The UHPLC-QToF-MS analysis of pyrrolizidine alkaloids (PAs) from various parts of 37 botanicals and 7 products was performed. A separation by LC was achieved using a reversed-phase column and a gradient of water/acetonitrile each containing formic acid as the mobile phase. MS-MS detection was used because of its high selectivity, and ability to provide structural information. Free base and N-ox...

The reaction of diphenylcyclopropenone with several N-substituted hydroxylamine and primary amines are investigated. Most of these reactions led to ring opened or ring enlarged products, instead of the desired N-Oxide or imine. The reaction of cyclopropeneimine with peracid-another possible route to N-substituted cyclopropeneimine N-Oxide is studied. Most of the unexpected products are ide...

Abstract Background Many plants contain phytotoxic alkaloids to deter herbivorous pests and grazing animals. Alkaloids include quinolizidine indole found in the lupin ( Lupinus spp.), an ornamental flower emerging protein crop, as well pyrrolizidine ragwort Senecio jacobaea ), invasive, weed-like flower. When lupins ragworts are present large densities fields, there is a concern that may leach ...

n-oxidation of 1,4-dihydro-2,6-dimethyl-1- phenyliminopyridine (7) with several peracids was attempted. the main compound obtained was l-phenyl- 2,6-dimethyl-4-pyridone (8), instead of the expected n-oxide (2). the reaction of phenylhydroxylamine with dimthylrnethoxypyroxonium perchlorate, however, successfully gave the n-oxide (3), which belongs to a class of nitrones in which the diazomethine...

N-Oxidation of 1,4-dihydro-2,6-dimethyl-1- phenyliminopyridine (7) with several peracids was attempted. The main compound obtained was l-phenyl- 2,6-dimethyl-4-pyridone (8), instead of the expected N-oxide (2). The reaction of phenylhydroxylamine with dimthylrnethoxypyroxonium perchlorate, however, successfully gave the N-oxide (3), which belongs to a class of nitrones in which the diazomet...

background: during the initial phase of an infection, there is an upregulation of inducible nitric oxide synthase in the macrophages for the production of nitric oxide. this is followed by the recruitment of polymorphonuclear leukocytes (neutrophils) which release arginase. arginase competes with inducible nitric oxide synthase for a common substrate l-arginine. objective: to investigate whethe...