cis-trans isomerism

(redirected from Cis-isomer)

cis-trans isomerism

[′si¦stranz ī′säm·ə‚riz·əm]
(organic chemistry)
A type of geometrical isomerism found in alkenic systems in which it is possible for each of the doubly bonded carbons to carry two different atoms or groups; two similar atoms or groups may be on the same side (cis) or on opposite sides (trans) of a plane bisecting the alkenic carbons and perpendicular to the plane of the alkenic system.
References in periodicals archive ?
2]ArX complex, is usually accepted as the dominant reaction pathway [4,23-25], but at the same time a similar reaction can take place with the corresponding cis-isomer, which is especially important for chelating ligands, where the formation of trans-[PdL.
Fermented to the same high quality as that available from Japan, the product is a "natural," all-trans CoQ10 with no cis-isomer impurities.
The acute toxicity of the cis-isomer in the rat LD50 160-300 mg/kg body weight is much higher than that of the trans-isomer LD50 > 2000 mg/kg.
As shown in Table 1, the proportion of cis-isomer decreases as the size and bulk of the alcohol solvent increases.
Cidoxepin is the cis-isomer of the widely prescribed tricyclic compound doxepin.
The activity of the cis-isomer is 7 times weaker, probably because of its nonplanar conformation.
Cis-oak lactone and trans-oak lactone: The cis-isomer is more powerfully aromatic than the trans-isomer.
softening of cell walls, associated with lycopene's bio-accessibility by production of lycopene in tomato tissues more manageable, and by altering some of the trans-isomers of lycopene to cis-isomers may be necessary.
Total [beta]-carotene concentration and the concentration of some [beta]-carotene cis-isomers were measured spectrophotometrically and by high-performance liquid chromatography, respectively.
Similar to the notched IZOD impact strength, there is a gradual increasing trend in the tensile strength with increasing the content of cis-isomers of rubber type.
Concerning the stereoselectivity of glucuronidation, cis-isomers were glucuronidated faster than trans-isomers (15).
As in the case of cis-stilbene and cis-stilbene oxide, the activities of the cis-isomers were much lower than those of the trans-compounds (Sugihara et al.