Title: Djenkolic Acid
CAS Registry Number: 498-59-9
CAS Name: S,S¢-Methylenebis-L-cysteine
Additional Names: 3,3¢-(methylenedithio)dialanine; 3,3¢-methylenedithiobis(2-aminopropanoic acid); L-cysteine thioacetal of formaldehyde
Molecular Formula: C7H14N2O4S2
Molecular Weight: 254.33
Percent Composition: C 33.06%, H 5.55%, N 11.01%, O 25.16%, S 25.22%
Line Formula: CH2[SCH2CH(NH2)COOH]2
Literature References: An amino acid isolated from the djenkol bean (Pithecolobium lobatum Benth., Leguminosae): van Veen, Hyman, Rec. Trav. Chim. 54, 493 (1935). Synthesis from 1 mol formaldehyde and 2 mols L-cysteine in strong HCl solution: Armstrong, du Vigneaud, J. Biol. Chem. 168, 373 (1947); cf. du Vigneaud, Patterson, ibid. 114, 633 (1936); Middlebrook, Phillips, Biochem. J. 41, 218 (1947). Synthesis of homologs: Frankel, Gertner, J. Chem. Soc. 1960, 898.
Properties: Rosettes of needles of various lengths. Gradually dec between 300 and 350°. [a]D20.5 -65.0° (1.0N HCl); [a]D25 -47.5° (c = 2 in 1.0N HCl). Very sparingly sol in cold water. Soly in boiling water about 1 in 200. Readily sol in aq solns of alkalies or acids.
Optical Rotation: [a]D20.5 -65.0° (1.0N HCl); [a]D25 -47.5° (c = 2 in 1.0N HCl)
Derivative Type: Monohydrochloride
Molecular Formula: C7H14N2O4S2.HCl
Molecular Weight: 290.79
Percent Composition: C 28.91%, H 5.20%, N 9.63%, O 22.01%, S 22.05%, Cl 12.19%
Properties: Slender prisms, dec 250-300°. Sol in water.
Derivative Type: Dibenzoyldjenkolic acid
Molecular Formula: C21H22N2O6S2
Molecular Weight: 462.54
Percent Composition: C 54.53%, H 4.79%, N 6.06%, O 20.75%, S 13.86%
Properties: Crystals, mp 87.5-89°.
Melting point: mp 87.5-89°
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