Publications by authors named "Yin-yao Niu"

Both enantiomers of 3α-acyloxy-6β-acetoxyltropane derivatives 1-4 were prepared respectively and underwent functional studies and radioreceptor binding assays. 6S Enantiomers showed obvious muscarinic M3, M2 antagonistic activity, while the 6R ones elicited little muscarinic activity by functional studies. Besides, the affinity of 6S enantiomers to muscarinic M3 receptors of rat submandibulary gland, M2 receptors of rat left atria was much larger than that of corresponding 6R enantiomers.

View Article and Find Full Text PDF

A series of lipoamino acids were synthesized and their neuroprotective effect against brain ischemia induced by oxygen-glucose deprivation (OGD) on rat cerebral slices was evaluated. Among these compounds, N-stearoyl-L-tyrosine (4), N-stearoyl-L-serine (5) and N-stearoyl-L-threonine (6) exhibited good neuroprotective activity. We found that the neuroprotective activity of lipoamino acids depended on the acyl group, the presence of a free carboxylic function and a free hydroxyl group at the branched chain of the amino acids.

View Article and Find Full Text PDF

Both enantiomers of 2, 3, and 4, three bioactive analogs of muscarinic agonist BGT-A were prepared respectively and underwent functional studies and radioreceptor binding assays. 6S enantiomers of 2, 3, and 4 showed obvious muscarinic activity, while 6R ones elicited little muscarinic activity by functional studies. Besides, the affinity of 6S enantiomers of 2, 3, and 4 was greatly larger than that of their 6R enantiomers respectively.

View Article and Find Full Text PDF

Two naturally occurring tropane alkaloids, anisodamine and scopolamine, structurally dissimilar in one OH group, are well established as muscarinic acetylcholine receptor (mAChR) antagonists in clinic and basic research. However, experimental evidence for central effects of anisodamine is limited and conflicting compared with that of scopolamine. In the present study, Morris water maze test, long-term potentiation (LTP) recording and receptor radioligand binding assays were used to explore the disparity in neuropsychopharmacological influences of anisodamine versus scopolamine and possible mechanisms.

View Article and Find Full Text PDF

Aim: To study the stereoselectivity of satropane (3-paramethylbenzene sulfonyloxy-6-acetoxy tropane), a novel tropane analog, on iris muscarinic receptor activation and intraocular hypotension.

Methods: The assays for radioligand-receptor binding, the contractile responses of isolated iris muscle, the miosis response, and the intraocular hypotension of the enantiomers of satropane were investigated.

Results: In the binding analysis, S(-)satropane (lesatropane) completely competed against the [3H]quinuclydinyl benzilate-labeled ligand at muscarinic receptors in the iris muscle, whereas R(+)satropane failed to completely compete.

View Article and Find Full Text PDF

IN THE TITLE COMPOUND [SYSTEMATIC NAME: (1R,3S,5R,6S)-8-methyl-3-(4-methyl-phenyl-sulfon-yloxy)-8-aza-bicyclo-[3.2.1]octan-6-yl acetate], C(17)H(23)NO(5)S, the fused piperidine ring exists in a chair conformation with the N atom and one C atom displaced by 0.

View Article and Find Full Text PDF

Muscarinic M2 receptor antagonists with high subtype selectivity (M2/M1) will decrease the toxicity in central nervous system in treatment of AD. The exploration of quantitative structure-selectivity relationship (QSSR) to muscarinic M2 receptor antagonists will provide design information for drug with fewer side effects. In this paper, CoMFA models of pK(i)(M1), pK(i)(M2) and p[K(i)(M2)/K(i)(M1)] (pK(i)(M2)-pK(i)(M1)) were used to study the subtype selectivity (M2/M1) of piperidinyl piperidine derivatives as muscarinic M2 subtype receptor antagonists.

View Article and Find Full Text PDF

Baogongteng A (BGT-A), a naturally occurring tropane muscarinic agonist isolated from Chinese medicinal plant, exhibits a bioactive effect different from those of many tropane alkaloids that are muscarinic antagonists. A series of racemic derivatives of BGT-A was synthesized to study the structure-activity relationships (SAR). To explore further the SAR in this series and to ultimately design muscarinic agonists for drug development, a Comparative Molecular Field Analysis (CoMFA) was performed.

View Article and Find Full Text PDF