Hypoglycaemic effect of quinolizidine alkaloids--lupanine and 2-thionosparteine on non-diabetic and streptozotocin-induced diabetic rats.

The hypoglycaemic effects of two quinolizidine alkaloids: lupanine and 2-thionosparteine were examined in non-diabetic and in streptozotocin-induced diabetic rats. The model of experimental diabetes can be considered to be related to diabetes mellitus type 2 with regards to the impairment of beta-cells' secretory function. A single intraperitoneal injection of 2-thionosparteine at a dose of 8.

Quinolizidine alkaloids isolated from Lupinus species enhance insulin secretion.

We have analyzed the effect of quinolizidine alkaloids from Lupinus species upon insulin secretion. Isolated normal rat islets were incubated with 3.3, 8.

The regiochemistry and stereochemistry of the biosynthesis of vitamin B6 from triose units.

13C and 2H NMR spectroscopy has been employed to probe the biosynthesis of vitamin B6 in Escherichia coli. The 13C NMR spectrum of a sample of pyridoxol derived biosynthetically from D-[1,2,3,4,5,6-13C6]glucose shows that the bonds, C(2)-C(3) and C(4)-C(5), of the pyridine nucleus are the only two carbon-carbon bonds of pyridoxol which are generated de novo in the course of its biosynthesis from glucose. It follows that the pyridoxol skeleton is generated from two intact triose units and a triose-derived two-carbon unit, all of which are supplied by glucose.