Isolation and identification of .beta.-citraurol, a C30 carotenoid in citrus

Abstract

ators on the market, coupled with the expanding investigation of 0 3 water purification, has made ozonation available to most laboratories. (14) See, for example, E. P. Parry and D. H. Hern. Environ. Sci. Techno/., 7, (15) Ir spectra of the VPC collected ketones agreed closely with those from the literature. Sources: C.

LC–MS-Based Profiling Provides New Insights into Apocarotenoid Biosynthesis and Modifications in Citrus Fruits

“…This biosynthetic route is more likely than the previously supposed one, postulating a new biosynthesis pathway for C 30 compounds (β-citraurin, β-citraurinene, and β-citraurol) different than that of the C 40 carotenoids. 47,48 This scenario resembled the formation of β-apo-10′-carotenol by an endogenous aldehyde dehydrogenase from aldehyde β-apo-10′-carotenal upon the expression of the potato StCCD4 in βcarotene-accumulating E. coli cells. 50 These results indicate that the conversion of apocarotenoid aldehydes into corresponding alcohols is conserved in E. coli and plants.…”

“…Considering the authentic enzymatic role of CitCCD4b in cleaving zeaxanthin or β-cryptoxanthin to produce β-citraurin in vitro, it can be assumed that alcohol β-citraurol originates through the cleavage of a C 40 carotenoid, which leads to the aldehyde β-citraurin that is converted by an endogenous citrus aldehyde dehydrogenase into the corresponding alcohol. This biosynthetic route is more likely than the previously supposed one, postulating a new biosynthesis pathway for C 30 compounds (β-citraurin, β-citraurinene, and β-citraurol) different than that of the C 40 carotenoids. , This scenario resembled the formation of β-apo-10′-carotenol by an endogenous aldehyde dehydrogenase from aldehyde β-apo-10′-carotenal upon the expression of the potato StCCD4 in β-carotene-accumulating E. coli cells .…”

“…36,47,48 The accurate mass of the protonated precursor ion from a peak at a retention time of 9.25 min was m/z 435.32523 ([M + H] + ), the MS/MS spectrum of this peak displayed the fragment ion at m/z 417.31485 [M + H − H 2 O] + , corresponding to the loss of one molecule of water, and the UV absorption maxima of this peak were 425 and 450 nm (Figure 5A,B). These features are consistent with previous literature data on β-citraurol (Leuenberger et al 47 ). We detected β-citraurol in the CitCCD4b-overexpressing 4BCR and 4BHCR lines but not in the HCR and CR lines (Figure 5C).…”

“…The occurrence of specific C 30 apocarotenoid pigments, including β-apo-8′-carotenal, β-citraurin, β-citraurinene, and β-citraurol, is characteristic for the pigment composition in red peels of some oranges, mandarins, or their hybrids. ,,, These C 30 apocarotenoids are rarely found in other plants, thus representing an almost unique feature of the genus Citrus . β-citraurin, β-citraurinene, and β-citraurol contain the same β-ionone ring with a hydroxyl group at the C 3 position but differ in the functional group at the linear end of the molecule (see structures in Figure ).…”

“…β-citraurin, β-citraurinene, and β-citraurol contain the same β-ionone ring with a hydroxyl group at the C 3 position but differ in the functional group at the linear end of the molecule (see structures in Figure ). These three apocarotenoids can be distinguished in UHPLC–MS/MS analysis based on the retention time, accurate m / z mass, MS/MS spectra, and UV/vis spectra (Figure A,B). ,, The accurate mass of the protonated precursor ion from a peak at a retention time of 9.25 min was m / z 435.32523 ([M + H] + ), the MS/MS spectrum of this peak displayed the fragment ion at m / z 417.31485 [M + H – H 2 O] + , corresponding to the loss of one molecule of water, and the UV absorption maxima of this peak were 425 and 450 nm (Figure A,B). These features are consistent with previous literature data on β-citraurol (Leuenberger et al).…”