 296, 62.5 μg/ml against T. rubrum 57, 125 μg/ml against Epidermophyton floccosum, 250 μg/ml against Scopulariopsis sp, 250 μg/ml against Aspergillus niger, 125 μg/ml against Curvulari lunata, 250 μg/ml against Magnaporthe grisea.
  
  
  CONCLUSIONS
  Hexane extract showed promising antibacterial and antifungal activity. The isolated compound costunolide showed good antifungal activity.
authors.affiliation: Department of Botany and Microbiology, Addiriyah Chair for Environmental Studies, College of Science, King Saud University, Riyad, Saudi Arabia.
authors.forename: Veeramuthu
authors.initials: V
authors.lastname: Duraipandiyan
authors.forename: Naif Abdullah
authors.initials: NA
authors.lastname: Al-Harbi
authors.forename: Savarimuthu
authors.initials: S
authors.lastname: Ignacimuthu
authors.forename: Chinnasamy
authors.initials: C
authors.lastname: Muthukumar
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D029770:Costus / Q000737:chemistry*; D005658:Fungi / Q000187:drug effects*; D007783:Lactones / Q000302:isolation & purification / Q000494:pharmacology*; D008519:Medicine, Traditional; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D012717:Sesquiterpenes / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D007783:Lactones; D010936:Plant Extracts; D012717:Sesquiterpenes; C002601:eremanthin; C002602:costunolide