Structurally modified Cyclovirobuxine-D Buxus alkaloids as effective analgesic agents through Cav3.2 T-Type calcium channel inhibition.

Cyclovirobuxine-D (CVB-D) is a Buxus alkaloid and a major active constituent in the Chinese medicinal herb Buxus microphylls. Traditionally, the natural alkaloid cyclovirobuxine-D has a long history of use as a traditional Chinese medicine for cardiovascular diseases as well as to treat a wide variety of medical conditions. As we found that CVB-D inhibited T-type calcium channels, we designed and synthesized a variety of fragments and analogues and evaluated them for the first time as new Cav3.2 inhibitors. Compounds 2-7 exhibited potency against Cav 3.2 channels, and two of them were more active than their parent molecules. As a result of the in vivo experiments, both compounds 3 and 4 showed significantly reduced writhes in the acetic acid-induced writhing test. Studies of molecular modeling have identified possible mechanism(s) of Cav3.2 binding. Moreover, the relationship between structure and activity was studied in a preliminary manner. Our results indicated that compounds 3 and 4 could play an important role in the discovery and development of novel analgesics.

An efficient and concise synthesis of a selective small molecule non-peptide inhibitor of cathepsin L: KGP94.

KGP94 is a potent, selective, and competitive inhibitor of the lysosomal endopeptidase enzyme (Cathepsin L) currently in preclinical trials for the treatment of metastatic cancer, which is a leading cause of cancer-associated death. Herein, we report two new synthetic routes for synthesizing the target compound through four consecutive steps, using a Weinreb amide approach starting from a common 3-bromobenzoyl chloride. A key step in the approach is a coupling reaction of a readily available Grignard reagent with amide 4 to produce 6, a previously unreported coupling pattern. These new strategies offer an efficient and alternative approach to synthesis of target compound with an excellent overall yield.

Isoorientin, a Selective Inhibitor of Cyclooxygenase-2 (COX-2) from the Tubers of Pueraria tuberosa.

Bioassay-guided fraction of the methanol extract of the roots of Pueraria tuberose DC yielded puerarin, an isoflavone C-glycoside (PT-1), isoorientin, a flavone C-glycoside (PT-2) and mangiferin, a xanthone C-glycoside (PT-3). The extracts and the isolated compounds were screened for potent anti-inflammatory components inhibiting the cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX), the target enzymes of inflammation, by employing spectroscopic/polorographic methods. Among these, isoorientin was found to be a potent inhibitor of COX-2with an IC50 value of 39 µM. Docking studies were carried out to understand the interactions of isorientin (PT-2) with COX-2.The structures of the isolates were determined by mass spectrometry and 2D-NMR techniques including HSQC, HMBC, NOESY and 1H-1H COSY experiments. Although isoorientin and mangiferin have been reported from several plant sources, this is the first report of their isolation from a Pueraria species.

A new di-C-prenylated coumarin from Sophora interrupta.

A new di-C-prenylated coumarin, 7-methoxy-6,8-bis-(2,3-dihydroxy-3-methylbutyl)-coumarin (1), together with seven known compounds, isopimpinellin (2), an arylbenzofuran (3), three flavonoids (4-6), (+)-maackianin (7) and echinoisoflavanone (8), were isolated from the leaves of Sophora interrupta Bedd. The structure of the new compound 1 as well as known compounds was elucidated by extensive 1D and 2D NMR spectral studies.

Two new chalcones from Clerodendrum phlomidis.

Two new chalcones, 3,2',3'-trihydroxy-4'-methoxychalcone (1) and 3,2'-dihydroxy-4',6'-dimethoxychalcone (2), were isolated from the seeds of Clerodendrum phlomidis together with three known flavonoids, 5-hydroxy-7-methoxyflavanone (3), 5-hydroxy-7-methoxyflavone (4), and kaempferol-3-O-α-l-rhamnopyranoside (5). The structures of the new compounds 1 and 2 have been established mainly on the basis of 1D and 2D NMR studies.

Two new chalcones from the flowers of Clerodendrum inerme.

Two new chalcones, 3-hydroxy-3',4'-dimethoxychalcone (1) and 3,2'-dihydroxy-3',4'-dimethoxychalcone (2), were isolated from the flowers of Clerodendrum inerme (L.) Gaertn together with two known flavones, 7-O-methylwogonin (3) and eucalyptin (4). The structures of the new compounds 1 and 2 have been established by extensive 2D-NMR and ESI-TOFMS studies.

A new O-prenylated flavonol from the roots of Sophora interrupta.

A new O-prenylated flavonol, 3',4'-dimethoxy-7-(γ,γ-dimethylallyloxy)flavonol (1), together with three known compounds, 2'-hydroxy-3,4-dimethoxychalcone (2), biochanin A (3) and kaempferol-3-O-ß-D-glucopyranoside (4), were isolated from the roots of Sophora interrupta Bedd. The structure of compound 1 was elucidated by extensive 1D and 2D NMR spectral studies.

Two new flavonoids from the seeds of Derris scandens.

Two new flavonoids, (2S)-3',4',5'-trimethoxyflavanone (1) and 2'-hydroxy-2,4-dimethoxy-4'-O-[(E)-3,7-dimethyl-2,6-octadienyl]chalcone (2), together with a known pterocarpene, flemichapparin B (3), and a known rotenoid, dehydrodeguelin (4), were isolated from the seeds of Derris scandens. Their structures were determined by means of extensive 1D and 2D NMR spectral studies.

A new diacylated labdane diterpenoid from Andrographis wightiana.

A new acylated labdane diterpenoid, 14-deoxy-3,19-diacetyl-11,12-didehydroandrographolide (1), together with three known labdane diterpenoids, wightionolide (2), andrographolide (3) and neoandrographolide (4), and three known flavones, echioidinin (5), skullcapflavone I 2'-methyl ether (6) and echioidin (7), were isolated from the whole plant of Andrographis wightiana. The structure of compound 1 was elucidated by 1D and extensive 2D-NMR spectral studies.