12-Oleanene-3,6-diol

(1S,2E,4S,7E,11E)-2,7,11-Cembratriene-4,6-diol semisynthetic analogs as novel c-Met inhibitors for the control of c-Met-dependent breast malignancies.[Pubmed:27681240]

Bioorg Med Chem. 2016 Nov 15;24(22):5748-5761.

(1S,2E,4S,6R,7E,11E)-2,7,11-Cembratriene-4,6-diol (1) and its 4-epi-analog (2) are the cembranoid precursors to several key flavor ingredients in most Nicotiana (tobacco) species. Nearly 40-60% of 1 and 2 are purposely degraded during the commercial tobacco fermentation. However, 1 and 2 display promising bioactivities, including anticancer. Breast cancer is the most diagnosed cancer in women and ranked second female disease killer. The receptor tyrosine kinase c-Met correlates with aggressiveness of certain breast cancer phenotypes and thus considered a valid therapeutic target. This study reports the discovery and optimization of the tobacco-based cembranoid 1 as a novel c-Met inhibitory scaffold using combined structure- and ligand-based approaches. 1 displayed antiproliferative, anti-migratory and anti-invasive effects against the c-Met overexpressing MDA-MB-231 breast cancer cells at moderate muM concentrations. The Z'-LYTE kinase platform and Western blot analysis identified c-Met as a potential macromolecular target. Rationally designed carbamate analogs were proposed to probe additional targeted c-Met interactions and improve the cellular potency. The 6-phenyl carbamate 3 showed enhanced c-Met inhibitory activity. Structure-activity relationships of different substituents on the 3's phenyl moiety were studied. The most active analog 20 showed potent in vitro anticancer activity against the MDA-MB-231 breast cancer cells at low muM concentrations, with minimal toxicity on the non-tumorigenic MCF-10A mammary epithelial cells. Cembranoid 20 potently inhibited the c-Met catalytic activity in Z'-LYTE kinase assay and various cellular c-Met-driven signaling pathways. Furthermore, 20 displayed a robust antitumor activity in a breast cancer xenograft athymic mouse model and thus promoted to the lead rank. Cembranoids are novel c-Met inhibitors appropriate for future use to control c-Met dependent malignancies.

Neuroprotective activity of (1S,2E,4R,6R,-7E,11E)-2,7,11-cembratriene-4,6-diol (4R) in vitro and in vivo in rodent models of brain ischemia.[Pubmed:25677097]

Neuroscience. 2015 Apr 16;291:250-259.

(1S,2E,4R,6R,-7E,11E)-2,7,11-cembratriene-4,6-diol (4R) is a precursor to key flavor ingredients in leaves of Nicotiana species. The present study shows 4R decreased brain damage in rodent ischemic stroke models. The 4R-pretreated mice had lower infarct volumes (26.2+/-9.7 mm3) than those in control groups (untreated: 63.4+/-4.2 mm3, DMSO: 60.2+/-14.2 mm3). The 4R-posttreated rats also had less infarct volumes (120+/-65 mm3) than those in the rats of the DMSO group (291+/-95 mm3). The results from in vitro experiments indicate that 4R decreased neuro2a cell (neuroblastoma cells) apoptosis induced by oxygen-glucose deprivation (OGD), and improved the population spikes' (PSs) recovery in rat acute hippocampal slices under OGD; a phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin, abolished the effect of 4R on PSs recovery. Furthermore, 4R also inhibited monocyte adhesion to murine brain-derived endothelial (bEND5) cells and upregulation of intercellular adhesion molecule-1(ICAM-1) induced by OGD/reoxygenation (OGD/R), and restored the p-Akt level to pre-OGD/R values in bEND5 cells. In conclusion, the present study indicates that 4R has a protective effect in rodent ischemic stroke models. Inhibition of ICAM-1 expression and restoration of Akt phosphorylation are the possible mechanisms involved in cellular protection by 4R.

The tobacco cembranoid (1S,2E,4S,7E,11E)-2,7,11-cembratriene-4,6-diol as a novel angiogenesis inhibitory lead for the control of breast malignancies.[Pubmed:28583806]

Bioorg Med Chem. 2017 Aug 1;25(15):3911-3921.

(1S,2E,4S,6R,7E,11E)-2,7,11-cembratriene-4,6-diol (1) and its 4-epi-analog (2) are diterpene precursors of the key flavor components in most Nicotiana (tobacco) species that purposely degraded during commercial tobacco fermentation. Angiogenesis, recruitment of new blood vessels, is important for tumor growth, survival and metastasis that can be targeted to control cancer. This study shows evidences and potential of the cembranoid 1 as a potent angiogenesis modulator through targeting VEGFR2. In silico study suggested favorable docking scores and binding affinity of 1 at the ATP binding pocket of VEGFR2. The binding mode of 1 was parallel to the standard FDA-approved antiangiogenic drug sunitinib (4). In vitro, cembranoid 1 significantly reduced the activated VEGFR2 levels in multiple breast cancer cell lines. Intraperitoneal 40mg/kg, 3X/week treatment of 1 significantly reduced the MDA-MB-231 cells breast tumor size in mice. Immunohistochemistry and Western blotting analysis of the treated mice tumors showed significant downregulation of the vasculogenesis marker CD31 and suppressed activated VEGFR2-paxillin-FAK pathway. Matrigel study in Swiss albino mice showed similar trend. The tobacco cembranoid 1 is a potential antiangiogenic lead useful for future use to control breast malignancies.

Design and Synthesis of 2-Alkylpyrimidine-4,6-diol and 6-Alkylpyridine-2,4-diol as Potent GPR84 Agonists.[Pubmed:27326330]

ACS Med Chem Lett. 2016 Mar 30;7(6):579-83.

A series of alkylpyrimidine-4,6-diol derivatives were designed and synthesized as novel GRP84 agonists based on a high-throughput screening (HTS) hit 1. 6-Nonylpyridine-2,4-diol was identified as the most potent agonist of GPR84 reported so far, with an EC50 of 0.189 nM. These novel GPR84 agonists will provide valuable tools for the study of the physiological functions of GPR84.