Guo-Xu Ma

Caesalpins A-H, bioactive cassane-type diterpenes from the seeds of Caesalpinia minax.

Eight new cassane-type diterpenes, caesalpins A-H (1-8), were isolated from the ethyl acetate extract of Caesalpinia minax. Compound 1 displayed significant antiproliferative activity against HepG-2 (IC50 4.7 μM) and MCF-7 (IC50 2.1 μM) cells, and compounds 2 and 4 exhibited selective cytotoxic activities against MCF-7 (IC50 7.9 μM) and AGS (IC50 6.5 μM) cells.

Cassane-type Diterpenes from the Seeds of Caesalpinia minax with Their Antineoplastic Activity

Five new cassane-type diterpenes, neocaesalpin AA (1), neocaesalpin AB (2), neocaesalpin AC (3), neocaesalpin AD (4) and neocaesalpin AE (5), were isolated from Caesalpinia minax together with three known compounds, 12α-methoxyl,5α,14β-dihydroxy-1α,6α,7β-triacetoxycass-13(15)-en-16,12-olide (6), spirocaesalmin (7) and magnicaesalpin (8). Their structures were elucidated based on 1D and 2D NMR, MS and CD analyses. Compounds 1-6 were tested against Hela, HCT-8, HepG-2, MCF-7 and A549 cancer cells and showed moderate cytotoxicity with IC₅₀ values from 18.4 to 83.9 µM.

Antimalarial and Antiproliferative Cassane Diterpenes of Caesalpinia sappan.

Bioassay-guided fractionation of a methanol extract of the seeds of Caesalpinia sappan led to the isolation of 12 new cassane-type diterpenes, caesalsappanins A-L (1-12). Their structures were elucidated on the basis of NMR and HRESIMS analysis, and the absolute configuration of compound 1 was determined by single-crystal X-ray crystallography. All isolated compounds were tested against a chloroquine-resistant Plasmodium falciparum strain for antiplasmodial activities and against a small panel of human cancer cell lines for antiproliferative activities. Compounds 7 and 8 displayed antimalarial activity against the chloroquine-resistant K1 strain of P. falciparum with IC50 values of 0.78 and 0.52 μM and selectivity indices of 17.6 and 16.4, respectively. Compound 10 showed antiproliferative activity against the KB cancer cell line with an IC50 value of 7.4 μM.

Antimalarial diterpene alkaloids from the seeds of Caesalpinia minax

Two new diterpene alkaloids, caesalminines A (1) and B (2), possessing a tetracyclic cassane-type furanoditerpenoid skeleton with γ-lactam ring, were isolated from the seeds of Caesalpinia minax. Their structures were determined by different spectroscopic methods and ECD calculation. The plausible biosynthetic pathway of caesalminines A and B was proposed. The anti-malarial activity of compounds 1 and 2 is presented with IC50 values of 0.42 and 0.79 μM, respectively.

Triterpene saponins from Tabellae Clinopodii.

Three new triterpene saponins, named Clinoposaponin A, Clinoposaponin B, and Clinoposaponin C along with three known triterpene saponins were isolated from the Tabellae Clinopodii. The structures of these compounds were elucidated by means of various spectroscopic analyses. All of the isolated compounds were tested against Hela, HCT-8, AGS, and MCF-7 human cancer cell lines and showed moderate cytotoxic activities with IC₅₀ values between 4.1 and 19.7 μM.

Two new abietane diterpenoid glycosides from Clinopodium chinense

Abstract Two new abietane diterpenoid glycosides, named clinopoditerpenes B (1) and C (2), were isolated from Clinopodium chinese. The structures of the new compounds were determined on the basis of extensive spectral analysis. Compound 1 exhibited cardioprotective effect against H2O2-induced apoptosis in H9c2 cells.

A new cycloartane triterpene glycoside from Souliea vaginata

Abstract A new cycloartane-type triterpene glycoside, namely soulieoside M (1), and one known compound, beesioside I (2), were isolated from the ethanolic extract of the rhizomes of Souliea vaginata. Their structures were determined spectroscopically and compared with previously reported spectral data. Compounds 1 and 2 were evaluated for their cytotoxic activities against three human cancer cell lines.

Norcassane- and cassane-type furanoditerpenoids from the seeds of Caesalpinia sappan

Three novel furanoditerpenoids, norcaesalpinin J (1) featuring an unusual 20-norcassane hydroperoxide and phangininoxys B (2) and C (3) possessing cassane hemiketal skeletons, were isolated from the seeds of Caesalpinia sappan. Their structures were elucidated by extensive spectroscopic methods. All isolates were evaluated for the cytotoxic activities on three human cancer cell lines.

Cassane diterpenes with oxygen bridge from the seeds of Caesalpinia sappan.

The seeds of the medicinal plant Caesalpinia sappan yielded fourteen cassane-type diterpenes, including six new rearranged ones named as caesalppans A-F (1-6). Their structures were elucidated by spectroscopic analysis and comparison with literature data. The isolated new compounds 1-6 possess lactone-type cassane diterpenoid skeleton with an oxygen bridge between C-19 and C-20, and were tested cytotoxic activity against four cancer cell lines using the MTT method.

Four new phenolic acid with unusual bicycle [2.2.2] octane moiety from Clerodendranthus spicatus and their anti-inflammatory activity

Four new phenolic acids, clerodens A-D (1-4) possessing an unusual bicycle [2.2.2] octane moiety were isolated from the whole plants of Clerodendranthus spicatus. Their structures were elucidated by extensive spectroscopic methods, including NMR, MS, and ECD data. All isolates were evaluated for their anti-inflammatory activities on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7, and compound 4 showed significant inhibitory activities with IC50 value of 6.8 μM.