Hydrophilic carotenoids: facile syntheses of carotenoid oxime hydrochlorides as long-chain, highly unsaturated cationic (bola)amphiphiles

Aggregation of Fucoxanthin and Its Effects on Binding and Delivery Properties of Whey Proteins

“…As shown in Figure C, the CAR of water/ethanol was reduced as the rate of water addition slowed, indicating that the J-aggregates became easier to produce. A previous study reported that the H-aggregates of astaxanthin oximium hydrochloride were formed when water was continuously added to its methanol solution in small increments, whereas the J-aggregates were produced when it was immediately dispersed in water . It seemed that was contrary to the result of this study, which might be due to the positively charged terminal rings of the astaxanthin oximium hydrochloride.…”

“…A previous study reported that the H-aggregates of astaxanthin oximium hydrochloride were formed when water was continuously added to its methanol solution in small increments, whereas the J-aggregates were produced when it was immediately dispersed in water. 40 It seemed that was contrary to the result of this study, which might be due to the positively charged terminal rings of the astaxanthin oximium hydrochloride. In their case, when the aggregates were selfassembled in a card-pack form, the electrostatic repulsion between the molecules was greater than the head-to-tail arrangement.…”

Hydrophilic Carotenoids: Recent Progress

“…Sliwka et al also synthetized and studied thoroughly remarkable phospholipid derivatized carotenoids like 4 [14,15,16], and also investigated the physicochemical properties of natural hydrophilic carotenoids such as bixin and crocin [17,18,19]. Recently, they have synthetized aldoxime and ketoxime hydrochlorides from oxo carotenoids, which showed moderate water dispersibility [20]. The antioxidant and aggregation properties of all these compounds were extensively studied in the above mentioned articles [21].…”

Key to Xenobiotic Carotenoids

“…Various carotenoid derivatives prepared for analytical purposes (oximes, hydrazones amides etc. ) are not mentioned [34,35], unless the derivative has also found an application extending characterization, e.g., canthaxanthin oxime was skipped, canthaxanthin oxime hydrochloride 21N as a surface active hydrophilic carotenoid was included [22]. Some carotenoids are drawn in the concise all- trans form, since the dimension of the actual cis -isomers would be too space demanding, e.g., 32N and 33N .…”

“…Carotenoid thione 2S , synthesized previously from a commercial carotenoid in a one-step synthesis, could probably have been more appropriate for the investigation [20]. Even an author sensitized to xenobiotic carotenoids witnessed ignorance; compounds 25N , 27N , 29N were not cited in a paper on carotenoid oxime hydrochlorides 19N-22N [21,22]. Unfamiliarity with heterocarotenoids is possibly the cause for further lack of mention, e.g., nitrile carotenoid 6N was patented in 1990 and published in 2011 without referring to previous work from 1988; thienyl carotenoid 3◉S , first reported in 1981, was not cited when the compound was resynthesized 20 years later (for an explanation of the designation 3 S see Section 4: Nomenclature).…”