Recent progress in the development of immobilized penicillin G acylase for chemical and industrial applications: A mini‐review

Immobilized penicillin G acylase (PGA) as an important industrial catalyst can catalyze penicillin G potassium (PG) to 6‐aminopenicillanic acid (6‐APA). 6‐APA is an important intermediate for semisynthetic penicillin drugs, which occupies a huge market space in the anti‐inflammatory field; as a result, immobilized PGA occupies a huge market space in the pharmaceutical field. However, at present, there are different degrees of defects in the preparation and production process of immobilized PGAs on the market because of the huge demand; therefore, the performance of immobilized PGA and its productivity will bring huge economic benefits to enterprises. Therefore, research on immobilized PGA has always been a focus. This review first introduces the source, classification, structure, and catalytic mechanism of PGA and then studies the development of immobilization methods, immobilized carriers, reaction media, enzyme activity regeneration, and reactors of immobilized PGA in recent years.     

A Novel Hybrid Metal–Organic Framework–Polymeric Monolith for Solid‐Phase Microextraction

This study describes the fabrication of a novel hybrid metal–organic framework– organic polymer (MOF–polymer) for use as a stationary phase in fritless solid‐phase microextraction (SPME) for validating analytical methods. The MOF–polymer was prepared by using ethylene dimethacrylate (EDMA), butyl methacrylate (BMA), and an imidazolium‐based ionic liquid as porogenic solvent followed by microwave‐assisted polymerization with the addition of 25 % MOF. This novel hybrid MOF–polymer was used to extract penicillin (penicillin G, penicillin V, oxacillin, cloxacillin, nafcillin, dicloxacillin) under different conditions. Quantitative analysis of the extracted penicillin samples using the MOF–organic polymer for SPME was conducted by using capillary electrochromatography (CEC) coupled with UV analysis. The penicillin recovery was 63–96.2 % with high reproducibility, sensitivity, and reusability. The extraction time with the proposed fabricated SPME was only 34 min.     

Simultaneous Determination of Procaine Penicillin G and Benzathine Penicillin G by Second Derivative Spectrophotometry

Abstract

A new method for determining the binary mixtures of procaine penicillin G and benzathine penicillin G using “zero-crossing” second derivative spectrophotometry is described. Calibration graphs were linear up to 8.80 10^?5 M for procaine penicillin G and 4.40 10^?5 M for benzathine penicillin G. The method was realized in ethanol/water medium (30 % v/v). A complete and exhaustive statistical analysis of the experimental data was realized to demonstrate the validity of method. The method was applied for determining procaine penicillin G and benzathine penicillin G synthetic mixtures with good results. The procedure does not require any separation step.     

Cinnamoylacetanilides and Their Metal Chelates

A new series of β-ketoanilides, in which the keto group attached to an olefinic linkage, have been synthesized by the reaction of acetoacetanilide with p-substituted benzaldehydes (4-methoxybenzaldehyde, 4-ethoxybenzaldehyde, 4-dimethylaminobenzaldehyde and 4-nitrobenzaldehyde) under specified conditions. The existence of these β-ketoanilides predominantly in the intramolecularly hydrogen bonded enol forms has been well demonstrated from their IR, ¹H NMR and mass spectral data. Details on the formation of [ML₂] complexes of these compounds with Ni(II), Cu(II) and Zn(II) and their nature of bonding were discussed on the basis of analytical, IR, ¹H NMR and mass spectral data.     

青霉素裂解液的高效液相色谱分析

 利用高效液相色谱法分析测定青霉素裂解液中的主要成分 6 氨基青霉烷酸 (6 APA)、青霉素G钾和苯乙酸 ,并对副产物青霉噻唑酸进行了液相色谱的定性检测。结果表明 ,实验方法简便、快速 ,结果准确 ,可以用于 6 APA生产的质量控制。     

免疫纳米金催化氯金酸与羟胺反应-共振散射光谱检测痕量青霉素G

小粒径的金和免疫金纳米粒子对氯金酸-盐酸羟胺这一反应具有较强的催化作用,其产物在580 nm处有一共振散射峰。以半抗原青霉素G为模型,用粒径为9 nm的金纳米微粒标记羊抗兔青霉素噻唑蛋白抗体制备了青霉素G的免疫纳米金共振散射光谱探针。在pH5.4的柠檬酸-磷酸氢二钠缓冲溶液中,青霉素G与金标兔抗青霉素发生特异性结合生成胶体金免疫复合物,离心分离。取适量金标羊抗兔青霉素的上层清液做催化剂,在pH3.36盐酸-柠檬酸钠缓冲溶液－40μg/mL氯金酸－21.6μg/mL的盐酸羟胺条件下,进行催化反应后金纳米粒径增大,在580nm共振散射强度处增强。随着青霉素G浓度c增大,上层清液中免疫金纳米微粒数量降低,I580nm值降低。其降低值△I580nm与c在0.15-225 ng/mL范围内成线性关系,其回归方程为△I580nm=0.28c+5.16,检出限为0. 05 ng/mL。该法用于牛奶中青霉素G的检测,结果较好。     

