Jinlei Liu

A cytotoxic cardenolide and a saponin from the rhizomes of Tupistra chinensis

A new cardenolide tupichinolide (1) and a new steroidal saponin tupichinin A (2), together with seven known compounds, were isolated from the rhizomes of Tupistra chinensis. Their structures were established using spectroscopic analysis and chemical methods. Compound 1 was the first cardenolide isolated from Tupistra chinensis and exhibited potent cytotoxicity against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480.

Studies on chemical fingerprints of Siraitia grosvenorii fruits (Luo Han Guo) by HPLC

A novel, efficient, and accurate fingerprinting method using high performance liquid chromatography–photodiode array detection has been developed and optimized for the investigation and demonstration of the variance in chemical properties among Siraitia grosvenorii fruits from different origins. The effects of growth stages, cultivated varieties, collection locations, and fruit portions of the herb on chromatographic fingerprints were examined. Eleven compounds were identified on chromatograms by comparing the retention time and UV spectrum of each peak separately with those of external references. The results revealed that chromatographic fingerprints, combining similarity or hierarchical clustering analysis along with reference compounds, could efficiently identify and distinguish S. grosvenorii fruits from different sources, which provided helpful clues for studying the plants’ secondary metabolites and benefitted quality control.

A new triterpenoid saponin from the root of Croton lachnocarpus Benth.

A new triterpenoid saponin, 3-O-β-d-xylopyranosyl spathodic acid (1), was isolated from the EtOH extract of the root of Croton lachnocarpus Benth., together with four known compounds. These compounds were characterised on the basis of their spectral data and compatible with values in the literature. Compound 1 was the first triterpenoid glucoside isolated from the genus Croton. The known compound myriaboric acid (2) showed cytotoxic activity against human hepatocellular carcinoma SMMC-7721 cell line with an IC50 value of 42.2 μM.

New Pregnane Glycosides from Brucea javanica and Their Antifeedant Activity

Three new pregnane glycosides, 3‐O‐β‐D‐glucopyranosyl‐(1→2)‐α‐L‐arabinopyranosyl‐(20R)‐pregn‐5‐ene‐3β,20‐diol (1), 3‐O‐α‐L‐arabinopyranosyl‐(20R)‐pregn‐5‐ene‐3β,20‐diol‐20‐O‐β‐D‐glucopyranoside (2), 3‐O‐α‐L‐arabinopyranosyl‐(20R)‐pregn‐5‐ene‐3β,20‐diol‐20‐O‐β‐D‐glucopyranosyl‐(1→2)‐β‐D‐glucopyranoside (3) were isolated along with four known compounds, 4–7, from the leaves and stems of Brucea javanica. Their structures were determined by detailed analyses of 1D‐ and 2D‐NMR spectroscopic data. All of the compounds isolated from Brucea javanica were tested for the antifeedant activities against the larva of Pieris rapae. Compounds 1, 3, and 5 showed significant antifeedant activities after 72 h incubation.

Phenolic Compounds from the Leaves of Castanopsis fargesii.

In the course of a phytochemical and chemotaxonomical investigation of Castanopsis species (Fagaceae), three new phenolic compounds, (3R,1′S)-[1′-(6″-O-galloyl-β-d-gluco-pyranosyl)oxyethyl]-3-hydroxy-dihydrofuran-2(3H)-one (1), (2R,3S)-2-[2′-(galloyl)oxyethyl]-dihydroxybutanoic acid (2), and (3S,4S)-3-hydroxymethyl-3,4-dihydro-5,6,7-trihydroxy-4-(4′-hydroxy-3′-methoxyphenyl)-1H-[2]-benzopyran-1-one (3) were isolated from the fresh leaves of Castanopsis fargesii. In addition, a known phenolic glycoside, gentisic acid 5-O-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (4) was also isolated and identified. Their structures were elucidated by means of spectroscopic methods including one- and two-dimensional NMR techniques.