Search

Sixteen lignanoids were isolated from an aqueous extract of the commonly used Chinese traditional medicine Dangshen, the dried roots of Codonopsis pilosula, by using a combination of various chromatographic techniques, including silica gel, macroporous adsorbent resin, MCI resin, sephadex LH-20, and reversed phase semi-preparative HPLC. On the basis of spectral data analysis, their structures were elucidated and identified as（-）-（7R,7’R,8R,8’S）-4,4’-dihydroxy-3,3’,5,5’,7-pentamethoxy-2,7’-cyclolignane（1）,（-）-（7R,8S）- dihydrodehydrodiconiferyl alcohol 4-O-β-D-glucopyranosyl-（1’’’→2’’）-β-D-glucopyranoside（2）,（-）-（7R,8S）- dihydrodehydrodiconiferyl alcohol（3）,（+）-（7S,8R）-dehydrodiconiferyl alcohol（4）,（+）-balanophonin（5）,（+）- demethoxypinoresinol（6）,（+）-pinoresinol（7）,（+）-epipinoresinol（8）,（-）-syringaresinol（9）,（-）-medioresinol（10）,（-）-lariciresinol（11）,（-）-secoisolariciresinol（12）,（-）-ent-isolariciresinol（13）,（+）-（7S,8S）-3-methoxy-3’,7- expoxy-8,4’-neolignan-4,9,9’-triol（14）,（+）-（7S,8R）-3’,4-dihydroxy-3-methoxy-8,4’-neolignan（15）, and（-）-（7R,8R）-3’,4-dihydroxy-3-methoxy-8,4’-neolignan（16）. All these compounds were isolated from C. pilosula for the first time, while compound 1 is a new natural product of 2,7’-cyclolignan and 2 is a new 4’,7-epoxy- 8,3’-neolignan diglucoside. Compound 12 showed activity against Fe(2+)-cysteine induced rat liver microsomal lipid peroxidation with an inhibition ratio of（63.4 ± 8.3） % at 1×10(-5) mol·L(-1).

By using a combination of various chromatographic techniques including column chromatography over silica gel and Pharmadex LH-20 and reversed-phase HPLC, two minor new compounds, labda-12, 14-dien-6beta, 7alpha, 8beta, 17-tetraol (1), 2, 3-cis-6-acetyl-5-hydroxy-2-(hydroxymethylvinyl)-2, 3-dihydrobenzofuran-3-ol angelate (2), and a minor new natural product 6-methoxy-4-methyl-3, 4-dihydro-2H-naphthalen-1-one (3) have been isolated from an ethanolic extract of Heteroplexis micocephala. Their structures were elucidated with spectroscopic data analysis including 2D NMR experiments.

To improve the profile of 20 (S)-camptothecin, a series of 20-O-linked camptothecin phenoxyacetic acid ester derivatives have been designed.These derivatives were synthesized by the method of acylation. Their chemical structures were confirmed with 1HNMR, IR, MS, and HRMS. The cytotoxicities of the compounds were tested by MTT assay. The in vivo antitumor activities of these esters were evaluated against mouse liver tumor H22 in mice.Twelve derivatives of camptothecin ester are new compounds.In vitro and in vivo antitumor activity has indicated that some derivatives appeared significantly more effective than topotecan in the H22 mouse liver tumoral model.