D-Mandelonitrile

Numerous oligosaccharides occur naturally,170 an example being amygdalin (D-mandelonitrile-/3-glucosido-6-/3-D-glucoside) obtained from... 

Sambunigrin (D-mandelonitrile glucoside) from the leaves of the elder tree—Sambucus nigra (Caprifoliaceae)—is isomeric to prunasin. 

Bark contains condensed tannins, prunasin (d-mandelonitrile glucoside) emulsin eudesmic acid (3,4,5-trimethoxybenzoic acid) /i-couma-ric acid scopoletin sugars andothers (karrer). Fruit skin contains capulin anthocyanins. Prunasin is a cyanogenic glucoside that is hydrolyzed by the enzyme prunase into hydrocyanic acid (HCN, prussic acid). 

Note The colors of the chromatogram zones produced by the mandelonitrile glycosides change with time Those of the D-isomers turn steel blue within an hour, while the 1 isomers turn reddish-brown during this time. It is possible to distinguish between D-and L-forms on the basis of these typical color differences and color changes. Both isomeric forms have a dark brown color after about 24 hours. 

Kovacs, M. F. "Dhurrin (p-hydroxy mandelonitrile-B-O-glucoside) An allelopath Identified In johnsongrass (Sorghum halapense (L.) Fers.) rhizome exudates", Ph.D. Thesis. University of Maryland, College Park, MD. 1972. 

Zhu, D., Mukherjee, C., Biehl, E.R. and Hua, L. (2007) Discovery of a mandelonitrile hydrolase from Bradyrhizobium japonicum USDA110 by rational genome mining. Journal of Biotechnology, 129, 645-650. 

Further evidence for the formation of intermediate compounds in catalytic reactions is afforded by the observation (a) that optically active camphor is formed from optically inactive (racemic) camphor carboxylic acid in the presence of the d- or /-forms of quinine, quinidine or nicotine and (6) that optically active bases, e.g., quinidine, catalyze the synthesis of optically active mandelonitrile from benzaldehyde and hydrocyanic acid.10 These results hardly admit of any other interpretation than the intermittent production of a catalyst-reactant compound. 

In the first step of one synthesis of (D,L)-mandelic acid, benzaldehyde (I) is converted to mandelonitrile (II, or benzaldehyde cyanohydrin) ... 

Note. The name iaetrile is frequently used to describe amygdalin but it has also been used to describe /-mandelonitrile-) -glucuronide, a substance which may be derived from amygdalin. 0-(6-0-)5-D-Glucopyranosyl-)S-D-glucopyranosyl)-D-mandelo-nitrile... 

Wajant, H., Roerster, S., Selmar, D., Effenberger, R. and Pfizenmaier, K. (1995) Purification and characterization of a novel (R)-mandelonitrile lyase from the fern Phlebodium aureum. Plant Physiol, 109,1231-8. 

Examples of LLC phases for enzyme stabilization and bio catalysis include the micellar and LLC phases water (or glucose in water)/oclanol/octyl-/3-D-glucoside LLC system for accelerating /3-D-glucosidase-calalyzed hydrolysis of octyl-/ -n-glucoside to form glucose and octanol [108] and the use of LLC phases of numerous commercial surfactants to accelerate the (S)-hydroxynitrile lyase-catalyzed synthesis of (S)-mandelonitrile [109]. 

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