Isolation, X-ray crystal structure and theoretical calculations of the new compound 8-Eepicordatin and identification of others terpenes and steroids from the bark and leaves of Croton palanostigma Klotzsch

• Autor(a) principal: Brasil,Davi S. B.
• Data de Publicação: 2010
• Outros Autores: Müller,Adolfo H., Guilhon,Gisele M. S. P., Alves,Cláudio N., Peris,Gabriel, Llusar,Rosa, Moliner,Vicent
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532010000400021
• topic: Croton palanostigma Klotzsch; terpenes; steroids; NMR DFT calculations; X-ray crystallography

Phytochemical studies of the bark and leaves of Croton palanostigma Klotzsch (Euphorbiaceae) led to the isolation of a new clerodane diterpene, 8-epicordatin (2), in addition to 12-oxohardwickiic acid methyl ester (3), aparisthman, cordatin (1), ent-trachyloban-18-oic acid, ent-13-epimanoyl oxide, ent-3-oxo-13-epimanoyl oxide, ent-3β-hydroxy-13-epimanoyl oxide, sitosterol, stigmasterol, stigmastan-3-one, 6β-hydroxystigmast-4-en-3-one, 6β-hydroxystigmasta-4,22-dien-3-one, stigmast-4-en-3-one, stigmasta-4,22-dien-3-one, 3-O-acetylaleuritolic acid, 11α-hydroxyurs-12-en-3-one, α-amyrenone, 24-methylenecycloartenone and lupenone. These compounds were isolated using typical phytochemical procedures and the structures were deduced from spectroscopic studies, including 2D NMR experiments. In addition, the crystalline structure of 8-epicordatin (2) was determined by X-ray diffraction. NMR theoretical calculations at the B3PW91/DGDZVP level were used to confirm the assignment of the chemical shifts of the H-7α and H-7β hydrogens of 8-epicordatin.