title: Clethramycin, a new inhibitor of pollen tube growth with antifungal activity from Streptomyces hygroscopicus TP-A0623. I. Screening, taxonomy, fermentation, isolation and biological properties.
abstract: The cytoskeletal proteins, actin and myosin, play a central role in pollen tube growth. The pollen tube growth is inhibited by cytochalasin, which interferes with actin polymerization. In the screening of pollen tube growth inhibitors, clethramycin was found from the fermentation broth of an actinomycete strain TP-A0623. The producing strain was isolated from a root of Clethra barbinervis collected in Toyama, Japan and identified as Streptomyces hygroscopicus based on the taxonomic study. Clethramycin showed in vitro antifungal activity against yeast such as Candida albicans and C. glabrata with the MIC of 0.5 approximately 8 microg/ml, but weak activity against Gram-positive and negative bacteria (MIC > or = 64 microg/ml). Cytotoxicity of clethramycin was moderate and the IC50 was 57 microg/ml against HeLa cells and 120 microg/ml against WI-38 cells.
authors.affiliation: Biotechnology Research Center, Toyama Prefectural University, 5180, Kurokawa, Kosugi, Toyama 939-0398, Japan. furumai@pu-toyama.ac.jp
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Furumai
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamakawa
authors.forename: Ryuji
authors.initials: R
authors.lastname: Yoshida
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Igarashi
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005285:Fermentation; D035264:Flowers / Q000187:drug effects / Q000254:growth & development; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008826:Microbial Sensitivity Tests; D013302:Streptomyces; D013463:Sulfuric Acid Esters / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D005231:Fatty Acids, Unsaturated; D013463:Sulfuric Acid Esters; C478490:clethramycin