Chiral recognition based on enantioselective interactions of propranolol enantiomers with cyclosophoraoses isolated from Rhizobium meliloti

Abstract

Cyclosophoraoses isolated from Rhizobium meliloti, as an NMR chiral shift agent, were used to discriminate propranolol enantiomers. Continuous variation plot made from the complex of cyclosophoraoses with propranolol showed that the diastereomeric complex had predominantly 1:1 stoichiometry through UV spectroscopic analysis. The chiral recognition of propranolol enantiomers by cyclosophoraoses was investigated through the determination of binding constant based on the (13)C NMR chemical shift changes. The averaged K(obs) values from the plots were 55.7 M(-1) for (R)-(+)-propranolol and 36.6 M(-1) for (S)-(-)-propranolol, respectively. Enantioselectivity (alpha = K(R+)/K(S(-)) of 1.52 was then obtained. Computational calculation also revealed that (R)-(+) propranolol was more tightly bound with cyclosophoraose than (S)-(-)-propranolol due to the enhanced van der Waals interaction.

Preparation of a Novel Chiral Stationary Phase Containing Rhizobial Cyclic β‐(1 → 2) Glucans for the Chiral Separation of Some Flavonoids

“…It has been recently reported that Cys act as complexing agents with a variety of hydrophobic guest molecules, enhancing their solubility in water . In addition, because of their chiral selectivity, Cys molecules are widely used as chiral additives in the separation of enantiomers by capillary electrophoresis method and as chiral stationary phase (CSP) in high‐performance liquid chromatography (HPLC) . Recently, modified cyclodextrins (cyclic α‐1,4‐glycans, CDs) have also been efficiently employed as CSPs in HPLC .…”

Properties and current applications of bacterial cyclic β-glucans and their derivatives

“…Cyclic b-(1,2) glucans (family I) are used in the separation of enantiomers, and the first study reported the chiral discrimination ability on Nacetylphenylalanine, catechin and propranolol using NMR spectroscopy [109,110]. In the enantiomeric interactions, C1 and C2 carbons composed of b glycosidic linkages actively participated.…”

Electrochemical characterization of a glassy carbon electrode modified with microbial succinoglycan monomers and multi-wall carbon nanotubes for the detection of quercetin in an aqueous electrolyte

“…This complexation ability has been taken advantage not only of differentiating one enantiomer from another [24,25] but also of quanti- tatively determining flavonoids [22,23]. However, some carbohydrates derived from microorganisms having unique complex-forming activity other than cyclodextrins for certain reactions have been recently introduced [29,[32][33][34][35], where they functioned as catalysts or chiral selectors for various chemicals. Succinoglycan monomers isolated from a soil microorganism, R. meliloti 2011 are divided into three different structures, M1, M2 and M3, depending on the number of substituent, succinyl group, as shown in Fig.…”