Astaxanthin: structural and functional aspects

Abstract

1 Article based on L.M.J. SEABRA' s thesis project entitled "Litopenaeus vannamei shrimp: components of nutritional importance in meat and processing waste. A B S T R A C TAstaxanthin, a carotenoid belonging to the xanthophyll class, has stirred great interest due to its antioxidant capacity and its possible role in reducing the risk of some diseases. Astaxanthin occurs naturally in microalgae, such as Haematococcus pluvialis and the yeast Phaffia rhodozyma, and has also been considered to be the major carotenoid in salmon and crustaceans. Shrimp processing waste, which is generally discarded, is also an important source of astaxanthin. The antioxidant activity of astaxanthin has been observed to modulate biological functions related to lipid peroxidation, having beneficial effects on chronic diseases such as cardiovascular disease, macular degeneration and cancer. Researches have shown that both astaxanthin obtained from natural sources and its synthetic counterpart produce satisfactory effects, but studies in humans are limited to natural sources. There is no established nutritional recommendation regarding astaxanthin daily intake but most studies reported beneficial results from a daily intake of 4mg. Thus, this review discusses some aspects of the carotenoid astaxanthin, highlighting its chemical structure and antioxidant activity, and some studies that report its use in humans.Indexing terms: Antioxidants. Astaxanthin. Carotenoids. Chronic diseases. R E S U M O

Carotenoides totais em resíduos do camarão Litopenaeus vannamei

“…Estudos sugerem que, para se obterem os efeitos benéficos da astaxantina, é necessário um consumo diário de cerca de 4 mg deste carotenoide (Parisi et al, 2008;Satoh et al 2009). As cáp-sulas de astaxantina comercializadas em alguns países apresentam concentração variando entre 4 e 20 mg (Seabra & Pedrosa, 2010). Considerando-se os valores obtidos neste estudo, em 100 g de resíduo ou de farinha de camarão, os teores de carotenoides totais corresponderam a 4,27 e 9,85 mg, respectivamente.…”

Total carotenoids and antioxidant activity of fillets and shells (in natura or cooked) of “Vila Franca” shrimp (Litopenaeus Schmitti) in different intervals of storage under freezing

“…The astaxanthin capsules commercialized in some countries have concentration varying between 4 and 20 mg Pedrosa, 2010). Considering the total content of carotenoids on 15 g samples of raw shells of "Vila Franca" shrimp, their level corresponded to 0.498 mg (4,15 µg x 120 mL extract), i.e., 33.2 µg g -1 shrimp waste, so that about 675 g of these shrimp shells could create a capsule with a highest dose of astaxanthin (90% of the content of carotenoids in shell).…”

Antioxidation and anti-ageing activities of different stereoisomeric astaxanthin in vitro and in vivo

“…The antioxidant effect of AST has been associated with the structure of long conjugated chain, hydroxyl group at C3 and C3′ of terminal ring structure, unsaturated ketone (C=O), and α-hydroxy ketones that are composed of hydroxyl and keto groups (Goto et al, 2001;Seabra & Pedrosa, 2010). Different stereoisomers exist because of the two stereogenic carbon atoms at the C-3 and C-3′ positions.…”

“…Therefore they share many general metabolic and physiological functions attributed to carotenoids. However, AST has other peculiar chemical properties owing to its molecular structure (Seabra & Pedrosa, 2010). The presence of hydroxyl and carbonyl functional groups in ketocarotenoids makes AST excellent antioxidants (Dose et al, 2016;Liu & Osawa, 2007).…”