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Hallucinogens, CNS Stimulants, And Cannabis
Published in S.J. Mulé, Henry Brill, Chemical and Biological Aspects of Drug Dependence, 2019
Little is known specifically about these neutral compounds in human pharmacology, but studies have been made on the many amination products that are easily derived from them chemically, and to a large measure they have proven to be active as psychotomimetics.50 The mechanism of action of intoxication of the essential oils is completely unclear, but it has been shown that at least one of the group of essential oils, safrole, is not converted to an amphetamine, but to one of several tertiary amino-methylenedioxypropiophenones.51 If these are proven to be centrally active, they well may account for the chemistry of plant oil intoxication.
Biology of microbes
Published in Philip A. Geis, Cosmetic Microbiology, 2006
Other more common mechanisms for assimilating nitrogen are ammonia incorporation and assimilatory nitrate reduction. Ammonia is easily incorporated into amino acids by forming the alanine amino acid directly by amination of pyruvate using the alanine dehydrogenase enzyme. Alternatively, a cell can form glutamate (an amino acid) by aminating α-ketoglutarate (a TCA cycle intermediate) using the glutamate dehydrogenase enzyme. Once these two amino acids have been formed, the ammonia they carry (now called an α-amino group) can be transferred to other carbon skeletons of other catabolic intermediates by transamination to form several other amino acids.
Asymmetric Reduction of C=N Bonds by Imine Reductases and Reductive Aminases
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Matthias Höhne, Philipp Matzel, Martin Gand
The discovery of reductive aminases is an important milestone to render enzymatic reductive amination reactions more efficient (Aleku et al., 2016). After RedAms of fungal origin (e.g., from Aspergillus oryzae), were discovered, researchers also identified enzymes in the bacterial sequence space that are able to utilize the nucleophile amines at a low stoichiometric excess (Roiban et al., 2017; France et al., 2018). AspRedAm shows a broad substrate scope as revealed by screening with a photometric assay, and amine and carbonyl substrates fall into different categories (Fig. 14.13), according on their reactivities. Figure 14.10 gives an overview about typical amines that AspRedAm can synthesize. From this study, the following trends can be summarized: Preferred substrates are aldehydes and cyclohexanone on the side of carbonyls and propargyl- and allylamine as nucleophiles. Their combination allows the reductive amination to proceed to 80–95% conversion even when only 1 equivalent of the amine nucleophile is employed. Activities range up to 6–8 U/mg and are thus 10-fold higher compared to reactions with, e.g., employing S. ipomoeae IRED in reductive aminations. However, many of these best-performing reactions yield non-chiral products.Based on the crystal structure (Aleku et al., 2017), active site mutants of AspRedAm yielded variants with improved or even inverted enantiopreference.Combinations of preferred substrates yielding chiral amines such as 67 and rasagiline 71/72 by methylamination of 2-hexanone, or amination of 2-tetralone with propargylamine require a 2–5 fold excess of the amine.Most of the remaining substrate combinations that lead to interesting amine products still require large excess of amines (20–50×), which is comparable to employing IREDs for reductive amination.A few bacterial reductive aminases have been found (France et al., 2018; Roiban et al., 2017). They offer a few complementary reductive aminations, e.g., the (R)-selective conversion of p-fluorophenylacetone and propargylamine to the secondary amine 75.Substrate reactivities for the reductive aminase from Aspergillus oryzae. Adapted from Aleku et al. (2017).
