142506-26-1Relevant articles and documents
Optimisation of extraction procedure and development of LC–DAD–MS methodology for anthocyanin analysis in anthocyanin-pigmented corn kernels
Hong, H. T.,Netzel, M. E.,O'Hare, T. J.
, (2020)
An ultra-high-performance liquid chromatography–diode array detector–mass spectrometry method was developed for characterisation and quantification of anthocyanin components in complex corn-kernel matrices. The anthocyanin profiles and total anthocyanin content (TAC) of mature seeds of five types of anthocyanin-pigmented corn were reported. Internal standard was used to validate the efficiency of extraction and optimise the liquid extraction procedure for anthocyanins. A total of eighteen anthocyanins were identified and quantified. Cyanidin-based glucosides were the major pigments of purple-pericarp sweetcorn (75.5% of TAC) and blue-aleurone maize (91.6%), while pelargonidin-based glucosides composed the main anthocyanins of reddish-purple-pericarp sweetcorn (61.1%) and cherry-aleurone maize (74.6%). Importantly, previous studies reported the presence of acetylated and succinylated anthocyanins in corn kernels; these compounds were found to be artefact pigments, generated during the extraction process. These crucial findings provide the correct anthocyanin profiles of pigmented corns, and emphasise the importance of using acidified solutions for the extraction of corn-based anthocyanins.
New acylated cyanidin glycosides extracted from underutilized potential sources: Enzymatic synthesis, antioxidant activity and thermostability
Fernandez-Aulis, Fernanda,Torres, Andrea,Sanchez-Mendoza, Ernesto,Cruz, Luis,Navarro-Ocana, Arturo
, (2020)
Interest in anthocyanins has increased remarkably in recent decades, although their wider application has been hampered by instability problems. Thus, this study aimed at developing a strategy to gain access to more stable anthocyanins via enzymatic esterification. For that purpose, three cyanidin derivatives were obtained from underutilized, but easily accessible sources, and their total anthocyanin content was quantified. The purity of cyanidins obtained ranged from 40% to 88% depending on their source. Subsequently, the critical enzymatic reaction conditions were established, and the best results were found using tert-butanol as a solvent, 20 g/L of lipase B from Candida Antarctica, and vinyl cinnamate as acyl donor at ratio 250:1 (acyl donor to anthocyanin). Finally, five new acylated anthocyanin derivatives were synthesized with improved antioxidant activity and thermostability, in comparison to the cyanidin-3-glucoside, which is an advantageous feature for industrial applications.
Functional characterization of a UDP-glucose:flavonoid 3-O- glucosyltransferase from the seed coat of black soybean (Glycine max (L.) Merr.)
Kovinich, Nik,Saleem, Ammar,Arnason, John T.,Miki, Brian
experimental part, p. 1253 - 1263 (2011/04/22)
The seed coats of black soybean (Glycine max (L.) Merr.) accumulate red (cyanidin-), blue (delphinidin-), purple (petunidin-), and orange (pelargonidin-based) anthocyanins almost exclusively as 3-O-glucosides; however, the responsible enzyme has not been identified. In this study, the full-length cDNA which encodes the enzyme that catalyzes the final step in anthocyanin biosynthesis, namely UDP-glucose:flavonoid 3-O-glucosyltransferase (UGT78K1), was isolated from the seed coat tissue of black soybean using rapid amplification of cDNA ends (RACE). Of the 28 flavonoid substrates tested, the purified recombinant protein glucosylated only anthocyanidins and flavonols, and demonstrated strict 3-OH regiospecificity. Galactose could also be transferred with relatively low activity to the 3-position of cyanidin or delphinidin in vitro. These findings are consistent with previous reports of mainly 3-O-glucosylated and minor amounts of 3-O-galactosylated anthocyanins in the seed coat of black soybean. The recombinant enzyme exhibited pronounced substrate inhibition by cyanidin at 100 μM acceptor concentration. Transfer of UGT78K1 into the Arabidopsis T-DNA mutant (ugt78d2) deficient in anthocyanidin and flavonol 3-O-glucosyltransferase activity, restored the accumulation of anthocyanins and flavonols, suggesting the in vivo function of the enzyme as a flavonoid 3-O-glucosyltransferase. Genomic and phylogenetic analyses suggest the existence of three additional soybean sequences with high similarity to UGT78K1. RT-PCR confirmed the co-expression of one of these genes (Glyma08g07130) with UGT78K1 in the seed coat of black soybean, suggesting possible functional redundancies in anthocyanin biosynthesis in this tissue.
