Search

Chirality is a fundamental and ubiquitous property of nature involved in multiple fields of science. In particular, the possible resolution of the enantiomeric forms of a molecule is crucial in the pharmaceutical, food, and agrochemical industries. The search for efficient, broad-spectrum, and yet simple methods for obtaining enantiomerically pure substances is a current challenge. Enantioselective resolution methods rely on an asymmetric environment that allows the two antipodes of a chiral molecule to be distinguished. In addition to enantiomeric separation techniques, such as chromatography and electrophoresis, new promising approaches involving out-of-the-scheme synergistic effects between chiral selectors (CS) and external stimuli are emerging. This Trends article discusses different enantioselective mechanisms triggered by unconventional physicochemical stimuli for the design of avant-garde approaches that could offer novel perspectives in the field of chiral resolution. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B (HB) is a worldwide public health problem affecting around 250 million people. Only about 10% of people with HB are aware that they are infected. Vaccination is crucial to prophylactically controlling HB and the combination of vaccination and HB immune globulin (HBIG) are essential in preventing disease after exposure to the HB virus. Objectives: In this article, a caprylate-chromatography process has been used for the production of HBIG (HBIG-C). The previously used solvent-detergent process produced an HBIG (HBIG-S/D) with an excellent safety profile but allowed the retention of some procoagulant plasma proteins. The present studies were conducted to assess the character and purity of HBIG produced by the caprylate-chromatography process. Design and Methods: Several analytical methods (eg, chromatography, immunoassays, and nephelometry) were used to assess the molecular characteristics, purity and HBIG potency and specific activity of HBIG-C. In addition, testing was conducted to assess the levels of several pro-coagulant factors. HBIG-C was compared with HBIG-S/D and other immunoglobulins manufactured by the S/D process. Results: The analysis of HBIG-C showed that the product was almost entirely IgG (99.3 ± 0.2% by electrophoresis) and that the residual IgA was less than that found in S/D products. The IgG present in HBIG-C was 99.7 ± 0.6% monomers and dimers as measured by size exclusion chromatography. Aggregates and fragments constituted < 1%. The IgG subclass distribution in HBIG-C was in the normal reference range. Coagulation factor impurities and pro-coagulant activity were reduced in HBIG-C compared to IgG prepared by the S/D method. Conclusions: HBIG-C takes advantage of long-established donor selection processes combined with recently improved manufacturing processes to produce a safe and effective HBIG-product. HBIG-C combines high purity with reduced pro-coagulant factors in a product used for post-exposure prophylaxis of HB. [ABSTRACT FROM AUTHOR]

Background and Aim: Penicillinase plays diverse roles, such as inducing drug resistance by hydrolyzing the amide bond of beta-lactam factors, the metabolism of cephalosporin-attached prodrugs, as well as the metabolism of some antibiotics, and renal clearance. The present study aimed to evaluate the optimum conditions for extracting and purifying penicillinase enzyme. The enzyme source was Bacillus licheniformis 6346 obtained from the Iranian Research Organization for Science and Technology. Materials and Methods: B. licheniformis was cultured in a medium containing mineral salts, nitrogen compounds and carbon sources. Following the harvesting and preparation of bacterial suspension, the destruction of the bacterial cell wall and crude cell extraction was completed using a combination of lysozyme and weak ultrasonication. Afterward, enzyme amount was determined utilizing chromatography and electrophoresis. Furthermore, the optimum growth temperature and incubation time were assessed based on the absorbance of samples at 240 nm, enzyme activity, aerification intensity optimization, enzyme production time, and optimum pH. Results: Approximately 8 g of cells were retrieved in one liter of culture. The optimum pH was determined as 6.5. The heat stability evaluation of the enzyme at different times revealed that the enzyme was stable for more than 1 h at 20°C-45°C, while it is inactivated in 10 min at 60°C. Moreover, the best incubation time for this bacterium was obtained as 9 h at 30°C. In terms of aerification intensity, the highest enzyme production rate of 2394 U/mL was achieved in a 250 mL Erlenmeyer flask with a 50 mL culture medium at 200 RPM. More aerification led to the inhibitory effect of oxygen and reduced enzyme activity. Conclusion: Our findings showed that the bacterium B. licheniformis 6346 can be used for producing penicillinase enzyme in optimum conditions (30°C, 200 RPM, and pH: 6.5). [ABSTRACT FROM AUTHOR]

Oversulfated chondroitin sulfate (OSCS), a non-natural sulfated glycosaminoglycan, recognizes as a significant containment in the pharmaceutical heparin, and it could trigger adverse reactions. Chromatography-, electrophoresis-, electrochemistry-, and spectroscopy-related techniques are currently available for accurate and precise analysis of a trace amount of OSCS in heparin. Recently, emerging studies focus on developing colorimetric and fluorescent probes to monitor OSCS containments in heparin. Therefore, this current review aims to describe the sensing principle and procedure of the reported probes that are sensitive and selective toward OSCS in heparin without the interferences of other sulfated glycosaminoglycans. The reported OSCS-specific probes are comprehensively discussed according to the recognition elements of OSCS, including coralyne, AG73 peptides, positively charged tetraphenylethene derivatives, polythiophene polymer, and poly-L-lysine, protamine, superpositively charged green fluorescent proteins, and poly (diallyldimethylammonium chloride). The sensing of OSCS in heparin is generally achieved using, (i) the specific affinity of the recognition element with OSCS and heparin, (ii) heparinase-mediated hydrolysis of heparin, and (iii) OSCS-induced inhibition of heparinase activity. Additionally, coralyne-based DNA probes can detect OSCS in heparin in the presence of Ca2+ ions without the assistance of heparinase. This review will pave the way to design another sensing probe towards other sulfated contaminants, like dermatan sulfate. [ABSTRACT FROM AUTHOR]