ABSTRACT
Objective To investigate the chemical constituents of the whole plants of Viola yedoensis. Methods The chemical constituents were isolated and purified by column chromatography over silica gel and Sephadex LH-20, as well as on the semi-preparative HPLC. The structures of the isolates were identified by the NMR spectroscopic method. Results Twenty-three compounds were isolated and their structures were identified as pubinernoid A (1), (2R,6R,9R)-2,9-dihydroxy-4-megastigmen-3-one (2), 3S,5R-dihydroxy-6R,7-megastigmadien-9-one (3), dehydrovomifoliol (4), blumenol A (5), blumenol B (6), oleanolic acid (7), 2α,3α-dihydroxyurs-12-ene-28-oic acid (8), 1α,2α,3β-trihydroxyolean-12-ene-28-oic acid (9), 2α,19α-dihydroxyursolic acid (10), 3α-hydroxyfriedel-2-one (11), 7-oxopetrosterol (12), 7-oxositosterol (13), syringaresinol (14), lariciresinol (15), daphneticin (16), umbelliferone (17), trans-p-hydroxycinnamic acid methyl ester (18), p-hydroxyphenylpropionic acid (19), p-hydrobenzaldehyde (20), p-methoxybenzaldehyde (21), p-methoxybenzoic acid (22), and 5-hydroxymethyl-2-furfural (23). Conclusion Compounds 1-16 and 18-23 are isolated from the genus Viol for the first time, and compound 17 is isolated from the plant for the first time.
ABSTRACT
Fifteen alkaloids were isolated from the 95% ethanol extract of the whole plants of Viola yedoensis by various column chromatographic techniques such as silica gel and Sephadex LH-20. Their structures were identified as neoechinulin A（1）,N-benzoyl-L-p-hydroxy-phenylalaninol（2）,aurantiamide acetate（3）,aurantiamide（4）,anabellamide（5）,trichosanatine（6）,indole-3-carboxylic acid methyl ester（7）,3-carboxyindole（8）,N-trans-feruloyl-tyramine（9）,paprazine（10）,7'-（3', 4'-dihydroxyphenyl）-N-[(4-methoxyphenyl)ethyl]propenamide（11）,cannabisin F（12）,N-(4-hydroxyphenethyl)octacosanamide（13）,N-(4-hydroxyphenethyl)hexacosanamide（14）and N-benzoyl-L-phenylalaninol（15）. All the compounds except 3 and 4 were isolated from this plant for the first time. These alkaloids exhibited anti-complement activity against the classical pathway(CP)and the alternative pathway(AP)with the CH50 and AP50 values ranging from 0.12 to 0.33 g•L⁻¹ and 0.22 to 0.50 g•L⁻¹, respectively. Preliminary mechanism study using complement-depleted sera showed that these alkaloids acted on different complement components in the complement activation cascade.