Pharmacokinetics and pharmacodynamics of temocapril during repeated dosing in elderly hypertensive patients

Synthesis of Novel 2,3-Dihydro-1,5-Benzothiazepines as α-Glucosidase Inhibitors: In Vitro, In Vivo, Kinetic, SAR, Molecular Docking, and QSAR Studies

In the present study, a series of 2,3-dihydro-1,5-benzothiazepine derivatives 1B-14B has been synthesized sand characterized by various spectroscopic techniques. The enzyme inhibitory activities of the target analogues were assessed using in vitro and in vivo mechanism-based assays. The tested compounds 1B-14B exhibited in vitro inhibitory potential against α-glucosidase with IC₅₀ = 2.62 ± 0.16 to 10.11 ± 0.32 μM as compared to the standard drug acarbose (IC₅₀ = 37.38 ± 1.37 μM). Kinetic studies of the most active derivatives 2B and 3B illustrated competitive inhibitions. Based on the α-glucosidase inhibitory effect, the compounds 2B, 3B, 6B, 7B, 12B, 13B, and 14B were chosen in vivo for further evaluation of antidiabetic activity in streptozotocin-induced diabetic Wistar rats. All these evaluated compounds demonstrated significant antidiabetic activity and were found to be nontoxic in nature. Moreover, the molecular docking study was performed to elucidate the binding interactions of most active analogues with the various sites of the α-glucosidase enzyme (PDB ID 3AJ7). Additionally, quantitative structure-activity relationship (QSAR) studies were performed based on the α-glucosidase inhibitory assay. The value of correlation coefficient (r) 0.9553 shows that there was a good correlation between the 1B-14B structures and selected properties. There is a correlation between the experimental and theoretical results. Thus, these novel compounds could serve as potential candidates to become leads for the development of new drugs provoking an anti-hyperglycemic effect.

Organocatalytic asymmetric addition of thioglycolates to o-quinone methides: a route to 5-substituted-5H-benzoxathiepine-2(3H)-ones

Herein we have developed the first enantioselective synthesis of 5-substituted-5H-benzoxathiepine-2(3H)-ones. 2-Sulfonylmethyl phenols and thioglycolates were employed as reaction partners in this method. The desired thia Michael products were obtained via bifunctional squaramide catalyzed conjugate addition reaction to in situ generated o-quinone methides and then basic hydrolysis followed by cyclization led to the formation of 5-substituted-5H-benzoxathiepine-2(3H)-ones. Broad scope and moderate to high enantioselectivities were observed for both products.

Endothelium-derived hydrogen peroxide accounts for the enhancing effect of an angiotensin-converting enzyme inhibitor on endothelium-derived hyperpolarizing factor-mediated responses in mice

Background- We have recently identified that endothelium-derived hydrogen peroxide (H2O2) is an endothelium-derived hyperpolarizing factor (EDHF) in animals and humans, for which endothelial nitric oxide synthase (eNOS) is an important source. Angiotensin-converting enzyme (ACE) inhibitors are known to enhance EDHF-mediated responses. In this study, we examined whether endothelium-derived H2O2 accounts for the enhancing effect of an ACE inhibitor on EDHF-mediated responses and, if so, what mechanism is involved.

METHODS AND RESULTS

Control and eNOS-/- mice were maintained with or without temocapril (10 mg/kg per day orally) for 4 weeks, and isometric tensions and membrane potentials of mesenteric arteries were recorded. In control mice, temocapril treatment significantly enhanced EDHF-mediated relaxations and hyperpolarizations to acetylcholine (n=8 each). Catalase, a specific scavenger of H2O2, abolished the beneficial effects of temocapril, although it did not affect endothelium-independent relaxations to sodium nitroprusside or NS1619, a direct opener of K(Ca) channels (n=6 each). Western blot analysis demonstrated that the temocapril treatment significantly upregulated the expression of eNOS. By contrast, this enhancing effect of temocapril was absent in eNOS-/- mice (n=6).

CONCLUSIONS

These results indicate that endothelium-derived H2O2 accounts for the enhancing effect of temocapril on EDHF-mediated responses caused in part by eNOS upregulation, further supporting our H2O2 theory.

Converting enzyme inhibitor temocaprilat prevents high glucose-mediated suppression of human aortic endothelial cell proliferation

We examined the involvement of the oxidative stress in high glucose-induced suppression of human aortic endothelial cell proliferation. Chronic glucose treatment for 72 h concentration-dependently (5.6-22.2 mol/l) inhibited human coronary endothelial cell proliferation. Temocaprilat, an angiotensin-converting enzyme inhibitor, at 10 nmol/l to 1 micromol/l inhibited high glucose (22.2 mmol/l)-mediated suppression of human aortic endothelial cell proliferation. Temocaprilat at 1 micromol/l inhibited high glucose-induced membrane-bound protein kinase C activity in human aortic endothelial cells. The protein kinase C inhibitors calphostin C 100 nmol/l or chelerythrine 1 micromol/l inhibited high glucose-mediated suppression of human aortic endothelial cell proliferation. Chronic high glucose treatment for 72 h increased intracellular oxidative stress, directly measured by flow cytometry using carboxydichlorofluorescein diacetate bis-acetoxymethyl ester, and this increase was significantly suppressed by temocaprilat 10 nmol/l to 1 micromol/l. Bradykinin B2 receptor antagonist icatibant 100 nmol/l significantly reduced the action of temocaprilat; whereas bradykinin B1 receptor antagonist des-Arg9-Leu8-bradykinin 100 nmol/l had no effect. These findings suggest that high glucose inhibits human aortic endothelial cell proliferation and that the angiotensin-converting enzyme inhibitor temocaprilat inhibits high glucose-mediated suppression of human aortic endothelial cell proliferation, possibly through suppression of protein kinase C, bradykinin B2 receptors and oxidative stress.

1,4-thiazepines, 1,4-benzothiazepin-5-ones, and 1,4-benzothioxepin orthoamides via multicomponent reactions of isocyanides

The intramolecular Ugi four-component condensation between 6-oxo-4-thiacarboxylic acids, benzylamines, and cyclohexyl isocyanide gave hexahydro-1,4-thiazepin-5-ones and 1,4-benzothiazepin-5-ones, in some cases with high stereoselectivity, and the intramolecular Passerini three-component reaction, in the presence of catalytic amine, gave tetracyclic 1,4-benzothioxepin orthoamides.