title: Cytotoxic clerodane diterpenoids from the leaves of Polyalthia longifolia.
abstract: The ethanolic extract of Polyalthia longifolia var. pendula was fractionated to get a hexane-soluble residue, which led to the isolation of four clerodane diterpenes: (-)-3α,16α-dihydroxycleroda-4(18),13(14)Z-dien-15,16-olide (1), (-)-3β,16α-dihydroxycleroda-4(18), 13(14)Z-dien-15,16-olide (2), (-)-16α-hydroxycleroda-3,13(14)Z-dien-15,16-olide (3) and (-)-16-oxocleroda-3,13(14)E-dien-15-oic acid (4). Diterpene 1 is a new compound, while 2 is reported for first time from this plant. Both 1 and 2 were tested for their growth inhibitory activity on four cancer cell lines in vitro. IC(50) values suggest that they are effective as cytotoxic agents.
authors.affiliation: Medicinal and Process Chemistry Division, Central Drug Research Institute, Lucknow 226001, India. sashidhar123@gmail.com
authors.forename: Koneni V
authors.initials: KV
authors.lastname: Sashidhara
authors.forename: Suriya P
authors.initials: SP
authors.lastname: Singh
authors.forename: Jayanta
authors.initials: J
authors.lastname: Sarkar
authors.forename: Sudhir
authors.initials: S
authors.lastname: Sinha
mesh_terms: D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D045785:Diterpenes, Clerodane / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007194:India; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D010936:Plant Extracts / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D031044:Polyalthia / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D045785:Diterpenes, Clerodane; D010936:Plant Extracts; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue