Geometric specificity of alcohol dehydrogenases and its potential for separation of trans and cis isomers of unsaturated aldehydes.

Abstract

The geometric specificity of three different alcohol dehydrogenases (alcohol:NAD+ oxidoreductase, EC 1.1.1.1) (from yeast, from horse liver, and from Leuconostoc mesenteroiles) in the reduction oftrans-and cis-cinnamaldehydes has been investigated. All three enzymes display a remarkable trans specificity: they react with the trans isomer 7 to 647 times faster than with its cis counterpart. Experiments with the enzymatic reduction of 3-phenylpropionaldehyde, a saturated analog of cinnamaldehyde, have revealed that whereas tranm-cinnamaldehyde possesses the "right" configuration for the active centers ofthe alcohol dehydrogenases, the cis isomer apparently does not fit the active centers well. All three alcohol dehydrogenases studied also exhibit a marked trans specificity in the reaction with a-methylcinnamaldehyde. The geometric specificity of alcohol dehydrogenases can be used for the production of otherwise hard to synthesize cis isomers of unsaturated aldehydes from their readily available trans counterparts: trans-cinnamaldehyde was irradiated with ultraviolet light (which converted it to a mixture of trans and cis isomers) then treated with NADH and yeast alcohol dehydrogenase (which selectively reduces only trans aldehyde into the alcohol), and finally the mixture of cis-cinnamaldehyde and trans-cinnamyl alcohol was separated easily by preparative column chromatography.The separation of trans and cis isomers of unsaturated compounds is a classical problem in organic chemistry (1). In addition to its fundamental interest, this problem is also of great practical significance. Most functional properties of organic molecules are determined by their molecular geometry, and therefore these properties for trans and cis isomers are bound to be different. This can be illustrated by the following examples. Only cis isomers of substituted cinnamic acids possess plant-growth regulatory activity (2). Only trans diethylstilbestrol displays estrogenic activity (3). Balsamo et aL (4) have demonstrated that whereas trans isomers of N-alkyl-a,4-dimethylcinnamamides exhibit central nervous system-depressant activity, the corresponding cis isomers display central nervous systemstimulant activity. Particularly striking examples of dramatic differences in biological activity of trans and cis isomers can be found in the area of sex pheromones. These pheromones typically are long-chain unsaturated aldehydes, alcohols, or esters. In many cases one geometric isomer of a given pheromone is a sex attractant for one insect species, whereas its counterpart attracts another species (5).In order to take advantage of the difference in properties of the geometric isomers of unsaturated compounds, one should be able to readily prepare the trans and cis isomers separately. Unfortunately, most conventional chemical syntheses ofa given unsaturated compound usually yield just, one particular isomer, either trans or cis (6).The isomer produced can, however, be converted into a mixture of trans and cis isomers by irradiation with ultravi...

Insecticidal effects of substances from cinnamon bark – eugenol, trans-cinnamaldehyde and cinnamaldehyde to yellow mealworm

“…Our observations are in tune with this statement. The higher activity of trans-cinnamaldehyde than cinnamaldehyde, shown in our research, is in tune with the remark of Klibanov and Giannousis (1982) who claim higher activity of transisomer of cinnmaldehyde is more active than the cis-one. Cinnamaldehyde is a mixture of both isomers and therefore, its activity was lower than the pure trans-cinnamaldehyde.…”

“…Cinnamon oil is comprised mainly of cinnamaldehyde (the chief chemical component, forming up to 90% of cinnamon oil) and eugenol (Dayananda et al 2004). Cinnamaldehyde comprises of two isomers: cis and trans, the latter being the predominant one and signi cantly more reactive in biological systems than the cis-isomer (Klibanov and Giannousis 1982;Baker and Grant, 2018). The so far documented prohealth effects of these compounds are used primarily in medicine and dentistry due to their bactericidal, fungicidal, anti-in ammatory, and anti-proliferative properties (Jham et al 2005 Usai and De Sotto, 2023).…”

Cinnamaldehyde inhibits psoriasis‑like inflammation by suppressing proliferation and inflammatory response of keratinocytes via inhibition of NF‑κB and JNK signaling pathways

“…Cinnamaldehyde (CIN) is a Traditional Chinese medicine that is derived from the dried bark of the Cinnamomum lauraceae ( Cinnamomum cassia Presl) plant ( 13 ). CIN was previously reported to exert potent fungicidal, antitumor, immunological and anti-inflammatory activities ( 14 ). In addition, CIN has been found to downregulate the expression levels of the proinflammatory cytokines, TNF-α, IL-1β and IL-6, in lipopolysaccharide (LPS)-stimulated macrophages ( 15 ).…”