Hydrolytic Enzymes for the Synthesis of Pharmaceuticals
Peter Grunwald in Pharmaceutical Biocatalysis, 2019
Microbial epoxide hydrolases (EHs) catalyse the addition of one molecule of water to epoxides, allowing their hydrolysis for the formation of the corresponding vicinal diols (Widersen et al., 2010; Bala and Chimni, 2010). The EH from Candida viswanathii has been reported to be an effective enzyme for the non-selective hydrolysis of 2-(phenoxymethyl)oxirane to form the racemic 3-phenoxy-1,2-propanediol, which is a useful precursor of β-adrenoblockers, cardiovascular drugs and anti-bacterial agents, among others (Meena and Banerjee, 2010). Whole cell form of the microorganism provided over 90% conversion after 15 h at 30°C using a mixture of a buffer pH 7 and ethanol (Scheme 9.16). Hydrolysis of 2-(phenoxymethyl)oxirane with a whole cell EH from Candida viswanathii
Hits and Lead Discovery in the Identification of New Drugs against the Trypanosomatidic Infections
Venkatesan Jayaprakash, Daniele Castagnolo, Yusuf Özkay in Medicinal Chemistry of Neglected and Tropical Diseases, 2019
In recent years, naphthoquinone has drawn much attention as a scaffold with potential antitrypanosomatidic activity. Carneiro et al. (2012) reported the synthesis of new oxirane derivatives using naphthoquinones as starting materials. Even though most of the synthesized compounds proved more active than the reference drug benznidazole (IC50 = 11.5 μM, CC50 = 48 μM) against epimastigote forms of T. cruzi, only compound 27 (Figure 14) exhibited comparable cytotoxicity (IC50 = 0.09 μM, CC50 = 44 μM). Structure of the most active oxirane derivative 27.
Organic Chemicals
William J. Rea, Kalpana D. Patel in Reversibility of Chronic Disease and Hypersensitivity, Volume 4, 2017
Ethylene (oxirane, methyl): Ethylene is one of the most common substances in breath analysis. Ethylene can be formed directly from crude oil (Figure 5.1). Ethylene oxide is used as a sterilizing solution for a number of types of medical equipment. Numerous adverse effects, including death, resulting from ethylene oxide exposure have been reported in the literature.97,98 One episode of contamination with resultant fatalities occurred during the sterilization of the heart lung machines used for babies. Ethylene gas is used to ripen bananas and other fruits artificially. Many chemically sensitive cannot tolerate fruit ripened artificially but have no problem with naturally ripened fruit. Ethylene at times has been used as a fungicide. Ethylene is also used as a dispersant in coating composition for silicone crucibles and also as a blending fuel for enhancement of cold start performance of gasoline and ethanol.
Effect of different salivary glucose concentrations on dual-species biofilms of Candida albicans and Streptococcus mutans
Published in Biofouling, 2021
Arella Cristina Muniz Brito, Isis Morais Bezerra, Maria Heloisa de Souza Borges, Yuri Wanderley Cavalcanti, Leopoldina de Fátima Dantas de Almeida
The specimens were prepared using an acrylic resin based on PMMA (TDV®, Brazil) with polymerizable acrylic liquid, heat cured type (TDV®, Brazil), according to the manufacturer's instructions. The resin during the plastic phase was deposited in a metal mold, and polymerization was carried out for 60 min at 100 °C. Then, the specimens (20 × 100 mm) were polished with abrasive sandpaper (400 and 600) in a polishing machine (Arotec®, São Paulo, Brazil) (Santana et al. 2013; Cavalcanti et al. 2014), and the mean surface roughness was determined (5.30 ± 3.94 µm) on a profilometer (CCI MP, Taylor Hobson, England) for specimen allocation in 24-compartment plates. The measurements were made at two different points of the specimen, with an increase of 20 × (WD = 4.7 mm), considering the measurement standards xyz (512 × 512 pixels) with a speed of 3×. The specimens were sterilized in ethylene oxide.
Study of biodistribution and systemic toxicity of glucose functionalized SPIO/DOX micelles
Published in Pharmaceutical Development and Technology, 2019
Nussana Thitichai, Chalaisorn Thanapongpibul, Man Theerasilp, Witaya Sungkarat, Norased Nasongkla
DOX was purchased from Vesino Industrial Co., Ltd. (Tianjin, China). Hydrophobic SPIO was prepared using the same protocol as previously described (Sun et al. 2004). A mouse fibroblast cell line, L929, was obtained from the Japanese Collection of Research Bioresources Cell Bank, Japan. Cells were grown in the Roswell Park Memorial Institute (RPMI) 1640 medium supplemented with 10% of fetal bovine serum (FBS; Biochrom GmbH, Germany), and 1% of a penicillin-streptomycin solution (10,000 U/mL; Gibco™, Invitrogen, USA) at 95% relative humidity in a 5% CO2 incubator at 37 °C. 3–(4,5-Dimethyl-thiazol-yl)-2,5-diphenyltetrazlium bromide (MTT) was purchased from Molecular Probes™ (Invitrogen, USA). Toluene, sodium chloride, tetrahydrofuran (THF), NaOH, and concentrated hydrochloric acid (37% wt. in H2O) were acquired from Sigma-Aldrich. For allyl-poly(ethylene glycol) (PEG) synthesis, the chemical reagents were 18-crown-6, naphthalene, and potassium chucks from Sigma-Aldrich. 3-Buten-1-ol was dried by stirring over calcium hydride for 5 days and distilled in an atmosphere of dry argon. Ethylene oxide was stored in a gas tank. Anhydrous dimethyl sulfoxide (DMSO) was dried by stirring over calcium hydride for 3 days and was distilled under dry argon. Other analytical reagent grade chemicals were supplied by NanoPolyPEG, Co., Ltd., and the BioNEDD laboratory.
How close are we to definitively identifying the respiratory health effects of e-cigarettes?
Published in Expert Review of Respiratory Medicine, 2018
Alexsandra Ratajczak, Wojciech Feleszko, Danielle M. Smith, Maciej Goniewicz
Given the risk of lung cancer linked with the use of tobacco cigarettes, the potential net public health benefit of e-cigarette use as a cancer prevention tool has been discussed [51,52]. However, given the multiple potential etiologic mechanisms related to incident case development coupled with the long latency period in developing illness, there is currently no definitive evidence to commenting on the role of e-cigarettes in increasing lung cancer risk or in their ability to aid in net population reduced risk of incident cases. As an intermediate assessment, cross-sectional biomarker data can be suggestive of possible carcinogen exposures related to cancer development; however, these studies are certainly not causal links and are subject to a number of limitations. For instance, Shahab et al. [53] examined a large panel of biomarker data among e-cigarette users, cigarette users, and users of both products (‘dual users’). The e-cigarette-only users had significantly lower metabolite levels for TSNAs, particularly the 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a metabolite of potent lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanon (NNK). Several observational longitudinal studies also showed a substantial reduction in exposure to NNK and several VOCs, including respiratory toxicants like acrolein, acrylamide, acrylonitrile, 1,3-butadiene (human carcinogen), and ethylene oxide among smokers who switched to e-cigarette [54–56].
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