Past,present and future of cyanide antagonism research:From the early remedies to the current therapies

This paper reviews milestones in antidotal therapies for cyanide(CN) spanning early remedies,current antidotal systems and research towards next generation therapies.CN has been a part of plant defense mechanisms for millions of years.It became industrially important in the nineteenth century with the advent of CN assisted gold mining and the use of CN as a pest control agent.The biochemical basis of CN poisoning was actively studied and key mechanisms were understood as early as 1929.These fundamental studies led to a variety of antidotes,including indirect CN binders that generate methemoglobin,direct CN binders such as hydroxocobalamin,and sulfur donors that convert CN to the less toxic thiocyanate.Research on blood gases at the end of the twentieth century shed new light on the role of nitric oxide(NO) in the body.The discovery of NO's ability to compete with CN for enzymatic binding sites provided a previously missed explanation for the rapid efficacy of NO generating antidotes such as the nitrites.Presently used CN therapies include:methemoglobin/NO generators(e.g.,sodium nitrite,amyl nitrite,and dimethyl aminophenol),sulfur donors(e.g.,sodium thiosulfate and glutathione),and direct binding agents [(e.g.,hydroxocobalamin and dicobalt salt of ethylenediaminetetraacetic acid(dicobalt edetate)].A strong effort is being made to explore novel antidotal systems and to formulate them for rapid administration at the point of intoxication in mass casualty scenarios.New antidotes,formulations,and delivery systems are enhancing bioavailability and efficacy and hold promise for a new generation of improved CN countermeasures.

Combined effect of microwave and hydrothermal treatment on anti-nutritional factors,antioxidant potential and bioactive compounds of plum(Prunus domestica L.)kernels

The effect of microwave heating(450 W for 6 min),hydrothermal treatment(45℃ for 6,9,12 h)and their combination on antioxidant potential,anti-nutritional factors,and phenolic compounds of plum kernels were studied.Amygdalin and hydrocyanic acid content were reduced to undetectable amounts,while the phytic acid and tannins were reduced to 89.50 and 84.71%,respectively,when combined effects of microwave and hydrothermal(45℃ for 12 h)treatments were employed.Antioxidant activity and phenolic content were higher in microwave treated samples than hydrothermal and combined treatments.HPLC results revealed that combined treated samples have considerable amounts of phenolic compounds,particularly gallic acid,chlorogenic acid,(+)-catechin,syringic acid,rutin,3,4-dihydroxy benzoic acid,tannic acid,and quercetin.

Conjugate Hydrocyanation of Chalcone Derivatives Using Ethyl Cyanoacetate as an Organic Cyanide Source

The conjugate hydrocyanation of chalcone derivatives using ethyl cyanoacetate as an organic cyanide source at room temperature under open air and transition metal-free conditions was described. The protocol has advantages of using relatively cheap, less toxic, stable and easy-to-handle cyanating reagent, high yield, and mild reaction condi- tion.

Asymmetric Syntheses Aided by Biocatalysts

This article summarizes the achievements of the authors' group in the area of biocatalyst catalyzed organic reactions in recent 10 years. A strain of Geotrichum sp. obtained by screening is capable of stereoselectively reducing a number of carbonyl compounds. In many cases, the stereochemistry is complementary with that obtained by baker's yeast. Therefore, this micro organism provides a useful pathway to the preparation of alcohol compounds with specific configurations. On the other hand, a number of plant sources have been screened for oxynitrilases and the hydrocyanation reactions of various arylcarboxaldehydes have been investigated. A “micro aqueous reaction system' was invented, by which a series of novel optically active cyanohydrins were prepared. On this basis, a high through put continuous reaction system has been designed. This paper also describes examples of the syntheses of bio active compounds by using the optically active compounds obtained from the above mentioned catalytic reactions as precursors.

Hydrocyanation of Unsaturated Imines Using Potassium Hexacyanoferrate(Ⅱ) as a Cyanide Source

An efficient method for the hydrocyanation of unsaturated imines to synthesizeβ,γ-unsaturatedα-aminonitriles by a one-pot two-step procedure using potassium hexacyanoferrate(Ⅱ)as a cyanide source and benzoyl chloride as a promoter under catalyst-free condition is described.The advantages of this protocol are the use of a nontoxic,nonvolatile and inexpensive cyanating agent,no use of transition metal catalysts,high yield and simple work-up procedure.