ABSTRACT
This chapter covers the chemistry, biochemistry, and biological effects of aliphatic nitrocompounds from higher plants, particularly those of the genus Astragalus (Leguminosae). Primary nitrocompounds have the general formula RCH2NO2 in which the nitro (NO2) group is linked through nitrogen to the a-carbon. Nitroalkanes are practically insoluble in water, but they dissolve in aqueous alkali because the hydrogen on the a-carbon is acidic, reacting with base to form the nitronate anion. Biosynthetic studies were originally conducted with the ascomycete fungus Penicillium atrovenetum which synthesizes NPA. Tracer studies were conducted at various laboratories, and these have been reviewed by Venulet and Van Etten1 and by Wilson. Higher levels of plasma nitrite are usually observed when NPOH is given intraruminally than when NPA is given,61 and this is reflected in the higher level of methemoglobin after administration of NPOH.
