Kiyoshi Murata

Quinoline alkaloids from Orixa japonica

Abstract Six quinoline alkaloids have been newly isolated from a n -hexane extract of Orixa japonica stems. Four alkaloids (pteleprenine, N -demethyllunidonine, N -methylflindersine and 8-methoxy- N -methylflindersine) are described for the first time in this species. Isopteleprenine was obtained as a natural product for the first time; (+)-isoptelefolidine is a new compound. Unambiguous 1 H and 13 C NMR assignments of pteleprenine and isopteleprenine have been achieved.

Potentiation by febrifugine of host defense in mice against Plasmodium berghei NK65

The effect of febrifugine, the main alkaloidal constituent of an antimalarial crude drug, Dichroa febrifuga Lour., on protective immunity in mice infected with erythrocytic stage Plasmodium berghei NK65 was investigated. Febrifugine was administered orally, at a dose of 1 mg/kg/day, to mice before and/or after they were infected intraperitoneally with 2 x 10(6) parasitized red blood cells. Then, mortality and the levels of parasitemia and plasma NO3- [a degradation product of nitric oxide (NO)] were monitored. Febrifugine significantly reduced the mortality and the level of parasitemia. The plasma NO3- concentration began to rise within 2 days after treatment with febrifugine and declined to normal in 2 days when the mice were treated orally with febrifugine once a day for 3 consecutive days before parasite infection. This antimalarial activity of febrifugine was reduced by both N(G)-monomethyl-L-arginine and aminoguanidine. These results indicate that the increased production of NO by febrifugine plays an important role in host defense against malaria infection in mice.

Pharmacological Properties of Pteleprenine, a Quinoline Alkaloid Extracted from Orixa japonica, on Guinea‐pig Ileum and Canine Left Atrium

We have investigated the pharmacological properties of pteleprenine, a quinoline alkaloid, on contractile responses of the guinea‐pig ileum and on inotropic responses of the canine left atrium.

Isolation of (−)-preorixine, a postulated biosynthetic key intermediate of (+)-orixine and related quinoline alkaloids, from the stems of Orixa japonica

A prenyl quinoline alkaloid (-)-preorixine was isolated from the stems of Orixa japonica (Rutaceae) and its structure was elucidated to be (-)-3-(2S,3-epoxy-3-methyl- butyl) - 2,4-dimethoxy-7, 8-methylenedioxyquinoline. (-)-Preorixine is postulated as a biosynthetic key intermediate of (+)-orixine and related compounds

Quantification of Major Royal Jelly Protein 1 in Fresh Royal Jelly by Indirect Enzyme-Linked Immunosorbent Assay

Rabbit polyclonal antibody produced by a major royal jelly protein 1 (MRJP1) specific peptide reacted only with a MRJP1. Indirect ELISA with the antibody revealed a MRJP1 level of 4.12–4.67 g/100 g in different companys royal jelly, which almost agreed with that of a hexametric form of MRJP1 (apisin) measured by high performance liquid chromatography. These results suggest that MRJP1 exists mainly as apisin in royal jelly.

(+)-3′-O-acetylisopteleflorine, a quinoline alkaloid from Orixa japonica

Abstract A new quinoline alkaloid, (+)-3′- O -acetylisopteleflorine, was isolated from a methanol extract of the stems of Orixa japonica . Its structure was elucidated by a combination of NMR analyses and chemical reactions.