Chemical Compounds as Trigger Factors of Immediate Contact Skin Reactions
Ana M. Giménez-Arnau, Howard I. Maibach in Contact Urticaria Syndrome, 2014
Safford et al. conducted a study on 20 patients positive to the FMI in 48 hours and classified the FMI ingredients according to the decreasing ability to induce CoU as follows: cinnamic aldehyde, cinnamic alcohol, isoeugenol, hydroxycitronellal, and geraniol.[17] Cinnamic aldehyde and cinnamic alcohol were the strongest urticaria inducers for nonallergic patients. CoU from cinnamic aldehyde has been reported by several authors,[4] leading even to anaphylaxis.[18] Among the many components of Balsam of Peru, cinnamic aldehyde is described as the strongest agent inducing NICoU, followed by cinnamic acid, benzoic acid, and benzaldehyde.[19] Cinnamic aldehyde is the main component of cassia oil (approximately 90%) and cinnamon bark oil (approximately 75%). It is also the main component of artificial cinnamon oil. Smaller quantities are found in many other essential oils. In nature, the trans-isomer is predominant. It is a yellowish liquid with a characteristic spicy odor, strongly reminiscent of cinnamon. Being an unsaturated aldehyde, it undergoes many reactions including hydrogenation to cinnamic alcohol. Its oxidation occurs readily on exposure to air, yielding cinnamic acid. Cinnamic acid has been also used in perfumery, as a flavoring ingredient in pharmaceutical preparations, and in food products. Forsbeck and Skog found CoU from cinnamic acid 5% in petrolatum in three of five patients with immediate skin reactions to Balsam of Peru.[19]
Biological Activities and Safety Aspects of Fucoxanthin
Gokare A. Ravishankar, Ranga Rao Ambati in Handbook of Algal Technologies and Phytochemicals, 2019
FX’s systemic name is 3S,5R,6S,3’S,5’R,6’R)-5,6-Epoxy-3’-ethanoyloxy-3,5’- dihydroxy-6’,7’-didehydro-5,6,7,8,5’,6’-hexahydro-beta,-beta-caroten-8-one. The structure of FX (Figure 22.1) was first elucidated by Englert et al. (1990). FX contains a unique structure with an allelic bond and 5.6- monoepoxy group and six oxygen atoms (Chemspider 2015), with the molecular formula C42H58O6. The unique functional groups hydroxyl, epoxy, acetate and allenic differentiate FX from other carotenoids like β-carotene and astaxanthin. FX extractable solvents are dimethyl sulfoxide (DMSO), ethanol, methanol, dimethyl ether, diethyl ether, petroleum ether, acetone, ethyl acetate and n‐hexane (Kim 2011a; Kanda et al. 2014). FX captures a broader spectrum of light than chlorophyll A and C, (449–540nm), which increases the efficiency of photosynthesis (Pyszniak and Gibbs 1992; Kim 2011b). In nature, FX exists in trans or cis configuration. The trans isomer of FX is the more common, comprising ~90% of that found in nature. The trans isomer is chemically more stable and acts as an active antioxidant cis isomer (Nakazawa et al. 2009; Holdt and Kraan 2011). Molecular structure of FX.
Chemopreventive Agents
David E. Thurston, Ilona Pysz in Chemistry and Pharmacology of Anticancer Drugs, 2021
Due to lycopene’s molecular size, and carbon and hydrogen content, it is highly nonpolar and virtually insoluble in water but will dissolve in organic solvents and oils which explains why lycopene-containing food products will stain most plastics. Also, due to the constraints of the eleven conjugated double bonds, lycopene molecules are long and straight. Each conjugated double bond reduces the energy required for electrons to transition to higher energy states, thus allowing the molecule to absorb visible light of longer wavelengths. As it contains eleven conjugated double bonds, lycopene absorbs all but the longest wavelengths of visible light, causing it to appear deep red. These conjugated double bonds also provide the molecule’s antioxidant activity. While plants and photosynthetic bacteria naturally produce all-trans lycopene, a total of 72 geometric isomers of the molecule are sterically possible. When exposed to heat or light, the molecule can undergo isomerization to any number of these cis isomers, which have a bent shape compared to the linear form of the all-trans isomer. Theoretical studies have suggested different stabilities for the various isomers, with the all-trans and 5-cis isomers having the greatest predicted stability.
