(4S)-2,6,6-trimethyl-4-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-cyclohexene-1-carbaldehyde(Picrocrocin,C16H26O7) is a monoterpene glycoside precursor of safranal. Picrocrocin is a beta-D-glucoside of beta-cyclocitral; the precursor of safranal. Picrocrocin is the compound most responsible for the bitter taste of saffron. Picrocrocin derives from a beta-cyclocitral. It is found in the spice saffron, which comes from the crocus flower[1]. Picrocrocin has a bitter taste, and is the chemical most responsible for the taste of saffron.

Picrocrocin is considered to be the main bitter principle of saffron. It is a monoterpene glycoside precursor of safranal (C10H14O), the major volatile oil responsible for the aroma. β-Glucosidase action on picrocrocin liberates the aglycone, 4-hydroxy-2,6,6-trimethyl-1-cyclohexene-1-carboxaldehyde (HTCC, C10H16O2)) which is transformed to safranal by dehydration during the drying process of the plant material.

During the drying process, picrocrocin liberates the aglycone (HTCC, C10H16O2) due to the action of the enzyme glucosidase. The aglycone is then transformed to safranal by dehydration. Picrocrocin is a degradation product of the carotenoid zeaxanthin[2].

Picrocrocin is a glucoside of safranal; a bitter-tasting substance. Food colour and flavouring ingredient During the drying process picrocrocin liberates the aglycone due to the action of the enzyme glucosidase. The aglycone is then transformed to safranal by dehydration. Picrocrocin is a degradation product of the carotenoid zeaxanthin; Picrocrocin is a glycoside formed from glucose and safranal. It is found in the spice saffron, which comes from the crocus flower. Picrocrocin has a bitter taste and is the chemical most responsible for the taste of saffron; It is believed that picrocrocin is a degradation product of the carotenoid zeaxanthin (Wikipedia); Picrocrocin is a monoterpene glycoside precursor of safranal. It is found in the spice saffron, which comes from the crocus flower. Picrocrocin has a bitter taste and is the chemical most responsible for the taste of saffron.

Fig 1. Chemical structure formula and three-dimensional structure of (4S)-2,6,6-trimethyl-4-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy-cyclohexene-1-carbaldehyde

Picrocrocin is a monoterpene glycoside precursor of safranal. Picrocrocin is found in the spice saffron, which comes from the crocus flower. Picrocrocin is a degradation product of the carotenoid zeaxanthin. Picrocrocin exhibits growth inhibitory effects against SKMEL-2 human malignant melanoma cells by targeting JAK/ STAT5 signaling pathway, cell cycle arrest and mitochondrial mediated apoptosis[3-5].

References

[1] Caballero-Ortega H, Pereda-Miranda R, Abdullaev FI (2007). "HPLC quantification of major active components from 11 different saffron (Crocus sativus L.) sources". Food Chemistry. 100 (3): 1126–1131. 
[2] Pfander, H.; Schurtenberger, H. (1982). "Biosynthesis of C20-carotenoids in Crocus sativus". Phytochemistry. 21 (5): 1039–1042.
[3]  Diretto G, Ahrazem O, Rubio-Moraga Á, Fiore A, Sevi F, Argandoña J, Gómez-Gómez L. UGT709G1: a novel uridine diphosphate glycosyltransferase involved in the biosynthesis of picrocrocin, the precursor of safranal in saffron (Crocus sativus). New Phytol. 2019 Oct;224(2):725-740.
[4] Cardone L, Castronuovo D, Perniola M, Cicco N, Candido V. Evaluation of corm origin and climatic conditions on saffron (Crocus sativus L.) yield and quality. J Sci Food Agric. 2019 Oct;99(13):5858-5869.
[5] Parizad S, Dizadji A, Habibi MK, Winter S, Kalantari S, Movi S, Lorenzo Tendero C, Alonso GL, Moratalla-Lopez N. The effects of geographical origin and virus infection on the saffron (Crocus sativus L.) quality. Food Chem. 2019 Oct 15;295:387-394.