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Chemosensory Disorders and Nutrition
Published in Alan R. Hirsch, Nutrition and Sensation, 2023
Carl M. Wahlstrom, Alan R. Hirsch, Bradley W. Whitman
Pyridine Threshold Tests. On these tests, the ten chefs averaged 11.75 decismells (a standard measurement of smell threshold), better than normal for their age. That the Pyridine Threshold Test scores did not correlate with scores on the Smell Suprathreshold Tests, with or without prompting, may be taken as further evidence that the ability to identify odors, beyond a certain minimal receptor threshold, is independent of odor perception and relies more on a different central nervous system process, namely, memory. It is probably more important for chefs to remember what a particular dish should smell like, than to be able to sense minute amounts of an odorant.
Biochemical Effects in Animals
Published in Stephen P. Coburn, The Chemistry and Metabolism of 4′-Deoxypyridoxine, 2018
Vogel et al.532 included deoxypyridoxine in their comparison between aromatic and nonaromatic compounds as enzyme inhibitors. Deoxypyridoxine hydrochloride, pyridoxine hydrochloride, and pyridoxamine hydrochloride all caused 50% inhibition of carboxypeptidase B at about 7 × 10−5 Mand catalase at 1 × 10”” M. Pyridoxal phosphate was slightly more effective. None of these compounds inhibited carboxypeptidase A or peroxidase. Deoxypyridoxine (1.5 mg/day per mouse) did not affect the response of uterine peroxidase or liver catalase to estrogen. Pressey397 studied the effect of pyridoxine analogs on invertases from potato, Neurospora, and yeast. Pyridoxine and deoxypyridoxine were generally comparable in their inhibitory effect which the author postulates results from the pyridine ring analogous to the effect of aniline, another aromatic base.
Physical Chemistry of Bilirubin: Binding to Macromolecules and Membranes
Published in Karel P. M. Heirwegh, Stanley B. Brown, Bilirubin, 1982
Karel P. M. Heirwegh, Stanley B. Brown
The solubility of bilirubin acid in several solvents has been measured (Figure 3).2 The solubility in apolar media, such as n-hexane, is low, less than 1 µM, and generally increases with solvent polarity, to more than 10 mMin dimethylsulfoxide (DMSO). Aromatic hydrocarbons (benzene) are better solvents than the aliphatic, and an asymmetric structure seems to promote dissolution (toluene, xylene). Pyrrole and pyridine, which are asymmetric aromatic and polar, are good solvents. Dichloromethane and chloroform are asymmetric and are better solvents than carbon tetrachloride. Aliphatic alcohols do not dissolve bilirubin acid, indicating that ability to form hydrogen bonds is not sufficient. Acetone, on the other hand, dissolves some bilirubin, and here again the asymmetric ketones are better solvents. It is interesting to note that increasing chain length does not increase solubility, as illustrated by di-isobutyl ketone which dissolves less bilirubin than methyl isobutyl ketone or acetone. Also, ethyl acetate is a better solvent than long-chain esters, olive oil and lard, which in fact dissolve very little bilirubin.
Discovery of a new class of triazole based inhibitors of acetyl transferase KAT2A
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Roberta Pacifico, Nunzio Del Gaudio, Guglielmo Bove, Lucia Altucci, Lydia Siragusa, Gabriele Cruciani, Menotti Ruvo, Rosa Bellavita, Paolo Grieco, Mauro F. A. Adamo
As a follow up of this work, we have posed the question of whether or not those classes of new compounds may be useful in medicinal chemistry. Triazoles were repeatedly reported as bioactive compounds1–11 and many drug candidates containing the pyridine ring were equally described. Pyridines are commonly used in medicinal chemistry because of their ability to establish hydrogen bonds either as donors or acceptors, their water solubility, small dimensions and, most importantly, their potential to act as amide bioisosteres13. The latter in particular, makes pyridine pivotal in drug discovery14. Additionally, if compared to the benzene ring15–17, the pyridine unit displays a relevant increased basicity18, an improved aqueous solubility19 and a smaller polar surface; 20; all of these features consent an optimal orientation of the pyridine-containing drugs with the biological target through π-stacking interactions21,22. According to the FDA23, there are more than 95 approved drugs containing the pyridine moiety that are, currently, employed against tuberculosis (i.e., isoniazid24,255 and ethionamide266), HIV/AIDS (i.e., delavirdine277), Alzheimer disease (i.e., tacrine288), Raynaud’s syndrome (i.e., nifedipine299), hypertension (e.g., nivaldipine3010) and so on among the others (Figure 1).
Discovery of novel mRNA demethylase FTO inhibitors against esophageal cancer
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Bo Qin, Qian Bai, Dan Yan, Fanxiang Yin, Zhu Zhu, Chaoyuan Xia, Yang Yang, Yi Zhao
1,2,3-Triazole as one of the most important classes of nitrogen-containing heterocycle exhibits potent anticancer activity6. 1,2,3-triazole-benzoxazole hybrid 1 (Figure 1) displayed antiproliferative activity against SKBr3, HepG2, and HeLa cells with IC50 values of 7.1, 11.2, and 6.8 μg/mL7. 1,2,3-Triazole-benzisoxazole hybrid 2 showed antiproliferative activity against MOLM13, MOLM14, and MV4-11 cell lines8. Hybrid 3 inhibited migration and mammosphere formation and induced cell cycle arrest at G2-M phase against breast cancer cells9. On the other hand, pyridine derivatives also have a wide-range of therapeutic applications in the area of drug discovery10. Pyridine analogue FTO-IN-5 (Figure 1) as a selective FTO inhibitor could decrease the viability of acute monocytic leukaemia cells and increase the level of N6-methyladenosine in mRNA11. Pyridine analogue FTO-IN-6 selectively inhibited FTO and formed hydrogen bonds with residues Ser318 and Tyr29512.
3-Pyridinylboronic acid normalizes the effects of 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine exposure in zebrafish embryos
Published in Drug and Chemical Toxicology, 2022
Fümet Duygu Üstündağ, İsmail Ünal, Derya Cansız, Ünsal Veli Üstündağ, Hülya Kara Subaşat, A. Ata Alturfan, Pınar Mega Tiber, Ebru Emekli-Alturfan
Substituted pyridines are important components of many drugs and drug candidates (Kadayat et al.2018). Recently, the use of pyridine boronic acids in terms of hydrogen-bound derivatives has attracted attention because of the production of different supramolecular communities based on crystal engineering principles in supramolecular chemistry (Kara et al.2006; Yahsi et al.2015). Pyridinylboronic acids are appropriate for use as subclass of heterocyclic boronic acids in combinatorial approaches in product design and discovery (Liu et al.2013; Fontaine et al.2015). Pyridinium orientation has been shown to determine the mitochondrial uncoupling of the mitochondria-targeted, broad-spectrum anticancer agent F16 (Xu et al. 2018). On the other hand, mitochondrial uncoupling has been also suggested to affect neurons by modulating multiple neuroprotective pathways (Geisler et al. 2017). Although the beneficial effects of boron in the neural activity of the brain have been shown before, the effect of 3-pyridinylboronic acid has not been evaluated so far in PD. Accordingly, the aim of this study was to investigate the effects of 3-pyridinylboronic acid on MPTP exposed zebrafish embryos focusing on the molecular pathways related to neurodegeneration and apoptosis.