Emollient Esters and Oils
Randy Schueller, Perry Romanowski in Conditioning Agents for Hair and Skin, 2020
Hydrolytic stability is a major consideration for all esters. Possibly one of the reasons for the popularity of the isopropyl alcohol esters of fatty acids in preference to similar esters that can be made from a low-molecular-weight acid (such as propionic acid) and a fatty alcohol, is their improved hydrolytic stability. It is important to consider that when an ester such as isopropyl myristate does hydrolyze, the resulting products are isopropyl alcohol and myristic acid. However, when an ester such as myristyl propionate hydrolyzes, the resulting components are myristyl alcohol and propionic acid. In this example, isopropyl alcohol would have a much more agreeable odor than propionic acid. Additionally, the propionic acid will lower the product pH possibly to a point where it will be detrimental to the product or consumer.
Effects of Essential Oils on Human Cognition
K. Hüsnü Can Başer, Gerhard Buchbauer in Handbook of Essential Oils, 2020
Evidence for the influence of physicochemical odorant properties on visual information processing was supplied by Michael and colleagues (Michael et al. 2005). These authors found that the exposure to both allyl isothiocyanate (AIC), a mixed olfactory/trigeminal stimulus, and 2-phenyl ethyl alcohol (2-PEA), a pure olfactory stimulant, impaired performance in a highly demanding visual attention task. The task involved reaction to a target as well as neglecting a distractor that appeared at different time intervals. In trials without a distractor, only 2-PEA significantly increased the reaction times of healthy subjects; in trials with a distractor, subjects reacted more slowly in both odor conditions as compared to the no-odor control condition. However, AIC impaired performance independent of the interval between distractor and target, whereas 2-PEA only had a negative effect when the interval between target and distractor was short. While 2-PEA seemed to have led to performance decrements by decreasing subjects’ arousal levels, AIC as a strong trigeminal irritant seemed to have shifted attention toward the distractor stimuli. A similar observation has also been made for the annoying odor propionic acid (Hey et al. 2009). In this study, the error rate in a response-inhibition task increased as a function of odorant concentration, suggesting a relationship between cognitive distraction and sensory annoyance.
Methylmalonic acidemia
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop in Atlas of Inherited Metabolic Diseases, 2020
Propionic acid is synthesized by intestinal bacteria, and this may be an important source of propionate and methylmalonate in these patients [110]. Treatment with neomycin or metronidazole may reduce levels of propionic and MMAs in body fluids [108–110]. Doses of metronidazole have ranged from 10 to 20 mg/kg per day and have been divided into three doses. Neomycin has been used in a dose of 50 mg/kg. Other antibiotics, such as bacitracin, paromycin, clindamycin, or vancomycin, may be useful in acute situations. Lincomycin was not effective [110]. In our experience, intermittent antibacterial therapy has been useful, suggesting that clonal populations of propionate-forming bacteria may be intermittently present in some patients. An effect of antibiotic treatment on metabolite accumulation may be especially useful during a crisis of metabolic decompensation. A sudden increase in MMA excretion unaccompanied by dietary change or stimulus for catabolism may suggest a bacterial source and an argument for neomycin or metronidazole.
Anti-influenza A virus activity and structure–activity relationship of a series of nitrobenzoxadiazole derivatives
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Francesco Fiorentino, Marta De Angelis, Martina Menna, Annarita Rovere, Anna Maria Caccuri, Francesca D’Acunzo, Anna Teresa Palamara, Lucia Nencioni, Dante Rotili, Antonello Mai
Overall, 10 compounds of the library possessed antiviral activity, all of them being 4-thioether derivatives of NBD. The active molecules can be divided into three subgroups: (i) the emisuccinic esters 9, 10, 11; (ii) the propionic acid derivatives 12, 17, and 19; (iii) the 4-benzylthio derivatives 25, 41, 42. In group (i), it is apparent that increasing the length of the alkyl chain reduces the antiviral activity as demonstrated by the increased IC50 value of 10 compared to 9. In addition, the introduction of polar atoms, such as oxygen, is detrimental for compound activity as indicated by the higher IC50 value of 11 compared to 9. In group (ii), methylation of the carboxylic acid function of N-α protected cysteine residues decreases the IC50 value at least six-fold (compare 17 with 19), and the subsequent removal of the protected amino group at α position leads to a further increase of antiviral potency (compare 12 with 17) suggesting that a small methyl propionate side chain is important for compound activity. In group (iii), the introduction of both carboxy (41) and carbethoxy (42) groups determine a decrease in antiviral activity compared to 25, indicating that substitutions with polar moieties at para position are unfavourable for the 4-benzylthio-NBD derivatives series. Overall, the present data suggest that compact, hydrophobic substitutions are favourable for antiviral activity, alternatively benzyl derivatives are promising anti-IV compounds, although different substitutions in the benzene ring need to be explored.
Gut microbes from the phylogenetically diverse genus Eubacterium and their various contributions to gut health
Published in Gut Microbes, 2020
Arghya Mukherjee, Cathy Lordan, R. Paul Ross, Paul D. Cotter
The genus Eubacterium consists of Gram positive, uniform or pleomorphic non-spore forming, obligately anaerobic, and chemoorganotrophic bacterial rods. Species in this genus can be saccharoclastic or nonsaccharoclastic and motile or immotile in nature.19 Bacteria from this genus produce mixtures of organic acids from carbohydrates or peptone, which may include copious amounts of butyric, acetic and formic acids but do not produce: (a) only lactic acid, (b) propionic acid as the major acid, (c) greater quantities of acetic acid than lactic acid with or without the formation of formic acid and (d) lactic and succinic acid with small quantities of acetic or formic acid.5 This definition is rather loose and leads to the incorporation of species in the genus by default; historically resulting in the inclusion of species with a variety of phenotypes and genotypes in the genus and, ultimately, making it highly heterogeneous. According to the latest iteration of the Bergey’s Manual of Systematics of Bacteria and Archaea19 as well as NCBI Taxonomy, the genus Eubacterium belongs to the bacterial phylum Firmicutes, order Clostridiales and family Eubacteriaceae. However, according to the Genome Taxonomy Database (GTDB), which uses whole/draft genome information for classification of taxa, the genus should be assigned to the family Lachnospiraceae.20 The genus currently consists of 42–44 species depending on the taxonomy being followed, and the major species of interest in relation to the human gut include Eubacterium rectale, E. hallii, E. ventriosum, E. eligens, E. coprostanoligens, and E. limosum. The DNA G + C content (mol%) of the genus varies from 30 to 57% and the type strain is Eubacterium limosum.
The potential role of gut microbiota and its modulators in the management of propionic and methylmalonic acidemia
Published in Expert Opinion on Orphan Drugs, 2018
Alberto Burlina, Sebastian Tims, Francjan van Spronsen, Wolfgang Sperl, Alessandro P. Burlina, Mirjam Kuhn, Jan Knol, Maryam Rakhshandehroo, Turgay Coşkun, Rani H Singh, Anita MacDonald
An in vitro study showed galacto-oligosaccharides (GOS) positively affected microbiota composition, significantly increasing acetate compared with propionate and butyrate [73]. Furthermore, an in vivo model in rats showed ingestion of GOS with a probiotic also increased butyrate formation in the gut [74]. Overall, data supporting a role for prebiotics to reduce propionic acid remain limited and there are no published studies of prebiotics in patients with PA/MMA.
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