DIMETHYLARSINOUS ACID ESTERS OF 1-THIO- AND -SELENOGALACTOSE. A NEW CLASS OF POTENTIAL CARCINOSTATIC AGENTS

Trithioarsenites [(RS)3As], dithioarsonites [R-As(SR′)2] and thioarsinites [R2As-SR′]: Preparations, chemical, biochemical and biological properties

Contrary to P(V) compounds, As(V) compounds can very easily reduced by thiols to As(III) thiolates that are deemed to play a central role in the metabolism of arsenic and therefore a review on the preparation and properties of the title thiolates can be of interest. The preparation of trithioarsenites, dithioarsonites and thioarsinites involves reactions of a thiol with a proper As(V) or As(III) precursor via 4-centered transition states or a thiolate by SN2 mechanisms. Convenient precursors are the solids As2O3, arsonic and arsinic acids, although for the latter two acids the separation of the product from the co-produced disulfides can be problematic. Only a few crystal structures have been reported and involve only trithioarsenites. From their chemical properties, the hydrolyses, transthiolations and air oxidations are of particular interest from mechanistic and biochemical/biological points of view. Their nucleophilicity towards alkyl halides and acyl derivatives revealed unexpected behavior. Although these molecules have many free electron pairs only three reports were found pertaining to their reaction with metal cations (Hg2+) and metal carbonyls; the mercuric complexes being not characterized. Only a few studies appeared for the action of the title compounds towards enzymes, while the patent literature revealed that they have bactericidal, fungicidal and insecticidal activities for agricultural applications, some have antiparasitic activity on animals and a few are carcinostatic.

Synthesis of S-dialkylarsino-3-mercapto-1,2-propanediols and evaluation of their anticancer activity

Some new S-dialkylarsenic compounds, S-dialkylarsino-3-mercapto-1,2-propanediol (3a-3d) and their derivatives (4a,4b), have been synthesized. They were screened at the National Cancer Institute (NCI) for their anticancer activity against a panel of about 60 human tumor cell lines. Most of them display anticancer activity having GI(50) and LC(50) values at low concentrations and are sensitive to leukemia, renal cancer and prostate cancer cell lines and in which the compound 3c is the most active.

Synthesis and biodistribution of radioarsenic labeled dimethylarsinothiols: derivatives of penicillamine and mercaptoethanol

Arsenic analogs of sulfhydryl containing biomolecules can be derived from dimethylchloroarsine as a precursor. Arsenic-76 labeled dimethylarsinothiols (dimethylarsinopenicillamine and dimethylarsinomercaptoethanol) were synthesized, purified by chromatography, and their biodistributions obtained in mice. The present study demonstrates the possibility of developing a group of radioarsenicals from SH-containing biomolecules.