Chemical Synthesis of Benzamide Adenine Dinucleotide:  Inhibition of Inosine Monophosphate Dehydrogenase (Types I and II)

Abstract

Treatment of 3-(2,3-O-isopropylidene-beta-D-ribofuranosyl)benzamide (6) with POCl3 in (EtO)3-PO afforded only little phosphorylation product (8, 5%), but the major product was 5'-chlorobenzamide riboside (7, 85%). Reaction of 6 with 2-cyanoethyl N,N-diisopropylchlorophosphoramidite followed by 2-cyanoethanol/tetrazole treatment and oxidation with tert-butyl peroxide gave a 1:1 mixture of the desired 5'-O-bis(2-cyanoethyl) phosphate 9 and the chloro derivative 7. This mixture was treated with methanolic ammonia and partitioned between CHCl3 and water. The 2',3'-O-isopropylidenebenzamide mononucleotide (8) was obtained in 21.2% overall yield from the aqueous layer. Compound 8 was then converted into the corresponding imidazolide 11b which, upon coupling with 2',3'-O-acetonide of AMP, afforded the acetonide of benzamide adenine dinucleotide (15) in 94% yield together with small amounts of symmetrical pyrophosphates P1,P2-bis(2',3'-O-isopropylideneadenosin-5'-yl)pyrophosphate (13, 3%) and P1,P2-bis(2',3'-O-isopropylidene-3-(carbamoylphenyl)-5'-ribosyl)py rophosphate (14, 2%). Deprotection of 15 with Dowex 50/H+ in water afforded the desired benzamide adenine dinucleotide (BAD) in 93% yield. BAD inhibits inosine monophosphate dehydrogenase type I (IC50 = 0.78 microM) and type II (IC50 = 0.88 microM) with same degree of potency.

Inhibitors of inosine monophosphate dehydrogenase as potential chemotherapeutic agents

“…Thus, thiophenfurin (18), and selenophenfurin (19) were found to be as potent as the parent compounds [17,18]. Similarly, benzamide riboside (21) showed high toxicity at nanomolar concentrations in S49.1 lymphoma cells [19].…”

“…In contrast, 21 was converted into benzamide adenine dinucleotide (25, BAD) as efficiently as tiazofurin into TAD. Later, BAD (K i = 0.8 µM) was synthesised and found to be a little less active than TAD (K i = 0.1 µM) [21]. C-nucleoside NAD analogues, C-NAD (26, IC 50 = 7 µM) and C-PAD (27, IC 50 = 26 µM), showed relatively good inhibitory activity against IMPDH.…”

Synthesis and Cytotoxicity Evaluation of Phosphorylated Derivatives of Ribavirin

“…All solvents used for spectroscopy and other physical studies were reagent grade and were further purified by literature methods. 23 Melting points were determined using a calibrated thermometer by Guna Digital Melting Point apparatus. Infrared spectra (IR) were recorded as potassium bromide (KBr) discs on a Nicolet 380 FT-IR spectrophotometer.…”

Rehab of NAD(P)-Dependent Enzymes with NAD(P)-Based Inhibitors

“…A key issue in designing a suitable drug for inhibition of InhA would be to construct a tight binding analogue of the adduct that is metabolically stable. In order to address glycosyl bond instability, we replaced the nicotinamide ring nitrogen with carbon to provide benzamide adenine dinucleotide (BAD or 1-deaza-NAD) with a stable C-C glycosyl linkage [47]. We then prepared the 4-phenoxy-BAD analogue, Fig.…”