Pharmacokinetics, metabolism and off-target effects in the rat of 8-[(1H- benzotriazol-1-yl)amino]octanoic acid, a selective inhibitor of human cytochrome P450 4Z1: β-oxidation as a potential augmenting pathway for inhibition
Published in Xenobiotica, 2021
John P. Kowalski, Robert D. Pelletier, Matthew G. McDonald, Edward J. Kelly, Allan E. Rettie
8‐{[(4,5,6,7‐2H4)‐1H‐1,2,3‐benzotriazol‐1‐yl]amino}octanoic acid (8-BOA-d4) was synthesized using a modified protocol from our previous study and has been summarized in Figure S1. The additional step, amination of benzotriazole-d4, was performed analogous to a previously reported method (Campbell and Rees 1969). Accurate mass was determined via UPLC-MS on a Waters Acquity UPLC (Milford, MA) coupled to an AB Sciex TripleTOF 5600 mass spectrometer (Framingham, MA). 1H NMR spectra was recorded at 25 °C in deuterated chloroform on a 499.73 MHz Agilent DD2 (Santa Clara, CA) spectrometer. Purity as determined by 1H NMR spectroscopy was ≥95%. 1H NMR (500 MHz, Chloroform-d) δ ppm 3.42 (t, J = 7.09 Hz, 2 H), 2.35 (t, J = 7.34 Hz, 2 H), 1.59–1.69 (m, 2 H), 1.54 (quin, J = 7.21 Hz, 2 H), 1.40–1.49 (m, 2 H), 1.31–1.38 (m, 4 H). HRMS (ESI+) m/z [M + H]+ calculated (C14H17D4N4O2) 281.1910, observed 281.1909, δ ppm 0.4.The 1H NMR spectrum for 8-BOA-d4 has been provided in Figure S2(A) and the 1H NMR spectrum for 8-BOA has been provided in Figure S2(B) for a comparison (reproduced from Kowalski et al.2020 with the authors’ permission).
Biofilm-encapsulated nano drug delivery system for the treatment of colon cancer
Published in Journal of Microencapsulation, 2020
Jinyan Shi, Zhiwei Ma, Hao Pan, Yang Liu, Yuqi Chu, Jinglei Wang, Lijiang Chen
The zeta potentials of MSN, MSN-NH2, MSN-HA, MSN-5-FU, OMVs and OMVs-NPs were measured by Malvern Zetasizer. As shown in Table 1, the zeta potentials of MSN and MSN-NH2 were −21.50 ± 4.61 mVand +1.65 ± 0.11 mV respectively. The zeta potential of mesoporous silica indicated a favourable modification in the latter step. The positive potential of the zeta potential demonstrated the success of amination. Moreover, the potential of MSN-HA changed to −29.27 ± 0.57 mV when HA molecule was modified on the surface of MSN. The zeta potential of OMVs-MSN-5-FU was closer to the OMVs, which proved that the composite vector can be successfully prepared by co-extrusion. These changes of zeta potential indirectly confirmed the successful synthesis of MSN, MSN-NH2, MSN-HA and OMVs-NPs.
Novel methods in glycomics: a 2019 update
Published in Expert Review of Proteomics, 2020
Wei-Qian Cao, Ming-Qi Liu, Si-Yuan Kong, Meng-Xi Wu, Zheng-Ze Huang, Peng-Yuan Yang
Reductive amination is the most commonly used reducing end derivation method. Most fluorescent labeling methods are based on reductive amination, such as 2-aminobenzoic acid (2-AA), 2-aminobenzamide (2-AB), 2-amino-N-(2-aminoethyl)-benzamide (AEAB), 2-aminoacridone (2-AP), 2-aminopyridine (PA), 2-aminonaphthalene trisulfonic acid (ANTS), 1-aminopyrene-3,6,8-trisulfonic acid (APTS) labeling, and procainamide labeling [34,88–94]. Procainamide labeling has shown to significantly improve sensitivity compared to 2-AB, and greatly reduce the fucose migration in MS/MS analysis [94]. In addition to fluorophores, some highly hydrophobic reagents and positively charged reagents are also used to improve N-glycan signaling [77,95,96]. For example, a recent study reported a new method termed glycan reductive amino acid coded affinity tagging (GRACAT) to increase nearly ionization efficiency by 50-fold [97]. It is worth mentioning that reductive amination requires high concentrations of label and reducing agent, resulting in the need for a workup step. It is difficult to recover very small glycan quantities (i.e. less than one microgram) from reductive amination. Moreover, methods take advantage of the fact that glycans released by PNGaseF have a reducing end amino group have advantages over reductive amination. Thus, the Waters Rapifluor N-glycan labeling kit is a fine choice for labeling and recovery of small glycan quantities.