Yu-Zhi Zhou

Steroidal glycosides from the roots of Cynanchum amplexicaule Sieb. et Zucc.

Seven new steroidal glycosides (amplexicosides A (4), B (7), C (8), D (9), E (10), F (11), and G (12)), along with six known compounds (cynatratoside A (1), tylophoside A (2), cynatratoside B (3), glaucogenin A (5), glaucoside A (6), and hancoside A (13)) were isolated from the 95% ethanol extract of the roots of Cynanchum amplexicaule (Sieb. et Zucc.). Their structures were determined based on spectral and chemical evidence. Compound 12 has a 14, 15-secopregnane-type skeleton aglycone, which has not been reported in literature.

Two new steroidal saponins from Tribulus terrestris

Two new steroidal saponins and two known flavonoid glycosides were isolated from the fruits of Tribulus terrestris. Their structures were assigned by spectroscopic analysis and chemical reaction as 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-12-one-3β,22α,26-triol-3-O-β-d-glucopyranosyl (1 → 2)-β-d-glucopyranosyl(1 → 4)-β-d-galactopyranoside (1), 26-O-β-d-glucopyranosyl-(25S)-5α-furostan-22-methoxy-2α,3β,26-triol-3-O-β-d-glucopyranosyl(1 → 2)-β-d-glucopyranosyl(1 → 4)-β-d-galactopyranoside (2), kaempferol-3-gentiobioside (3), and isorhamnetin-3-gentiobioside (4).

Two New Constituents from Artemisia capillaris Thunb.

Two new compounds, 6′-O-caffeoyl-p-hydroxyacetophenone-4-O-β-D-gluco-pyranoside (1) and 6-amino-9-[1-(3,4-dihydroxyphenyl)ethyl]-9H-purine (2) were isolated from the aerial parts of Artemisia capillaris Thunb. The structures were established on the basis of spectral data.

Two new compounds from Carthamus tinctorius

From the dried petals of Carthamus tinctorius, a new flavonoid, (2R)-4′,5-dihydroxyl-6,7-di-O-β-d-glucopyranosyl flavanone (1) and a new aromatic glucoside, methyl-3-(4-O-β-d-glucopyranosylphenyl) propionate (4) were isolated along with four known compounds (2S)-4′,5-dihydroxyl-6,7-di-O-β-d-glucopyranosyl flavanone (2), 6-hydroxykaempferol-3,6-di-O-β-d-glucopyranoside (3), 4-O-β-d-glucosyl-trans-p-coumaric acid (5), and 4-O-β-d-glucosyl-cis-p-coumaric acid (6). Their structures were identified on the basis of chemical and spectroscopic methods.

Biotransformation of Cinobufagin by Cunninghamella elegans

Cunninghamella elegans has been employed for the biotransformation of cinobufagin to afford 5 metabolites. The structures of the transformation products have been characterized as 12α-hydroxybufagin, 11α-hydroxybufagin, 12β-hydroxy-desacetylcinobufagin, 3-oxo-12α-hydroxybufagin and 12β-hydroxybufagin. Products 12α-hydroxybufagin and 11α-hydroxybufagin are new compounds. In vitro both the biotransformation products and cinobufagin all showed cytotoxic activities against HeLa cells.

New aromatic glucosides from Carthamus tinctorius

Three new aromatic glucosides, 2,3-dimethoxy-5-methylphenyl-1-O-β-d-glucopyranoside (1), 2,6-dimethoxy-4-methylphenyl-1-O-β-d-glucopyranoside (2), and ethyl-3-(4-O-β-d-glucopyranosyl-3-methoxyphenyl)propionate (3), named as carthamosides B1, B2, and B3, respectively, along with three known aromatic glucosides, methyl-3-(4-O-β-d-glucopyranosyl-3-methoxyphenyl)propionate (4), ethylsyringin (5), and methylsyringin (6), have been isolated from the air-dried flower of Carthamus tinctorius. Their structures were identified on the basis of chemical and spectroscopic methods.

Two new compounds from Cynanchum amplexicaule

A new phenolic glycoside, sinapic acid 4-O-β-d-(6′-sinapoyl)glucopyranoside (1) and a new sucrose ester, 6,6′-di-O-sinapoylsurcose (3), were isolated from the roots of Cynanchum amplexicaule (Sieb. et Zucc.), along with two known compounds, 6-O-[E]-sinapoyl-d-glucopyranoside (2) and sibricose A1 (4). Their structures were elucidated on the basis of both chemical and spectroscopic methods.