1. Effect of DL-penicillamine on the aorta of growing chickens. Ultrastructural and biochemical studies
I Pasquali Ronchetti, C Fornieri, E Caselgrandi, M Baccarani Contri, D Quaglino Jr Am J Pathol . 1986 Sep;124(3):436-47.
The effect of DL-penicillamine on the architecture of the aortic wall of growing chickens was studied, with particular attention to elastin and collagen. Penicillamine was added to the diet (0.2% and 0.4%, in the presence or not of 10 mg/kg CuSO4 and 100 mg/kg vitamin B6) from hatching, for periods from 7 days up to 2 months. The same regions of the thoracic aortas were examined and compared in all the different experimental conditions. The results showed that penicillamine induced relevant modifications in the process of elastin fibrogenesis. The alterations consisted of an increase of elastin in the extracellular space, associated with an increase in the number of elastin fibers per unit area, and a decrease of the mean profile area of the fibers. Interestingly, penicillamine induced the formation of numerous bundles of microfibrils associated or not with elastin fibers. After prolonged treatment, elastin tended to diminish and the fibers tended to fuse into polymorphic syncytia. Collagen fibrils were larger, showed more heterogeneous cross diameters, were less numerous, and were more spread out within the tissue. All the other components of the aortic wall appeared not to be altered by the chemical. Penicillamine did not modify the copper content of chick aortas, whereas it induced a 40-50% reduction of the activity of both salt and 4 M urea-soluble peptidyl lysyl oxidases in the same tissue. These data may help in understanding some of the pathologic manifestations in human beings during D-penicillamine treatment.
2. Analytical and preparative enantioseparation of DL-penicillamine and DL-cysteine by high-performance liquid chromatography on alpha-acid glycoprotein and beta-cyclodextrin columns using ninhydrin as a reversible tagging reagent
Ravi Bhushan, Rajender Kumar J Chromatogr A . 2009 Apr 10;1216(15):3413-7. doi: 10.1016/j.chroma.2009.02.015.
Two sulfur-containing amino acids, DL-cysteine (Cys) and DL-penicillamine (PenA), were condensed with ninhydrin to form their spirothiazolidine derivatives. These were separated by HPLC using alpha-acid glycoprotein (AGP) and beta-cyclodextrin (beta-CD) columns. The resolution conditions were optimized and the results were compared. Since the method provided resolution greater than 2 it was also applied to preparative separation. After separation, each of them was detagged using Zn dust and 10% aqueous trifluoroacetic acid. For analytical purposes dinitrophenyl (DNP) derivatives of DL-Cys and DL-PenA were also prepared and were resolved on both the columns. The detection was carried out using photodiode array detection system at 231 nm. The limits of detection were found to be 0.01% and 0.004% for spirothiazolidine carboxylic acid and DNP derivatives, respectively.
3. Enantioresolution of dl-penicillamine
Ravi Bhushan, Rajender Kumar Biomed Chromatogr . 2010 Jan;24(1):66-82. doi: 10.1002/bmc.1355.
Penicillamine (PenA) is a nonproteinogenic amino acid containing a thiol group. The three functional groups in penicillamine undergo characteristic chemical reactions and differ in their ability to participate in various chemical and biochemical reactions. d-penicillamine is more active pharmacologically, while the l-isomer occurs 'naturally'. This review deals with the enantioresolution of PenA both by direct and indirect methods using liquid chromatography. HPLC separation of its diastereomers prepared with different chiral derivatizing reagents (on reversed-phase columns) and separation of the derivatives prepared with achiral reagents (on chiral columns or via ligand exchange mode) has been discussed. Separation of enantiomers tagged with achiral reagent (to add a chromophore for ehanced detection) when there is no diastereomer formation has been considered separately. In addition, application of PenA and its derivatives as chiral selector for enentioresolution of certain other compounds has also been discussed.