The estrogenic activity of resveratrol: a comprehensive review of in vitro and in vivo evidence and the potential for endocrine disruption
Published in Critical Reviews in Toxicology, 2020
Resveratrol (3,5,4′-trihydroxystilbene, MW 228.24 g/mol, Figure 1) is a natural polyphenolic stilbene and common constituent of several edible plants. Two geometric isomers have been purified for resveratrol, the most abundant sterically stable trans-isomer and the cis-isomer. Naturally, both isomers undergo glucosylation to form the glucoside derivatives trans-piceid and cis-piceid, respectively (Romero-Pérez et al. 1999). They also undergo polymerization at low concentrations to form natural oligostilbenes known as viniferins (Korhammer et al. 1995). The biosynthesis of resveratrol and its derivatives is particularly increased following specific physiological and pathological stresses. In addition, regional and cultivar variations influence the levels of resveratrol and its glucosylated and oligomeric products. The level of resveratrol in a variety of food and beverage products has been reported by several studies and ranges from a fraction of a microgram to less than 2 milligrams per product gram or liter (Langcake and Pryce 1976; Siemann and Creasy 1992; Burns et al. 2002; Weiskirchen and Weiskirchen 2016). Generally, the biological actions and therapeutic properties of the trans-isomer dominated most of the scientific literature and are the present focus of this review. However, it is noteworthy that there has been a simultaneous interest in the actions of the cis-isomer- albeit to a lower extent, and a rising interest in the actions of the glucoside and oligomeric derivatives and most recently, the biological metabolites of the trans-isomer.
PROTACs for BRDs proteins in cancer therapy: a review
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Chao Wang, Yujing Zhang, Shanbo Yang, Wujun Chen, Dongming Xing
Although PROTAC 20 is a highly active BET degrader that has been shown to achieve complete regression of prostate cancer in a CRPC mouse xenograft model, it also has general cytotoxic effects. To address the cytotoxic effects of PROTAC 20, Pfaff et al. designed photoswitchable PROTAC (PROTAC 22, Figure 10) by including ortho-F4-azobenzene linkers between JQ-1 and VHL ligand56. This highly bistable but photoconvertible structural component led to a reversible control of the topological distance between the two ligands. The observed azo-cisisomer was inactive because the distance defined by the linker was too short to allow the formation of a complex between the protein binding partners. In contrast, the azo-trans-isomer was active because it allowed the engagement of both protein partners to form the necessary and productive ternary complex. Importantly, due to the bistable nature of the ortho-F4-azobenzene employed, the photostability of PROTAC 22 was durable and did not require continuous irradiation. This technique provided a reversible switch for protein degradation compatible with the intracellular environment and, therefore, might be useful in the experimental exploration of biological signalling pathways, such as those critical for oncogenic signal transduction. By enabling reversible activation and deactivation of protein degradation, PROTAC 22 provided an advantage over conventional photocaging strategies that irreversibly release active agents.
Pharmacokinetics and brain targeting of trans-resveratrol loaded mixed micelles in rats following intravenous administration
Published in Pharmaceutical Development and Technology, 2020
Roshan Katekar, Ganeshkumar Thombre, Mohammed Riyazuddin, Athar Husain, Hiral Rani, Kusuma Sushma Praveena, Jiaur R. Gayen
Resveratrol (RES) is a phytoalexin (compound released by a plant in response to pathogenic infection) and oxidative polyphenolic compound naturally sourced in grapes, berries, peanuts, red wine (Pangeni et al. 2014). Geometric isomers of naturally occurring RES are Cis and Trans configurations, yet the major and mostly studied configuration that is Trans isomer has undertaken for study. Trans-RES (T-RES) is highly photosensitive and tends to convert into Cis-form (Neves et al. 2016) which is not as much potent as T-RES rather than its antiplatelet action (Bertelli et al. 1996).
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