Hydrolytic reactivity trends among potential prodrugs of the O2-glycosylated diazeniumdiolate family. Targeting nitric oxide to macrophages for antileishmanial activity.

Glycosylated diazeniumdiolates of structure R 2NN(O)NO-R' (R' = a saccharide residue) are potential prodrugs of the nitric oxide (NO)-releasing but acid-sensitive R 2NN(O)NO (-) ion. Moreover, cleaving the acid-stable glycosides under alkaline conditions provides a convenient protecting group strategy for diazeniumdiolate ions. Here, we report comparative hydrolysis rate data for five representative glycosylated diazeniumdiolates at pH 14, 7.

Experimental evidence for enzyme-enhanced coupled motion/quantum mechanical hydrogen tunneling by ketosteroid isomerase.

Although there are considerable data demonstrating that quantum mechanical hydrogen tunneling (HT) occurs in both enzymatic and nonenzymatic systems, little data exist that address the question of whether enzymes enhance the amount of HT relative to the corresponding nonenzymatic reactions. To investigate whether 3-oxo-Delta (5)-steroid isomerase (ketosteroid isomerase, KSI) enhances HT relative to the nonenzymatic (acetate-catalyzed) isomerization of Delta (5)-androstene-3,17-dione ( 1) to Delta (4)-androstene-3,17-dione ( 3), alpha-secondary deuterium kinetic isotope effects (KIE) at C-6 of the steroid were determined for both the KSI- and acetate-catalyzed isomerizations. The normal intrinsic secondary KIE for both wild type (WT) KSI (1.

Synthesis, nitric oxide release, and anti-leukemic activity of glutathione-activated nitric oxide prodrugs: Structural analogues of PABA/NO, an anti-cancer lead compound.

Diazeniumdiolate anions and their prodrug forms are reliable sources of nitric oxide (NO) that have generated interest as promising therapeutic agents. A number of structural analogues of O(2)-(2,4-dinitro-5-(4-(N-methylamino)benzoyloxy)phenyl) 1-(N,N-dimethylamino)diazen-1-ium-1,2-diolate (PABA/NO), an anti-cancer lead compound that is designed to release NO upon activation by glutathione, were prepared. The nitric oxide release patterns of these O(2)-(2,4-dinitrophenyl) diazeniumdiolates in the presence of glutathione were tested and it was found that in the absence of competing pathways, these compounds release nearly quantitative amounts of NO.

PABA/NO as an anticancer lead: analogue synthesis, structure revision, solution chemistry, reactivity toward glutathione, and in vitro activity.

PABA/NO is a diazeniumdiolate of structure Me(2)NN(O)=NOAr (where Ar is a 5-substituted-2,4-dinitrophenyl ring whose 5-substituent is N-methyl-p-aminobenzoic acid). It has shown activity against human ovarian cancer xenografts in mice rivaling that of cisplatin, but it is poorly soluble and relatively unstable in water. Here we report structure-based optimization efforts resulting in three analogues with improved solubility and stability in aqueous solution.