RESUMO
A new steroidal saponin, (23S,24S)-spirosta-5,25(27)-diene-1β,3β,23,24-tetrol 1-O-((2,3-diacetyl-α-Lrhamnopyranosyl)-(1→2)-[β-D-xylopyranosyl-(1→3)]-α-L-arabinopyranoside)-24-O-β-D-glucopyranoside (humilisoside) together with the known β-sitosterol 3-O-glucopyranoside, adenosine, dioscin, and methylprotodioscin were isolated from the leaves of Dracaena humilis. Their structures were elucidated by spectral techniques including mass spectrometry (ESIMS, HRESIMS, tandem MS-MS), 1D NMR (1H, 13 C NMR), 2D NMR (HSQC, 1H-1 H COSY, HMBC, NOESY), chemical method as well as by comparison with spectroscopic data reported in the literature. The chemotaxonomic significance of the isolation of these compounds is discussed. This is the first report on the phytochemical investigation of D. humilis.
RESUMO
A new steroidal saponin, (23S,24S)-spirosta-5,25(27)-diene-1β,3β,23,24-tetrol 1-O-((2,3-diacetyl-α-Lrhamnopyranosyl)-(1→2)-[β-D-xylopyranosyl-(1→3)]-α-L-arabinopyranoside)-24-O-β-D-glucopyranoside (humilisoside) together with the known β-sitosterol 3-O-glucopyranoside, adenosine, dioscin, and methylprotodioscin were isolated from the leaves of Dracaena humilis. Their structures were elucidated by spectral techniques including mass spectrometry (ESIMS, HRESIMS, tandem MS-MS), 1D NMR (1H, 13 C NMR), 2D NMR (HSQC, 1H-1 H COSY, HMBC, NOESY), chemical method as well as by comparison with spectroscopic data reported in the literature. The chemotaxonomic significance of the isolation of these compounds is discussed. This is the first report on the phytochemical investigation of D. humilis.
RESUMO
Chemical investigation of the plant Tristemma hirtum P. Beauv (Melastomataceae) resulted to the isolation of a new flavonol glycoside named quercetin-7-O-α-D-arabinofuranoside (1), together with nine known compounds including 3′-hexadecanoyl-2′-(9aZ)-tetradecanoyl-glycerol 1′-O-[β-D-galactopyranosyl-(1″ → 6″)-α-D-galactopyranoside] (2), arjunolic acid (3), β-sitosterol-3-O-β-D-glucopyranoside (4), terminolic acid (5), quercetin (6), asiatic acid (7), maslinic acid (8), 1β-O-galloylpedunculagin (9) and 6-hydroxyapigenin 7-O-β-D-glucopyranoside (10) from the methanol extract using normal and reversed phase column chromatography. The structures of these compounds were determined by comprehensive interpretation of their spectral data mainly including 1D- 2D-NMR (¹H-¹H COSY, HSQC, and HMBC) spectroscopic and ESI-TOF-MS mass spectrometric analysis.