Determination of Procaine Penicillin G and Penicillin G by Second Derivative Spectrophotometry in Pharmaceutical Products

Abstract

“Zero-crossing” derivative spectrophotometry has been used for determining binary mixtures of penicillin G and procaine penicillin G.

The procedure is rapid, simple, nondestructive, and does not require resolutions of equations.

Calibration graphs are linear between 2.0 and 50.0 μg mL^?1 of the penicillin G at 226.0 nm, and between 2.0 and 100.0 μg mL^?1 of procaine penicillin G at 319.0 nm, in the presence of each other. A complete and exhausive statistical analysis of the experimental data was realized to demonstrate the validity of method. The method was successfully applied to assay commercial injections of these drugs.     

Synthesis of a calix[4]crown modified with germanium‐containing side chains

A germacalix‐crown, 25,27‐bis[1‐(3‐trimethylgermylpropyl)oxy]calix[4]arene‐crown‐6, 1,3‐alternate ( 1a ), and its carbon analog, 25,27‐bis‐[1‐(4,4‐dimethylpentyl)oxy]calix[4]arene‐crown‐6, 1,3‐alternate ( 1b ), were prepared and their structures were confirmed by elemental analysis and ¹H and ¹³C NMR spectroscopy. A cation transport test indicated that both compounds exhibited much the same cation transport ability, so that the role of the germanium moiety in capturing and transporting counteranions is not yet clear. Copyright © 2005 John Wiley & Sons, Ltd.     

Quantum chemical study of penicillin: Reactions after acylation

The density functional theory methods were used on the model molecules of penicillin to determine the possible reactions after their acylation on β‐lactamase, and the results were compared with sulbactam we have studied. The results show that, the acylated‐enzyme tetrahedral intermediate can evolves with opening of β‐lactam ring as well as the thiazole ring; the thiazole ring‐open products may be formed via β‐lactam ring‐open product or from tetrahedral intermediate directly. Those products, in imine or enamine form, can tautomerize via hydrogen migration. In virtue of the water‐assisted, their energy barriers are obviously reduced. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007     

铁氰化钾高灵敏共振瑞利散射法测定青霉素类抗生素

在稀HCl介质中,K3[Fe(CN)6]与阿莫西林(AMO)、氨苄西林(AMP)、氯唑西林钠(CLO)、羧苄西林钠(CAR)和青霉素钠(BEN)等抗生素药物在加热条件下反应生成结合产物,会导致溶液的共振瑞利散射(RRS)强度急剧增强,并产生新的RRS光谱,5种反应产物的最大散射峰均位于330 nm附近。在一定的浓度范围内,不同的反应体系散射强度(∆I)与药物浓度成正比,反应具有很高的灵敏度,K3[Fe(CN)6]对5种药物的检出限分别在4.61至5.62 ng·mL-1之间。本文研究了RRS的光谱特征和适当的反应条件,并讨论了反应机理和散射增强的原因,还考察了共存物质的影响,表明方法具有较好的选择性,可用于胶囊、片剂和人血清及尿液中青霉素类药物的测定。     

Synthesen und Eigenschaften von Bis(perfluoralkyl)zink‐Verbindungen

Syntheses and Properties of Bis(perfluoroalkyl)zinc Compounds The conditions for the syntheses of bis(perfluoroalkyl)zinc compounds Zn(R_f)₂ · 2 D (R_f = C₂F₅, n‐C₃F₇, i‐C₃F₇, n‐C₄F₉, n‐C₆F₁₃, n‐C₇F₁₅, and n‐C₈F₁₇; D = CH₃CN, tetrahydrofurane, dimethylsulfoxide) are described. Mass spectra, thermal decompositions, ¹⁹F‐ and ¹³C‐NMR spectra are discussed.     

