Thionicotinamide

N4. Nordin, J. H., and Bretthauer, R. K., Colorimetric detection of carriers of galactosemia based on thionicotinamide diphosphopyridine nucleotide (TNDPN) reduction. Federation Proc. 20, 256 (1961). 

Thionicotinamide adenine dinucleotide glyceraldehyde-3-phosphate dehydrogenase and, 30... 

Fig. 19.4. Thionicotinamide capped gold nanoparticles (A) before, (B) after 1 min and (C) after 30 min of 532 nm laser excitation. (From [78].)...

PARP inhibitors have been synthesized (11) and are shown in Figs. 11.4 and 11.5. Some of them have been tested in stroke models with good results in terms of preventing infarction (12-18). Most of the inhibitors are based on the structure of nicotinamide and therefore bind to the nicotinamide site of PARP. Several inhibitors are well known, such as nicotinamide, benzamide, and 3-aminobenzamide (19,20). However, new quinazolinone, phen-anthradinone, and other inhibitors are being investigated. Nicotinamide has a of about 5 xM for PARP (19). Activity is decreased in 6-aminonicotinamide, isonicotinamide, 1-methylnicotinamide, 5-methylnicotinamide, 8-methylnicotinamide, and thionicotinamide (Table 11.1 >... 

D-Glucitol dehydrogenase has broad substrate-specificity. The enzyme oxidizes D-glucitol, L-iditol, ribitol, and xylitol in the presence of NAD+ cofactor.414 424 NAD+ can be replaced by 3-acetylpyridine adenine dinucleotide (AcPyAD), 3-thionicotinamide adenine dinucleotide (TNAD), or nicotinamide hypoxanthine dinucleotide (NHD).414... 

The preparation of the 3-diethyl ami no-1 -ethylisothiazolo[3,4-6]pyridinium perchlorate 197 smoothly proceeded on treatment of the 2-ethylamino-Ar,Af-diethyl-thionico-tinamide 196 with sulfuryl chloride in chloroform in 90% yield (82S972, Scheme 69). The thionicotinamide 196 could be obtained from nicotinamide 195 by heating in pyridine with P4S10. 

When Rudolph and Fromm used thionicotinamide adenine dinucleotide (thio-DPN) as an alternate substrate for NAD+ and varied the concentration of ethanol with liver alcohol dehydrogenase [following the reaction at 342 nm, the isosbes-tic point for thio-DPN and reduced thio-DPN (thio-DPNH)], they saw what appeared to be concave upward reciprocal plots with partial substrate inhibition in the presence of thio-DPN (38). However, the asymptote intercepts appeared to decrease with increased thio-DPN concentration, which is not what the above equations predict for a case where a minimum is present in the curve. There must have been other interactions that caused the substrate inhibition by ethanol in the presence of thio-DPN. 

Nicotinamide (34) and structurally related 51 compounds were subjected to the halting activity bioassay to elucidate the structure-activity relationships [105]. The highest activity was recorded in thionicotinamide (35) followed by pyrazinamide (36) and nicotinamide (34). Nicotinamide adenine dinucleotide (NAD) (oxidized form), nicotinamide adenine dinucleotide phosphate (NADP) (oxidized form), (3-nicotinamide mononucleotide (oxidized form) showed halting activity at ca. 10"7 M... 

Figure 28 Electrokinetic separation of the niacin derivatives in the presence of SDS. Conditions applied voltage, 15 kV sample injection, injected by raising the positive end of the capillary about 4 cm higher than the other end capillary, a polyimide-coated fused-silica (70 cm X 50 xm i.d.) micellar solution, 0.15 M SDS in 0.02 M borate-0.01 M KOH (pH 9.1) detection wavelength, 210 nm. 1, Isonicotinic acid hydrazide 2, Nam 3, pyri-dine-3-methanol 4, 6-AN 5, MNA 6, pyridine-3-aldehyde 7, pyridine 8, 3-acetylpyri-dine 9, thionicotinamide 10, NiA 11, pyridine-3-sulfonic acid 12, P-picoline 13, nicotinic acid ethyl ester. (From Ref. 71.)...

Acetylp3rridine- DPN and pyridine-3-aldehyde- DPN are not effective in meeting the DPN requirement 194)- Recently in our laboratory, Dr. Talmadge has been able to show that thionicotinamide- DPN will promote the growth of H. influenzae when present together with levels of DPN which are considerably below the amount required for growth. 

Useful products are also obtained by oxidizing alkyl and aryl pyridyl sulphides. With hydrogen peroxide, 2-methylthiopyridine and 6-methyl-thionicotinamide give the sulphoxides, and perbenzoic acid produces the sulphoxide from 2-benzylthiopyridine <. Hydrolysis of the dibromide from 2-pyridyl sulphide gives the sulphoxide" . More commonly the oxidation of... 

Many apoenzymes react with NAD analogs, too. These are compounds in which the amide group of the pyridine part has been replaced by some other group. Thus nicotinic acid, 3-acetyl-pyridine (with a —COCH3 group), and thionicotinamide (with —CS— NHj) can be coupled to give pyridine nucleotides, all of which are reduced enzymically. These compounds have achieved importance in several studies of reaction mechanism and in distinguishing different apoenzymes. 

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