ABSTRACT
Objective To study the chemical constituents from the leaves of Panax notoginseng and their antioxidant activity (ABTS and DPPH). Methods The constituents were isolated and purified by celite, silica gel, MCI and Sephadex LH-20, reversed-phase MPLC chromatographic methods, then purified by preparative HPLC. Their structures were identified on the basis of mass spectrum and NMR spectrum. Anti-oxidant activity of these compounds was initially investigated. Results Fifteen compounds were isolated from the chloroform, acetone-ethanol (4:1) and acetone-ethanol (1:1) fractions of 95% ethanol extract of the leaves of P. notoginseng, and their structures were elucidated as follows: falcarinol (1), γ-tocopherol (2), (2S,4αS,7αR)-7α-acetyl-3,4,4α,7α- tetrahydro-4α-hydroxy-2,6,7-trimethyl-2-(4,8,12-trimethyltridecyl) cyclopenta [β] pyran-5 (2H)-one (3), picrionoside B (4), linarionoside A (5), viburnolide A (6), quercetin (7), lilyn (8), skimmin (9), apiosylskimmin (10), daphnin methylether (11), 20 (S)-ginsenoside Rh2 (12), ginsenoside F2 (13), 20(R)-ginsenoside Rh2 (14), and isoginsenoside Rh3 (15). Conclusion Compounds 3, 6, and 9-11 are isolated from the plant of genus Panax for the first time, compounds 2 and 4 are isolated from this plant for the first time. Compounds 2, 4, 7, and 8 show certain anti-oxidant activity.
ABSTRACT
Objective: To study the chemical constituents of Yao medicine Zhongliuteng, the canes of Pileostegia tomentella. Methods: The chemical constituents were isolated and purified by silica gel chromatography repeatedly from the canes of P. tomentella and their structures were identified by spectral analysis and chemical methods. Results: Sixteen compounds were isolated from the canes of P. tomentella and their structures were identified as loganic acid (1), 4-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside (4S)-4-hydroxyl-β-ionone (2), resorcinol (3), daphnin (4), skimmin (5), umbelliferone (6), vogeloside (7), diethyl phthalate (8), secologanin (9), secologanin dimethyl acetal (10), sweroside (11), foliasalacioside B (12), benzyl-O-β-D-apiofuranosyl-(1″→6')-β-D-glucopyranoside (13), maltose (14), glucose (15), and daucosterol (16). Conclusion: All compounds are obtained from the plant for the first time, and all compounds are also obtained from the plants of Pileostegia Hook. f. et Thoms. for the first time except compounds 5, 6 and 16.
ABSTRACT
Six coumarins daphnin (1), daphnetin (2), daphnetin glucoside (3), rhodonetin (4), rhodonin (5) and umbelliferone (6) were isolated from the methanolic extract of Rhododendron lepidotum Wall. ex G. Don, Ericaceae (aerial part). The compounds and their acetyl derivatives were screened for antibacterial activity against Staphylococcus aureus ATCC-29213, methicillin resistant Staphylococcus aureus ATCC-15187, Escherichia coli ATCC-8739, Pseudomonas aeruginosa ATCC-9027 by microdilution method as compared to the reference ciprofloxacin. Compound 2 displayed the best antibacterial activity with MIC 125 μg/mL against S. aureus ATCC-29213 and MRSA ATCC-15187 followed by 4 which exhibited the MIC value of 250 μg/mL against all the four tested strains. All molecules showed better antibacterial activity than their acyl derivatives.
Seis cumarinas dafinina (1), dafinetina (2), dafinetina glicosídeo (3), rodonetina (4), rodonina (5) e umbeliferona (6) foram isoladas do extrato metanólico das partes aéreas de Rhododendron lepidotum Wall. ex G. Don, Ericaceae. Os compostos e seus derivados acetilados foram testados para verificar sua atividade antibacteriana contra Staphylococcus aureus ATCC-29213, Escherichia coli resistente à meticilina, Staphylococcus aureus ATCC-15187, ATCC-8739, Pseudomonas aeruginosa ATCC-9027, pelo método de microdiluição, usando ciprofloxacina como referência. A substância 2 apresentou a melhor atividade antibacteriana com o MIC 125 μg/mL contra S. aureus ATCC-29213 e MRSA ATCC-15187 seguido pela substância 4, que apresentou o valor de CIM de 250 μg/mL contra as quatro cepas testadas. Todas as moléculas apresentaram melhor atividade antibacteriana do que seus derivados acetilados.