Complexation of selenium to (R)‐Rh2(MTPA)4: thermodynamics and stoichiometry

Variable‐temperature ¹H and ⁷⁷Se NMR data for 3‐phenylselenenyl‐1‐phenyl‐1‐propene (1) in the presence of Rh₂(MTPA)₄ (Rh*) prove that the equilibria are strongly shifted towards the adduct Rh*···1; free selenide molecules cannot be detected as long as uncomplexed rhodium atoms are available. In the case of excess Rh*, both 1 : 2 and 1 : 1 adducts (Rh* vs 1) are formed, and the latter is slightly favoured. With excess selenide, the system strongly favours the complexation of two selenide molecules (1 : 2 adduct), i.e. one at each rhodium atom. In this situation, intermolecular selenide exchange can be monitored by variable‐temperature ¹H NMR spectroscopy and the energy barrier is estimated to be 54–55 kJ mol^?1. Copyright © 2001 John Wiley & Sons, Ltd.     

Bioengineering functional copolymers. III. Synthesis of biocompatible poly[(N‐isopropylacrylamide‐co‐maleic anhydride)‐g‐poly(ethylene oxide)]/poly(ethylene imine) macrocomplexes and their thermostabilization effect on the activity of the enzyme penicillin G acylase

Stimuli‐responsive poly[(N‐isopropylacrylamide‐co‐maleic anhydride)‐g‐poly(ethylene oxide)]/poly(ethylene imine) macrobranched macrocomplexes were synthesized by (1) the radical copolymerization of N‐isopropylacrylamide and maleic anhydride with α,α′‐azobisisobutyronitrile as an initiator in 1,4‐dioxane at 65 °C under a nitrogen atmosphere, (2) the polyesterification (grafting) of prepared poly(N‐isopropylacrylamide‐co‐maleic anhydride) containing less than 20 mol % anhydride units with α‐hydroxy‐ω‐methoxy‐poly(ethylene oxide)s having different number‐average molecular weights (M_n = 4000, 10,000, or 20,000), and (3) the incorporation of macrobranched copolymers with poly(ethylene imine) (M_n = 60,000). The composition and structure of the synthesized copolymer systems were determined by Fourier transform infrared, ¹H and ¹³C NMR spectroscopy, and chemical and elemental analyses. The important properties of the copolymer systems (e.g., the viscosity, thermal and pH sensitivities, and lower critical solution temperature behavior) changed with increases in the molecular weight, composition, and length of the macrobranched hydrophobic domains. These copolymers with reactive anhydride and carboxylic groups were used for the stabilization of penicillin G acylase (PGA). The conjugation of the enzyme with the copolymers significantly increased the thermal stability of PGA (three times at 45 °C and two times at 65 °C). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1580–1593, 2003     

Dissipation and residue determination of penicillin G and its two metabolites in citrus under field conditions by DSPE/UPLC–MS/MS

A rapid determination method of residual penicillin G and its two metabolites in citrus was developed and validated by dispersive solid-phase extraction and ultra-high performance liquid chromatography–tandem mass spectrometry (DSPE/UPLC–MS/MS). The samples were extracted with 80% acetonitrile and purified with octadecylsilane. High linearity was obtained with correlation coefficients (r²) >0.9981. The limits of quantification were 0.005–0.01 mg/kg. The recoveries of penicillin G and its metabolites spiked in blank citrus were within 76.7–107%, with relative standard deviations of 1.3–9.6%. The dissipation dynamics and distribution of penicillin G in citrus followed first-order kinetics, with half-life of 1.7–2.7 days. Penicillin G degraded easily in citrus and the metabolite was mainly penilloic acid, which can exist stably for long time. The terminal residues of penicillin G in pulp, whole citrus and peels were 0.015–0.701, 0.047–7.653 and 0.162–13.376 mg/kg, respectively. The hazard indexes for risk assessment of citrus were significantly <1, suggesting that the health risks to humans after consumption of citrus were insignificant and negligible. These results could provide necessary data for evaluating the safe and proper use of penicillin G in citrus.     

The engineering and immobilization of penicillin G acylase onto thermo‐sensitive tri‐block copolymer system

In this work, the relationships between catalytic performances of penicillin G acylase (PGA) and the molar ratio of carrier, thermo‐sensitive tri‐block polymer, poly (N,N‐diethylacrylamide‐b‐ β‐hydroxyethyl methacrylate‐b‐glycidyl methacrylate) (PDEA‐b‐PHEMA‐b‐PGMA) were studied firstly, and result documented the optimal molar ratio was n_DEA:n_HEMA:n_GMA = 100:47:24, which presented a suitable lower critical solution temperature (LCST) of 35°C and the activity retention ratio of 80.62% (±0.50%). Based on the suitable carrier, immobilization conditions were investigated and optimized. When pH of solution, concentration of PGA, immobilized time, and immobilization temperature were 8.0, 1/10 (m/v), 16 hours, and 36°C, respectively, enzyme loading capacity (L), enzyme activity (Ea), and activity retention ratio (Ar) of PGA arrived at the highest value of 21 223 U, 16 199 U/g, and 93.50% (±0.50%), respectively. Besides, the response rate (Rr) of immobilized PGA was the same as free PGA, the reusable stability (Rs) was 77.00% (±1.00%) after using for 11 times, which indicated that the carrier has better compatibility with L, Ar, Rs, and Rr.     

