Isolation and identification of N1-methylnicotinic acid (trigonelline) from rat urine.

Abstract

SummaryA urinary metabolite of nicotinic acid, single and double labeled N1-methylnicotinic acid (trigonelline: Tg) were isolated as urinary excretion products of rats following portal vein injection of [carboxyl 14C] nicotinic acid (14C -NiA) and/or S-adenosyl-L-[methyl-3H]methionine (3H-SAM). The labeled compounds produced were identified as Tg by comparison of ultraviolet absorption pattern and chromatographic be havior with those of the authentic compound, and by cocrystallization with the authentic carrier. It was demonstrated that enzymatic synthesis of double-labeled Tg is accomplished by reaction between 14C-NiA and 3H SAM, and the enzymatic product was identified using the above methods. Approximately 1.5% respectively of the radioactivity of 14C-NiA and 3H SAM was incorporated into Tg by enzymatic reaction. Furthermore, Tg from normal rat urine was isolated by ion-exchange chromatographic procedures and was crystallized from ethyl alcohol. The isolated com pound was identified as Tg by comparison of ultraviolet spectra, infrared spectra, gas-mass spectra, elemental analysis, melting point and thin layer chromatogram behavior with those of the authentic compound. From these results, it was clearly demonstrated that Tg was one of the metabolites of nicotinic acid in the rat.

Anti-Diabetic Effects of Pumpkin and Its Components, Trigonelline and Nicotinic Acid, on Goto-Kakizaki Rats

“…The significant although weak suppression (by dietary TRG and NA, respectively) of the increase in blood glucose level observed after 60 and 120 min in OGTT (Fig. 4C) indicate that TRG, which is a precursor of NA in vivo, 25) may be superior in improving glucose tolerance. On the other hand, the lower insulin level observed in the TRG group than in the NA group at time 0 of OGTT (Fig.…”

“…This result may also indicate that the chemical structure of positively charged TRG with a methyl group lacking in NA was important to the improved glucose tolerance. It also suggests that TRG, which is converted to NA in vivo, 25,[34][35][36][37][38] may be more effective for improving diabetes. Bakhiya et al have reported that a minute structural difference (the presence or absence of an additional methyl group in an alkylated four-ring polycyclic hydrocarbon) could strongly affect the interaction with transporter proteins and direct the excretion route.…”

Neurobehavioral assessment of hydroalcoholic extract ofTrigonella foenum-graecumseeds in rodent models of Parkinson’s disease

“…DOI: 10.3109/13880209.2012.747547 (Saravanan & Pari, 2005;Yen et al, 2005) and functions as a signal transmitter in response to oxidative stress in plants (Berglund, 1994). Further, TGN is a major metabolite of nicotinic acid and is excreted unchanged in urine (Yuyama & Suzuki, 1985) and thus available for protective action on vital organs including neurons. Therefore, neuroprotective potential of SFSE-T shown in the present study can be attributed to TGN, a marker compound of SFSE-T.…”