ABSTRACT
Saponin is a kind of complex compounds with triterpenoid or spiral aglycones.Natural saponins are used as substrates,and many novel compounds are obtained by biotransformation technology. Especially, converted products of saponins with strong activities provide valuable lead compounds for the research and development of new drugs. Saponins can be divided into triterpenoid saponin and steroidal saponin according to the structure of the mother nucleus. There are about 89 reported saponin components,including 56 triterpenoid saponins and 33 steroidal saponins. Biological enzyme catalysis,microbial transformation and intestinal microflora transformation are the main bioconversion technologies and key development directions of saponins. The research and optimization technology of biological enzyme and microbial transformation of saponins are the effective methods to prepare active secondary saponins. The biotransformation reaction of saponins mainly includes hydrolysis,redox and rearrangement,resulting in the formation of aglycones,secondary glycosides and their derivatives. The hydrolysis of saponin sugar chains was the main biological transformation pathway, and could generate a number of secondary saponins with less glycosyl groups. The secondary saponins could be absorbed into blood and become real active ingredients in body. Preparation of rare secondary saponins,discovery of lead compounds and development of new drugs are the main directions of biotransformation of saponins. The studies on the metabolism and mechanism of natural saponins by microbial and intestinal microbial biotransformation will also become hotspots. According to relevant papers at home and abroad,the researches on transformation technique,transformation approach and transformation reaction of saponins from natural products in the past thirty years were summarized, and the prospects of research and development were also analyzed to provide scientific basis for further study and comprehensive utilization of these conversion products.
ABSTRACT
Objective: To study the chemical components from the rhizomes of Cyperus rotundus. Methods: The compounds were isolated and purified by chromatographic techniques, and their structures were elucidated by spectral methods. Results: A new isoflavonoid, 5, 7, 4'-trihydroxy-2'-methoxy-3'-prenylisoflavone (1), along with nine phenolic compounds, 6-O-p-hydroxybenzoyl- 6-epi-aucubin (2), 6-O-p-hydroxybenzoyl-6-epi-monomelittoside (3), verproside (4), syringopicroside B (5), syringopicroside C (6), oleuropeinic acid (7), oleuroside (8), 10-hydroxyoleuropein (9), and senburiside I (10), were obtained from the rhizomes of C. rotundus. Conclusion: Compound 1 is a new isoflavone, named cyperotundone A, and compounds 2-10 are isolated from this plant for the first time.
ABSTRACT
Objective: To study the steroidal saponins and phenylic constituents in the bulbs of Lilium lancifolium and their anti-oxidant activities in vitro. Methods: The constituents were isolated and purified by chromatographic technique and recrystallization, and their structures were identified by spectral methods together with physiochemical analyses. The anti-oxidant effects of these constituents on DPPH and ABTS were screened in vitro. Results: Eleven constituents were isolated including seven first-found ones (1-5, 9, and 10) and four known compounds in this plant. They were cis-1-O-p-coumaroylglycerol (1), trans-1-O-p-coumaroylglycerol (2), caffeoyl glyceride (3), 3,4- dihydroxybenzaldehyde (4), salicylic acid (5), (25R,26R)-26-methoxyspirostan-5- ene-3β-O-α-L-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl- (1→6)]-β-D-glucopyranoside (6), (25R,26R)-3β, 17α-dihydroxy-26-methoxyspirostan-5-ene-3β-0-a-Z.-rhamnopyranosyl-(l- >2)-[β-D-glucopyranosyl-(l-"6)]-β-D-glucopyranoside (7), diosgenin 3-O-{O-α-L-rhamnopyranosyl-(1→2)-O-[β-D-xylopyranosyl- (1→3)]-β-D-glucopyranoside} (8), (25R)-3β,17α-dihydroxy- 5α-spirostan-6-one-3-O-α-L-rhamnopyranosyl-(1→2) -β-D-glucopyranoside (9), (25R)-3β-hydroxy-5α-spirostan-6-one-3- O-α-L-rhamnopyranosyl-0 (1→2)-β-D-glucopyranoside (10), and (25R)-spirost-5-ene-3β-O-α-L-rhamnopyranosyl-(1→2) -[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (11). Compounds 1-5 showed the favorable scavenging effects on DPPH and ABTS. Conclusion: The study suggests that the phenylic constituents from the bulbs of L. lancifolium have the anti-oxidant effects.
ABSTRACT
Objective: To study the chemical constituents in the cultured filaments of an antitumor actinomycete strain (N2010-37). Methods: Compounds were isolated and purified by chromatographic techniques and recrystallization, and the structures were identified by spectral methods together with physicochemical analysis. The antitumor effects of these compounds were tested in vitro by MTT method. Results: Three compounds were identified including two anthrones and one novel macrolide. They were (3S, 4R, 7R, 8R, 9S)-3, 8-dihydroxy-4, 7,9-trimethyl-2,6-cyclononanediiolacetone (1), 2-hydroxy-1-methoxy-3- methylanthraquinone (2), and 1, 6, 8-thihydroxy-3-methylanthraquinone (3). Conclusion: Compound 1 is a new compound, and compounds 1 and 3 show the favorable cytotoxic activity against human chronic granulocytic leukemia cell line K562 strain by MTT method in vitro.