Semi-Empirical and DFT Studies on Structures and Spectra for C78（CH2）2

Eighteen possible isomers of C78（CH2）2 weTe investigated by the INDO method. It was indicated that the most stable isomer was 42,43,62,63-C78（CH2）2, where the -CH2 groups were added to the 6/6 bonds located at the same hexagon passed by the longest axis of C78 （C2v）, to form cyclopropane structures. Based on the most stable four geometries of C78（CH2）2 optimized at B3LYP/3-21G level, the first absorptions in the electronic spectra calculated with the INDO/CIS method and the IR frequencies of the C-C bonds on the carbon cage computed using the AM1 method were blue-shifted compared with those of C78 （C2v） because of the bigger LUMO-HOMO energy gap and the less conjugated carbon cage after the addition. The chemical shifts of ^13C NMR for the carbon atoms on the added bonds calculated at B3LYP/3-21G level were moved upfield thanks to the conversion from sp^2-C to sp^3-C.     

Total synthesis of a novel 2-thiabicyclo[3.2.0]heptan-6-one analogue of penicillin N

A route has been developed which allows synthesis of novel cyclobutanone analogues of penicillin. This is illustrated by the synthesis of (1R,4R,5R,5′R,7S)-(1b) and (1S,4S,5S,5′R,7R)-7-[5′-amino-5′-carboxy]pentanamido]-2-thiabicyclo[3.2.0]heptan-6-one-4-carboxylate (1a), an analogue of penicillin N. The key steps in the synthesis were the formation of the bicyclic structure via a [2+2] cycloaddition and the introduction of nitrogen at C7 via an intramolecular nitrene insertion.     

Dicoumarol complexes of Cu(II), Fe(II) and Fe(III): preparation,characterization, in‐vitro antibacterial and DNA binding activity

3‐3′‐Benzylidenebis[4‐hydroxycoumarin] or 4‐nitro,3‐3′‐benzylidenebis[4‐hydroxycoumarin] or 4‐methoxy,3‐3′‐benzylidenebis[4‐hydroxycoumarin] and their complexes with Cu(II), Fe(II) and Fe(III) were synthesized and characterized using ¹H‐NMR, ¹³C‐NMR, IR spectra, electronic spectra, magnetic measurements and elemental analyses. The ligands, metal salts, complexes, control and standard drug were tested for their in‐vitro antibacterial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi, and Serratia marcescens. The metal complexes exhibit good activity against bacterial strains compared with parental compounds and moderate compared with the standard drug (ciprofloxacin). In‐vitro DNA‐binding activity was carried out using agarose gel electrophoresis. The synthesized compounds show effective DNA‐binding activity. Copyright © 2007 John Wiley & Sons, Ltd.     

青霉素类药物的共振光散射光谱分析

本文研究了青霉素钠-碱性品红缔合物的共振散射光谱,建立了pH =7.5的C-L缓冲溶液中,共振光散射法测定青霉素钠的新方法.线性回归方程△IRu=1.74+5.17C,相关系数R=0.9981,检测限3.16×10-7mol/L.该方法简单快速,灵敏度高,对实际样品进行了测定,得到了令人满意的结果.     

Comparative Electrochemical and Spectroscopic Studies of I‐Motif‐forming DNA Nonamers

The paper shows the structural diversity of cytosine (C)‐rich oligodeoxynucleotides (ODNs) arising from their detail nucleotide sequence and experimental conditions. In slightly acidic solutions, the ODN nonamers with different adenine (A) and cytosine (C) sequences can adopt non‐canonical structures involving protonated bases. A distinct secondary structure formed in (C)‐rich sequences, called i‐motif (iM), consists of hemiprotonated and intercalated cytosine base pairs (C.C⁺). Folding and unfolding of particular structures in solutions were monitored by ¹H NMR and CD spectroscopies and native polyacrylamide gel electrophoresis (PAGE), which are capable to determine their structural characteristics. Effects of sequences and their proclivity to formation of the iM on electrochemical behaviour of the ODN nonamers were studied by electrochemical methods. The LSV signals of A and C obtained from the reductive dissolution of ODN adsorption layers on a hanging mercury drop electrode were processed by elimination voltammetry with linear scan (EVLS), which revealed complex effects of the nonamer properties (namely their primary and secondary structure confirmed in solution) on their adsorption and reduction activity.