Synthesis and antitumor activity of α,ß-unsaturated carbonyl moiety- containing oleanolic acid derivatives targeting PI3K/AKT/mTOR signaling pathway.

Oleanolic acid (OA) and its semi-synthetic derivatives have been reported to have a wide range of biological activities. The introduction of electrophilic Michael acceptor group can increase the reactivity of OA to cellular targets and thus improve the anti-tumor activity. In this work, a series of novel α,ß-unsaturated carbonyl derivatives of OA were designed and synthesized. Their in vitro cytotoxic activity against MCF-7, HepG2 and HeLa cells were tested. Most derivatives exhibited improved cell growth inhibitory activity, especially for 3d with an IC50 of 0.77 µM in MCF-7 cells. Moreover, 3d inhibited the migration of MCF-7 and HeLa cells at the concentration of 4 µM. Flow cytometric analysis revealed that 3d induced cell apoptosis and S phase arrest in a concentration-dependent manner. Western blotting experiment demonstrated that 3d inhibited the phosphorylation of AKT and mTOR. These results suggest that this series of OA derivatives bearing exocyclic methylene ketone pharmacophore are promising anticancer agents as potential PI3K/AKT/mTOR pathway inhibitors.

Synthesis and evaluation of effective photoaffinity probe molecule of furospinosulin-1, a hypoxia-selective growth inhibitor.

The synthesis and evaluation of a photoaffinity probe molecule for furospinosulin-1, a hypoxia-selective growth inhibitor that we identified from marine sponge, was studied. An analogue carrying an alkyne tail showed potent hypoxia-selective inhibitory activity exceeding that of the parent molecule, and exhibited in vivo anti-tumor activity following oral administration. The alkyne moiety in the analogue was also found to be a good anchoring group for the preparation of probe molecules; a photoaffinity probe molecule having an optimized spacer length was selected through the systematic synthesis of several probes and the evaluation of their hypoxia-selective growth inhibitory activity and electrophoretic mobility shift properties.

Probe molecule equipped with boronic acid moiety as a reversible cross-linking group improves its binding affinity.

Syntheses of biotinylated probe molecules of L-glutathione (GSH) equipped with boronic acid moiety and evaluation of their binding affinities against glutathione-S-transferase (GST) were described. It revealed that the presence of boronic acid moiety in an appropriate position enhances binding affinity of GSH probe toward GST probably by forming a reversible cross-link. Among prepared, the boronate-containing probe 8b exhibited the highest recovering ability of GST from Escherichia coli cell lysate.

A new eudesmane sesquiterpene lactone from Curcuma wenyujin.

The aim of the study was to investigate the sesquiterpene constituents from the rhizomes of Curcuma wenyujin Y. H. Chen et C. Ling. The isolation and purification of the constituents from the 50% EtOH extracts of the rhizomes were performed with repeated column chromatography over sillica gel and macroporous resin. Eight sesquiterpenes were obtained and identified as wenyujinlactone A (1), neolitamone A (2), zedoarondiol (3), isozedoarondiol (4), aerugidiol (5), curcumol (6), curdione (7) and (1R, 10R)-epoxy-(-)-1, 10-dihydrocurdine (8) by means of spectral analysis. Among them, compound 1 was found to be a new eudesmane sesquiterpene lactone, whilst compounds 2-5 were obtained from this plant for the first time.