There is overwhelming evidence that meteorites bring a-methylated amino acids to earth with some L(S) enantiomeric excess. How does that get transferred into normal biological molecules? In this brief account, we show that an a-methylated amino acid, D(R)-a-methylvaline, can react with pyruvate and phenylpyruvate salts in dry mixtures to form alanine and phenylalanine with L enantiomeric excess...

This study focused on the identification of suitable lipase or esterase activity for enantiomeric resolution of (R,S)-naproxen. For an economically viable reaction the enantiomeric ratio (E) should preferably be >100, while maximising the conversion will reduce the mass of material that requires racemisation and recycling. Hence the aim was to find an enzyme that yields (S)-naproxen with an ena...

Very slow kinetic evolution (days) of chiral nanoribbons based on amphiphilic molecular assemblies is investigated for various enantiomeric excess.

The use of femtosecond laser pulses to selectively trigger an asymmetric photoreaction is demonstrated in this study. Depending on the handedness of the laser polarization, more R- or S-enantiomers of a racemate are gradually destroyed, leading to the generation of enantiomeric excess. The kinetic evolution of this excess is detected with a sensitive polarimeter. Hence, discrimination between r...

BACKGROUND AND OBJECTIVES To achieve better therapeutic benefits of local anesthetics in the control of postoperative pain through controlled-release carrier. The objective of this study was to compare the characteristics of sensory and motor blockade between microspheres without local anesthetic: racemic bupivacaine-loaded microspheres; 50% enantiomeric excess bupivacaine-loaded microspheres; ...

BACKGROUND AND OBJECTIVES The duration of Local Anesthetic (LA) effects can be expanded by its incorporation into systems of sustained release microspheres. However, the possibility that LA sustained release systems are neurotoxic has not received due attention in literature. The objective of this study was to investigate the effects of pure microspheres of poly(lactic-co-glycolic acid), filled...

The threshold electric field E(th) for a transition from the anticlinic to the synclinic phase of enantiomeric mixtures of the liquid crystal TFMHPOBC was measured as a function of temperature T and enantiomeric excess X. For small X the phase boundary curve on a temperature-electric-field phase diagram exhibits the phase sequence synclinic-anticlinic-reentrant synclinic on decreasing the tempe...

An important property of electromagnetic fields, which arises from the interaction between fields and chiral molecules, is called optical chirality. By enhancing this field property, while maintaining constant input power, we are able to increase absorption of circularly polarized light by chiral molecules of a certain handedness. This enhancement is achieved through the use of achiral plasmoni...