Search results for "Levorotatory"
showing 3 items of 3 documents
A Selective Synthesis of Fluorinated Cispentacin Derivatives
2014
A facile selective method has been developed for the synthesis of new fluorine-containing cispentacin stereoisomers. Mono- and difluorinated cispentacin derivatives were synthetized from a bicyclic β-lactam in five or six steps involving a regio- and stereoselective hydroxylation through iodooxazoline formation, followed by deoxygenation by fluorination. Starting from an enantiomerically pure bicyclic β-lactam obtained by enzymatic resolution of the racemic compound, an enantiodivergent procedure allowed the preparation of both dextro- and levorotatory difluorinated cispentacins.
Left, Right, or Both? On the Configuration of the Phenanthroindolizidine Alkaloid Tylophorine from Tylophora indica
2013
The alkaloid (-)-tylophorine was isolated from a sample of Tylophora indica, and the crude extract was analyzed by HPLC/MS(n) and chiral HPLC/MS. While the literature states that the naturally occurring form of this alkaloid is the R-enantiomer and that its S-antipode is usually not found in nature, we confirmed the hypothesis of Govindachari and Nagarajan that natural levorotatory tylophorine is indeed a nearly racemic mixture with a slight excess of the R-enantiomer.
A comparison of the antihypertensive action of propranolol and the optical isomers of N-isopropyl-p-nitrophenylethanolamine (INPEA)
1969
In hypertensive patients, the effect of propranolol and of the optical isomers of N-isopropyl-p-nitrophenylethanolamine (INPEA) on blood pressure was studied. Single oral doses of 40 mg propranolol, 700 mg (−)-INPEA and 700 mg (+)-INPEA decreased supine systolic as well as standing systolic and diastolic blood pressure. Single intravenous doses of 75 mg (−)-INPEA and 75 mg (+)-INPEA lowered supine systolic and diastolic blood pressure. The antihypertensive action of the beta adrenergic blocking levorotatory isomer of INPEA and of the dextrorotatory isomer, which is devoid of beta adrenergic blocking activity, did not differ. It is concluded from these results that the antihypertensive actio…