ABSTRACT
A new dihydroflavone:mirabiflavone (1), together with two known compounds were isolated from the ethyl acetate extract of the roots of Mirabilis himalaica by using various chromatographic techniques, such as silica gel column, Sephadex LH-20 column, and semi-preparative HPLC. Their structures were elucidated as syringaresinol (2) and lariciresinol (3) by spectroscopic analysis. Compounds 2 and 3 were isolated from this plant for the first time.
ABSTRACT
Objective: To study the chemical constituents of the methanol extract from the aerial parts of the mangrove plant Sonneratia paracaseolaris. Methods: The methanol extract was isolated and purified with various chromatographic methods, including silica gel, ODS, Sephadex LH-20 columns, TLC, and HPLC. The compounds were identified by their physical chemical properties and 1H-NMR and 13C-NMR data. Results: Seventeen compounds were obtained from the methanol extract of Sonneratia paracaseolaris and identified as phytol (1), stigmasta-4-ene-3,6-dione (2), stigmata-4,22-diene-3,6-dione (3), cholesterol (4), (22E)-cholesterol-5,22-diene-3β-alcohol (5), diosmetin (6), tricin (7), 5,3′,5′-trihydroxy-7,4′-dimethoxyflavone (8), 5-hydroxy- 7,4′-dimethoxyflavone (9), 5-hydroxyl-7,3′,4′-trimethoxydihydroflavone (10), vanillin (11), p-hydroxy benzaldehyde (12), salicylic acid (13), trans-p-hydroxyl ethyl cinnamate (14), 4-hydroxy-2,6-dimethoxy-benzaldehyde (15), 3,4,5-trimethoxybenzoic acid (16), and 3,3′,4-trimethoxyellagic acid (17). Conclusion: All the compounds except 4, 11, 15, and 17 are obtained from genus Sonneratia. All compounds are isolated from S. paracaseolaris for the first time.
ABSTRACT
OBJECTIVE: To study the chemical constituents of Dendrobium devonianum. METHODS: The compounds were isolated and purified by means of column chromatography with silica gel, Sephadex LH-20 and prep- HPLC. Their structures were identified on the basis of physicochemical parameters and spectroscopic data comparison with standard literature data. RESULTS: Twenty-five compounds were isolated from the 95% ethanol extract of D. devonianum, and identified as 3-hydroxy-4', 5-dimethoxybibenzyl(1), tristin(2), 3, 4', 5-trihydroxybibenzyl(3), N-trans-coumaroyltyramine(4), N-trans- caffeoyltyramine(5), p-hydroxyphenylpropionyltyramine(6), N-cis-coumaroyltyramine(7), 2, 5-dihydroxy-4-methoxy-9, 10-dihydrophenanthrene(8), 2, 4, 7-trihydroxy-9, 10-dihydrophenanthrene(9), 4', 5, 7-trihydroxy-flavonol(10), dihydroconifery acetate(11), ethyl 4-hydroxycinnamate(12), p-hydroxycinnamic acid(13), p-hydroxyphenylpropionic acid(14), 4-hydroxybenzoic acid(15), protocatechuic acid(16), erigeside II(17), citrusin C(18), dihydrosyringin(19), leonuriside A(20), adenosine(21), β-sitosterol(22), daucosterol(23), (+)-syringgaresinol-O-β-D-glucopyranoside(24) and sucrose(25). CONCLUSION: Compounds 1-21 and 24-25 are obtained from this plant for the first time. Compound 1 is isolated from the Dendrobium genus for the first time. Compounds 5, 7, 11, 12 and 18 are obtained from Orchidaceae for the first time.
ABSTRACT
OBJECTIVE: To investigate the chemical constituents of the leaves of Engelhardtia roxburghiana. METHODS: After the plant materials were extracted and fractionated with solvents, column chromatography was used to isolate and purify the compounds. The structures were elucidated on the basis of 1H-NMR, 13C-NMR, MS analysis and comparison with the literature data. RESULTS: Thirteen compounds were identified as following; taxilfolin (1), 5,7,4'-trihydroxy flavanone(2), kaempferol (3), dihydrokaempferol (4), quercetin(5), isoengeletin(6), engeletin (7), astilbin(8), isoastilbin(9), kaempferol-3-O-α-L-rhamnoside(10), eucryphin (11), 5-hydroxy-3,7,3',4'-tetramethoxyflavone(12), quercetin-3-O-α-L-rhamnoside (13). CONCLUSION: Compounds 2, 4, 9, 11 and 12 were identified from the title plant for the first time.
ABSTRACT
OBJECTIVE: To study the chemical constituents of the stem and leaves of Bauhinia glauca (Wall, ex Benth.) Benth. subsp. hupehana (Craib) T. Chen. METHODS: The plant material was extracted with acetone at room temperature. The chemical constituents were isolated by chromatographic methods and their structures were identified by spectroscopic analysis. RESULTS: Five compounds were obtained and identified as (2', 4'-dihydroxy-4-methoxychalcone)-4'-β-Z)-glucoside(1), bauhiniasin (2), sulfuretin(3), isoliquiritigenin(4), and 4'-methylglucoliquiritigenin(5). CONCLUSION: Compound 1 is a new natural product, and this is the first time to find compounds 2 and 4 in this plant and compounds 3 and 5 in this genus.