Mass Spectrometric Analysis
Adorjan Aszalos in Modern Analysis of Antibiotics, 2020
Mass spectrometry was used in an interesting study on the biosynthesis of isopenicillin N from the tripeptide LLD-ACV [239]. The precursor was synthesized with 17O and 18O enrichment in the α- and δ-carboxyl groups of the α-amino adipic acid residue. The protonated molecular ion region (using desorption CI) of isopenicillin N showed no loss of labeled oxygen from the precursor during conversion by the cell-free extract of Cephalosporiumacremonium. Also, when the conversion of unlabeled precursor was carried out in the presence of water enriched with 17O and 18O no incorporation of labeled oxygen was detectable. These experiments preclude the possibility of this conversion involving a hydration-dehydration step, as proposed by others.
The role of lifestyle factors in recurrent implantation failure
Efstratios M. Kolibianakis, Christos A. Venetis in Recurrent Implantation Failure, 2019
Both oocytes and sperm are susceptible to the environmental influences, which can subsequently affect embryo development.9,10 Nutrition and other factors originating from the environment can adversely influence maternal health, the intrauterine milieu, and, possibly, maternal response to the implanting embryo.11 It has been recently proposed that women with RIF have a different metabolic status compared with women who have highly receptive endometria.12 RIF has been associated with higher levels of serum glucose and altered levels of the metabolites related to energy, amino acid, and lipid metabolism, suggesting a possibility of metabolic dysfunction.12 At the endometrial level, impaired glucose uptake has been implicated in abnormal decidualization, poor implantation, and pregnancy loss,13 whereas normal glucose metabolism was associated with successful decidualization.14 Certain lifestyle factors such as smoking, alcohol, and obesity are known to induce chronic oxidative stress, which has been extensively linked with reproductive dysfunction on oocyte, tubal, and endometrial levels.15 Elevated levels of adipic acid, a by-product metabolite of reactive oxygen species (ROS) has been detected in the circulation of women with RIF, indicating that women with RIF have an increased oxidative stress state, and the condition can be possibly linked with environmentally induced oxidative damage.12
Introduction to the organic acidemias
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop in Atlas of Inherited Metabolic Diseases, 2020
Dicarboxylic aciduria is also a prominent result of the intake of medium-chain triglyceride which is found increasingly in infant formulas. 5-Hydroxyhexanoate may serve as a clue, but other medium-chain dicarboxylic acids, adipic, suberic and sebacic are found. Large quantities of adipic acid are found in the urine of children eating gelatin.
Ficus carica extract impregnated amphiphilic polymer scaffold for diabetic wound tissue regenerations
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Jia Feng, Yu Niu, Yi Zhang, Hong Zuo, Shujin Wang, Xufeng Liu
Polymerization of xylitol, adipic acid and l-glutamic acid was carried out by the polycondensation reactions with the previous report's slightly modified procedure [28]. The 1:1:1 stoichiometric ratio of xylitol, adipic acid, l-glutamic acid monomers is accurately weighed 1 g and dissolved in a 1:1 ratio of DD water–ethanol solution, and these solutions were made up to 20 mL. The solutions were then taken in an RB flask to heat 120 °C with constant stirring (150 rpm) for 5 h to get a transparent solution of the PXAG prepolymer. The transparent solution was heated in a micro oven at 150 W for about 10 min to form the pale yellow solution of PXAG polymers. The polymer viscosity was elevated slowly with the cumulative reaction period. Finally, the PXAG polymeric solution was kept a room temperature (25 °C) for 24 h to get a solid palm leaves structure of PXAG copolymer. The formation of palm leaves structure polymer of PXAG polymer, which has an ester bond between the monomers of xylitol and adipic acid and the amide bonds between adipic acid and l-glutamic acid monomers (Scheme 1), was confirmed by FT-IR, 1H and 13C NMR spectroscopy. The synthetic procedure of PXAG synthesis is shown in Supplementary Figure 1.
Synthetic biodegradable polyesters for implantable controlled-release devices
Published in Expert Opinion on Drug Delivery, 2022
Jinal U. Pothupitiya, Christy Zheng, W. Mark Saltzman
PCL can be synthesized from CL or 6-hydroxyhexanoic acid, which are both intermediates in the oxidation of cyclohexanol to adipic acid in microorganisms. Polycondensation of 6-hydroxyhexanoic acid to yield PCL requires harsh temperature and pressure conditions in the absence of catalysts [126]. The polymerization is feasible in the presence of catalysts at low temperatures; however, PCL formation proceeds sluggishly. ROP of CL is the preferred route to produce PCL. CL is commercially produced from the oxidation of cyclohexanone and subjected to ROP to yield high molecular weight PCL. ROP allows for fine tuning of molecular weight and produces polymers with low polydispersity in molecular weight; the polydispersity, or polydispersity index (PDI), is defined as the ratio of weight average molecular weight (Mw) and the number average molecular weight (Mn), PDI = Mw/Mn [126].
Assessment of cyclohexanone toxicity in inhalation-exposed F344 rats and B6C3F1 mice: applications in occupational health
Published in Inhalation Toxicology, 2018
Cheol Hong Lim, Yong Hoon Lee, Yong Soon Kim, Hyun Sung Choi, Dong Seok Seo
Cyclohexanone is an important chemical in the manufacture of adhesives, sealant chemicals, agricultural chemicals, paint and coating additives, solvents, electrical and electronic products, paints and coatings, photography supplies, film, and photo-chemicals, and as an intermediate in nylon production (NCBI, MSDS of cyclohexanone). Although cyclohexanone and cyclohexanol are used in some organic solvents, they are mostly used as raw materials to obtain adipic acid or capro-lactam. Cyclohexanol is converted into cyclohexanone by the dehydrogenation reaction with the Cu-based catalyst, and cyclohexanone is formed following several stages of purification. The manufacturing process is as follows:
Related Knowledge Centers
- Carboxylate
- Dicarboxylic Acid
- Ester
- Nylon
- Organic Compound
- Chemical Formula
- E Number
- Food Additive
- Cyclohexanone
- Cyclohexanol