Neo-Tran

One of the best illustrations of high specificity is di(4-chlorophenoxy) methane (Neo-tran), which has been used for some time commercially in the field, principally for the control of the citrus red mite. So far there has been no indication of undesirable effect upon pollinating insects or on desirable predators or parasites. 

Figure 6-17 Absorption Spectra of the Three Stereoisomers of Beta Carotene. B - neo-p-carotene U = neo-p-carotene-U T = all-trans-p-carotene. a, b, c, and d indicate the location of the mercury arc lines 334.1, 404.7, 435.8 and 491.6 nm, respectively. Source From F. Stitt et al Spectrophotometric Determination of Beta Carotene Stereoisomers in Alfalfa, J. Assoc. Off. Agric. Chem. Vol. 34, pp. 460-471, 1951.

The structural formula of Figure 9-1 shows the unsaturated character of vitamin A. The all-rrans form is the most active biologically. The 13-cis isomer is known as neovitamin A its biological activity is only about 75 percent of that of the all-trans form. The amount of neo-vitamin A in natural vitamin A preparations is about one-third of the... 

Proprietary Names. Alupram Apozepam Atensine Dialar Diazemuls D-Tran Ducene E-Pam Evacalm Lorinon Meval Neo-Calme Novodipam Paxel Pro-Pam Serenack Solis Stesolid Stress-Pam Tensium Valium Valrelease Vivol. 

IDROSSIZINA NEO-CALMA NEUROZINA D NP 212 PAMAZONE PARENTERAL PAXISTIL PLACIDOL PLAXIDOL TRAN-Q TRAQUIZINE UCB 492 U.CB 4492 VESPARAZ-WIRKSTOFF... 

Both naturally occurring enantiomers of carvone were selectively reduced by B. sulfurescens (Scheme 71). (-)-Carvone was reduced to (-h)-dihydrocarvone (trans) and further to (-H)-neodihydrocarveol, whereas (-i-)-carvone was reduced to (-)-isodihydrocarvone (cis), which was then converted to (-)-neo-isodihydrocarveol. Similar reductions with identical stereoselectivities were observed earlier with Pseudomonas ovalis (strain 6-1) and with a strain of Aspergillus niger. ... 

The two limonene epoxides (93) behave differently when treated with lithium in ethylamine. The trans-epoxide (93a) yields exclusively trons-) -terpineol (94a), excess lithium and long reaction periods reducing the double bond, whereas the c/s-epoxide (93b) yields not only cis-)8-terpineol (94b), but also neo- (95) and isodihydrocarveol (96). The menth-l-ene epoxides [e.g. (97)] behave similarly. ... 

An enzyme in the retina specially and rapidly (especially in dim light) catalyzes the conversion of all trans retinene to 11-cis retinene (neo-b retinine), by the enzyme retinene isomerase. 

While only two geometrical isomers exist in simple unsaturated molecules, a number of cis-trans isomers can exist in polyenes (e.g. carotenoids ). Normally, the alI-/ra/w-isomer is preponderant in carotenoids. Isomerization of the all-ftms-carotenoids by acid- or iodine-catalysis yield the so-called neo-carotenoids. The neo-carotenoids are believed to possess one c/s-ethylenic bond in the central position of the conjugated chain9. The neo-carotenoids exhibit not only a weaker long wavelength band 470 nyx) than the all... 

Figure 7.3. Absorption spectra of all-trans (1). poly-cli (2) and neo (3) lycopenes ...

The stem name carotene brings with it an implication of trans double bond geometry for all bonds. Note that this is opposite to that of polyene FA discussed earlier (see Section 3.2.4). If a cis double bond is present, this is distinguished in the structural name as either cis-" or Z- following the appropriate carbon location. Compounds known to contain a cis double bond but where the location is unknown, or isomers of carotenes with an unlocated cis double bond, are given the prefix neo- and an alphabetical suffix. 

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