Crocetin esters

Carmona, M. et al., Crocetin esters, picrocrocin and its related compounds present in Crocus sativus stigmas and Gardenia jasminoides fruits. Tentative identification of seven new compounds by LC-ESl-MS, J. Agric. Food Chem., 54, 973, 2006. 

Crocetin [27876-94-4] Cl Natural Yellow 6 Cl 75100) occurs in saffron as crocin [42553-65-1] (46), the digentiobiose ester of crocetin (47). 

There have been many applications of the Wittig reaction in multistep syntheses. The reaction can be used to prepare extended conjugated systems, such as crocetin dimethyl ester, which has seven conjugated double bonds. In this case, two cycles of Wittig reactions using stabilized ylides provided the seven double bonds. Note the use of a conjugated stabilized ylide in the second step.250... 

The esterification can also be carried out as a one-pot reaction without isolation of the azolide for example, an 80% yield of crocetin bis(/ -D-glucosyl ester) was obtained via the triazolide. 1953 Reactions of 8 -apo-/ -carotene-8 -oic acid with D-galactose or lactose were claimed to proceed also with a high degree of regioselectivity.11963... 

The ratio of the a- to the j -anomeric D-glucosyl ester can be influenced by changing the reaction conditions. In DMF the a-anomer of the crocetin bis(D-glucosyl ester) was formed in about 70% yield.[196] Esterification of D-glucose with the imidazolides of benzoic acid or stearic acid in pyridine furnished a mixture of the a- and j -anomers of the C(l) glucosyl ester.[196]... 

Figure 13.7 Glycosyl esters of trans and cis crocetin (A) (3 D glycosyl (B) f3 D gentiobiosyl (C) three (3 D glycosyl...

Crocus sativus L. Shi Hong Hua (Saffron) (root) Crocetin, crocetin geniobiose glucose ester, crocetin di-glucose ester, crotin, lycopene, beta-carotene.33-450 Ameliorating effect on ethanol-induced impairment of learning and memory. 

Crocetin di-glucose ester Crocetin geniobiose glucose ester... 

An oral administration of crocin had no effect on memory acquisition in normal mice but improved the ethanol-induced impairment of learning behaviors of mice in passive avoidance performance tasks. This phenomenon resembled that of crude extract of saffron as reported previously. The tendencies of the effect between CSE and crocin are similar to each other. From these results it can be easily speculated that crocin is the most important principle in crude extract of saffron. Other crocetin glucoside esters weakly antagonized the blocking effect of ethanol on the LTP compared to crocin. 

Crocetin diethyl ester [5056-14-4] M 384.5, m 218-219°, e1 2340 (400nm), 3820 (422nm), 3850 (450nm) in pet ether. Purified by chromatography on a column of silica gel G. Crystd from benzene. Stored in the dark, under an inert atmosphere, at 0°. 

Fig- (3 ). Seasonal variation of crocetin glucose esters in C. sativus L. 

MeOH gradient solution (1 0 to 0 1) to yield crocetin di-glucose ester (0.41 g), crocetin gentiobiose glucose ester (5.10 g) and crocin (5.69 g). 

Crocin of 50 mg/kg ameliorated the blocking effect of ethanol on the LTP at approximately 84% compared to the control as indicated in Fig. (10). Crocetin gentiobiose glucose ester also antagonized the blocking effect of ethanol on the LTP dose-dependently. But die intensity is not so strong, about a half of crocin when compared the intensity of 50 mg/kg. On the other hand, crocetin di-glucose ester did not remove the inhibitory effect of ethanol on the LTP. 

Saffron extract contains many carotenoids such as crocetin, crocetin di-glucose ester, crocetin gentiobiose glucose ester, and crocin (crocetin di-gentiobiose ester), whose chemical structures are shown in Figure 58.1. These carotenoids scavenge free radicals, especially superoxide anions, and so may protect cells from oxidative stress. Indeed, it has been demonstrated that these carotenoids are useful in sperm cryoconservation and in protecting heptocytes from toxins. 

FIGURE 58.1 Chemical structures of crocetin (A), crocetin diglucose ester (B), crocetin gentiobiose glucose ester (C), and crocin (D). 

Crocetin (C20) is a yellow (IP)2—(PI)2-derived dicarboxylic, acid (generalized structure -OOG-Gig-GOO-) from the styles of Crocus sativus (Iridaceae) (the saffron of Indian cooking and Buddhist robes). Grocin, the digentiobiose ester of crocetin, is water soluble, unlike other carotenoids which are lipophilic (fat soluble). Crocetin is a protein kinase inhibitor. Excess vitamin A (or excess pro-vitamin A) ingestion is toxic (dog liver consumption having caused the death of Sir Douglas Mawson s explorer companions in the Antarctic by this mechanism). 

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