Chemical constituents and biological activities of bauhinia sirindhorniae and croton hutchinsonianus

Abstract

Phytochemical study of the stems and roots of Bauhinia sirindhorniae K. & SS. Larsen led to the isolation of seventeen known compounds, two cyanoglucosides (lithospermoside and menisdaurin), one flavan ((-)-epicatechin), two flavanones ((2S)-naringenin and (2S)-eriodictyol), one flavanonol ((+)-taxifolin), one flavone (luteolin), one chalcone (isoliquiritigenin), one chromone (5,7-dihydroxychromone), one chromone glucoside (5-hydroxychromone 7-beta-D-glucoside), two lignan glycosides ((+)-isolariciresinol 3alpha-O-alpha-L-rhamnoside and (+)-lyoniresinol 3alpha-O-alpha-L-rhamnoside), two triterpenoids (lupeol and glutinol), one steroid glucoside (sitosteryl-3-O-beta-D-glucoside) and other phenolic compounds (3,4,5-trimethoxyphenolic-1-O-beta-D-glucoside and protocatechuic acid). Additionally, six compounds were obtained from the phytochemical investigation of the branches and leaves of Croton hutchinsonianus Hosseus. These included two new compounds 3-(4-hydroxy-3,5-dimethoxyphenyl)-propyl benzoate and 3-(4-hydroxyphenyl)-propyl benzoate and other four known compounds, namely farnesyl acetone, poilaneic acid, 4-hydroxybenzaldehyde and dihydroconiferylbenzoate. The structure determination of all isolates were accomplished by spectroscopic methods and compared with the previously reported data of known compounds. The isolated compounds were also subjected to biological evaluations, for antibacterial, antifungal, cytotoxic and free radical scavenging activities. (+)-Isolariciresinol 3alpha-O-alpha-L-rhamnoside and (+)-lyoniresinol 3alpha-O-alpha-L-rhamnoside showed free radical scavenging activity. (2S)-eriodictyol and isoliquiritigenin showed activity against Bacillus subtilis and Staphylococcus aureus whereas (2S)-naringenin and luteolin exhibited activity against Bacillus subtilis. Furthermore, 3-(4-hydroxy-3,5-dimethoxyphenyl)-propyl benzoate, dihydroconiferyl benzoate and 3-(4-hydroxyphenyl)-propyl benzoate revealed moderate antifungal activity againstCandida albicans. In addition, 3-(4-hydroxy-3,5-dimethoxyphenyl)-propyl benzoate showed weak cytotoxic activity against NCI-H187 cell line while dihydroconiferylbenzoate and 3-(4-hydroxyphenyl)-propyl benzoate were inactive