Enzymatic hydrolysis of stereoregular oligodeoxyribonucleoside phosphorothioates (PS-oligos) synthesized via the oxathiaphospholane method has been used for assignment of their diastereomeric purity. For this purpose, two well-known enzymes of established diastereoselectivity, nuclease P1 and snake venom phosphodiesterase (svPDE) have been used. However, because of some disadvantageous properties of svPDE, a search for other [Rp]-specific endonucleases was undertaken. Extracellular bacterial endonuclease isolated from Serratia marcescens accepts PS-oligos as substrates and hydrolyzes phosphorothioate bonds of the [Rp] configuration, whereas internucleotide [Sp]-phosphorothioates are resistant to its action. Cleavage experiments carried out with the use of unmodified and phosphorothioate oligonucleotides of different sequences demonstrate that the Serratia nuclease is more selective in recognition and hydrolysis of oligodeoxyribonucleotides than previously reported. The substrate specificity exhibited by the enzyme is influenced not only by the nucleotide sequence at the cleavage site but also by the length and base sequence of flanking sequences. The Serratia nuclease can be useful for analysis of diastereomeric purity of stereodefined phosphorothioate oligonucleotides, but because of its sequence preferences, the use of this enzyme in conjunction with svPDE is more reliable.
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http://dx.doi.org/10.1089/oli.1.1999.9.171 | DOI Listing |
J Org Chem
December 2024
Chemistry and Materials Program, College of Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Kohto-ku, Tokyo 135-8548, Japan.
Both enantiomers of 2-ethylquinazolin-4-ones bearing -CHO/CDO and CHO/CHO phenyl groups at the N3 position were prepared. These are isotopic atropisomeric compounds based on a remote and conformationally flexible H/D and C/C discrimination, and it was found that a CHCl solution of -CHO/CDO derivative shows a slight specific optical rotation. Furthermore, diastereomeric quinazolinone derivatives bearing a chiral carbon were prepared, and their stereochemical purities and rotational stability as well as the isotopic atropisomerism were verified by H NMR and chiral high-performance liquid chromatography (HPLC) analyses.
View Article and Find Full Text PDFAmino Acids
December 2024
Scientific and Production Center "Armbiotechnology" of NAS RA, 14 Gyurjyan Str, 0056, Yerevan, Armenia.
A synthesis of new enantiomerically enriched derivatives of (S)-α-aminopropionic acid, containing in the β-position 1,2,3-triazole groups coupled with a o-, m- and p-substituted phenyl residue, was developed based on Cu(I) catalyzed [3 + 2] cycloaddition of azides with alkynes. As the starting materials was used the square-planar Ni(II)complex of the Schiff base of propargylglycine with the chiral auxiliary BPB (Benzylprolylbenzophenone) and 1,4-substituted phenyl azides. The assignment of the (S)-absolute configuration of the α-carbon atom of the amino acid residue of the main diastereomeric complexes of the cycloaddition products was carried out on the basis of positive Cotton effects in the region of 480-580 nm of the circular dichroism spectra.
View Article and Find Full Text PDFChem Sci
September 2024
State Key Laboratory of Chemical Biology and Drug Discovery, Research Institute for Future Food, Department of Food Science and Nutrition, The Hong Kong Polytechnic University Hung Hom Hong Kong China
A novel approach for efficient synthesis of chiral C,O-chelated BINOL/gold(iii) complexes by diastereomeric resolution using enantiopure BINOL as a chiral resolving agent was demonstrated. The BINOL/gold(iii) diastereomers with different solubility were separated by simple filtration, providing optically pure BINOL/gold(iii) complexes with up to >99 : 1 dr. By combining this with an efficient BINOL ligand dissociation process, a simple and column-free method for chiral resolution of racemic gold(iii) dichloride complexes on a gram scale was established, affording their enantiopure forms in good yields.
View Article and Find Full Text PDFBiomed Chromatogr
December 2024
Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667, India.
TLC is used globally, yet less attention has been paid to TLC (in enantioseparation) despite its advantages. The present paper describes/reviews successfully practiced direct approaches of 'chiral additive in achiral stationary phase' (as an application of in-home thought out, prepared, tested, and modified chiral stationary phase), 'pre-mixing of chiral reagent with the enantiomeric mixture' (an approach using both achiral phases during chromatographic separation) and 'chiral additive in mobile phase', and chiral ligand exchange for enantioseparation of DL-amino acids, their derivatives, and some active pharmaceutical ingredients. It provided efficient enantioseparation, quantitative determination, and isolation of native forms via in-situ formation of non-covalent diastereomeric pair.
View Article and Find Full Text PDFOrg Biomol Chem
July 2024
Chair of Industrial Organic Chemistry and Biotechnology, Faculty of Chemistry, Bielefeld University, Universitätsstr. 25, 33615, Bielefeld, Germany.
Besides its native biological function as a plant hormone, -(+)-12-oxo-phytodienoic acid (12-OPDA) serves as a metabolite for the cellular formation of (-)-jasmonic acid and has also been shown to have an influence on mammalian cells. In order to make this biologically active, but at the same time very expensive natural product 12-OPDA broadly accessible for further biological and medicinal research, we developed an efficient bioprocess based on the utilization of a tailor-made whole-cell catalyst by following the principles of its biosynthesis in nature. After process optimization, the three-step one-pot synthesis of 12-OPDA starting from readily accessible α-linolenic acid could be conducted at appropriate technically relevant substrate loadings in the range of 5-20 g L.
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