context advanced glycation end-products (ages) are signaling proteins associated to several vascular and neurological complications in diabetic and non-diabetic patients. ages proved to be a marker of negative outcome in both diabetes management and surgical procedures in these patients. the reported role of ages prompted the development of pharmacological inhibitors of their effects, giving ri...

Betulonic acid belongs to the pentacyclic triterpenic derivative class and can be obtained through the selective oxidation of betulin. In this study we set obtaining several functionalized derivatives of this compound by its condensation with several amino compounds such as aminoguanidine, hydroxylamine, n-butylamine and thiosemicarbazide as our goal. The functionalization of the parent compoun...

Long-lived structural proteins, collagen and elastin, undergo continual non-enzymatic crosslinking during aging and in diabetic individuals. This abnormal protein crosslinking is mediated by advanced glycation end products (AGEs) generated by non-enzymatic glycosylation of proteins by glucose. The AGE-derived protein crosslinking of structural proteins contributes to the complications of long-t...

Protection against diabetic nephropathy (DN) is one of the main targets in diabetes treatment and present study evaluates the nephroprotective effect of Carica papaya L. in streptozotocin (STZ) induced diabetic rats. DN rats were treated with 1.5 and 2.5 gm/dl C. papaya leaf extract for 6 weeks to determine its nephroprotective effect with different parameters. Pimagedine (1 ml/mg) served as a ...

A short review on cardiotonic steroids and their analogues is presented. The natural, semisynthetic and synthetic derivatives, as well as their mechanism of action and structure-activity relationships are shown, with a special reference to aminoguanidine derivatives.

1. Using protein-separative chromatographic procedures and assays specific for putrescine oxidase and spermidine oxidase, adult bovine serum was found to contain a single polyamine-degrading enzyme with substrate preferences for spermidine and spermine. Apparent Km values for these substrates were approx. 40 microM. The apparent Km for putrescine was 2 mM. With spermidine as substrate, the Ki v...

A water-soluble and low-molecular-weight fraction (SB) was obtained from tomato paste. The effects of SB on the formation of advanced glycation end-products (AGE) in protein glycation were studied by the methods of specific fluorescence, ELISA and a Western blot analysis, using the anti-AGE antibody after incubating protein with sugar. The results suggest that SB had strong inhibitory activity,...

It is established that aminoguanidine (AG) is a metabolism-based inactivator of the three major isoforms of nitric-oxide synthase. AG is thought to be of potential use in diseases, such as diabetes, where pathological overproduction of NO is implicated. We show here that during the inactivation of neuronal nitric-oxide synthase (nNOS) by AG that the prosthetic heme is altered, in part, to disso...

The reaction of indole derivatives with cyanoacetic acid followed by treatment with DMFDMA gave the intermediate indolyl enaminonitriles (3). Further reaction with aminoguanidine yielded 5 ́-cyanomeridianin analogues (4). The same intermediate reacted with pmethoxyphenylhydrazine to give the pyrazolyl derivative (8). Treatment of (2E)-3-dimethylamino-2-(1H-indol-3-yl)-propenoate (3a) with hydrox...

The guanidine-II (mini-ykkC) riboswitch is the smallest of the guanidine-responsive riboswitches, comprising two stem loops of similar sequence. We have solved high-resolution crystal structures of both stem loops for the riboswitch from Gloeobacter violaceus. The stem loops have a strong propensity to dimerize by intimate loop-loop interaction. The dimerization creates specific binding pockets...