title: New bioactive clerodane diterpenoids from the bark of Casearia grewiifolia.
abstract: Bioactivity-guided fractionation of hexane and dichloromethane extracts of the bark of Casearia grewiifolia afforded four new clerodane diterpenes, caseargrewiins A-D (1-4), and two known clerodane diterpenes, rel-(2S,5R,6R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-6-methoxy-2-(2-methylbutanoyloxy)cleroda-3,13(16),14-triene (5) and rel-(2S,5R,6R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-6-hydroxy-2-(2-methylbutanoyloxy)cleroda-3,13(16),14-triene (6). The structures of 1-4 were established on the basis of the interpretation of their 1D and 2D NMR spectral data. The absolute configuration of 4 was determined by the modified Mosher's method. All compounds exhibited promising antimalarial and antimycobacterial activities but also cytotoxicity against three cancer cell lines.
authors.affiliation: Department of Chemistry, Applied Taxonomic Research Center, Faculty of Science, Khon Kaen University, Khon Kaen 40002, Thailand. somdej@kku.ac.th
authors.forename: Somdej
authors.initials: S
authors.lastname: Kanokmedhakul
authors.forename: Kwanjai
authors.initials: K
authors.lastname: Kanokmedhakul
authors.forename: Tanika
authors.initials: T
authors.lastname: Kanarsa
authors.forename: Mongkol
authors.initials: M
authors.lastname: Buayairaksa
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000962:Antimalarials / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D037821:Casearia / Q000737:chemistry*; D045744:Cell Line, Tumor; D045785:Diterpenes, Clerodane / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D015394:Molecular Structure; D024301:Plant Bark / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D013237:Stereoisomerism; D013785:Thailand
chemical_list: D000900:Anti-Bacterial Agents; D000962:Antimalarials; D000972:Antineoplastic Agents, Phytogenic; D045785:Diterpenes, Clerodane