Carotenoids from the Far-East Bivalve Mollusk Mactra chinensis

Abstract

The phylum Mollusca is the second largest phylum in the animal world and currently numbers 130,000 species living in marine and fresh waters and terrestrial habitats. Representatives of Gastropoda and Bivalvia make up 95% (>95,000 species) of the seven mollusk classes. The majority of them feed primarily on algae rich in carotenoids and pigments that accumulate in mollusk body tissues. A part of the carotenoids is metabolized in vivo in mollusks to vitamin A derivatives. Carotenoids from marine organisms are highly interesting to biochemists and pharmacologists in the search for natural chemicals that can have practical applications as drugs [1]. For example, it was found that fucoxanthin possessed antioxidant [2, 3], antitumor, and anticarcinogenic activity [4][5][6]. Carotenoids are used in the food industry as natural food additives and yellow, red, and orange dyes [7]. Food products such as ice cream, macaroni, soups, jams, jelly, juice, cream, cheese, margarine, mayonnaise, etc. are colored yellow or orange as necessary after adding carotenoids, which can be extracted from inedible parts of the mollusks for use in the food industry. Studies of the carotenoid compositions of marine organisms including mollusks are currently critical [8].Mactra chinensis (Mactridae) is a bivalve mollusk and Asian Pacific subboreal species that inhabits the Sea of Japan (on the shores of Primorye, from Poset Bay to Olga Bay and to the west of Sakhalin), the Sea of Okhotsk, the South Kuril shallows, and the Yellow and East-China Seas. M. chinensis settles in sandy bottoms at depths from 1 to 15 m with water temperatures up to 23.5°C [9,10].The goal of the present work was to study the carotenoid composition from organs of the Far-East bivalve mollusk M. chinensis.A weighed portion of tissue (0.5-1.0 g) was homogenized in a mortar with 10 times the volume of Me 2 CO (5-10 mL). The homogenate was filtered through a Schott filter using a water aspirator. The residue was transferred to a mortar for repeated extraction by Me 2 CO (5 mL) in order to extract completely the carotenoids. The residue on the filter was rinsed with Me 2 CO until the rinsings were colorless. Carotenoids were transferred into hexane by combining and mixing the Me 2 CO extracts in a separatory funnel with hexane (5 mL) and carefully treating with aqueous NaCl solution (150 mL, 5%) in order to separate hexane and aqueous layers. The extract was washed with a small (20-30 mL) amount of distilled H 2 O in order to remove traces of Me 2 CO and dried over anhydrous Na 2 SO 4 for 1 d. The hexane solution was evaporated in a rotary evaporator at 40°C and dissolved in the minimum volume of i-PrOH for HPLC analysis. Carotenoids were saponified by treating an aliquot of the alcohol solution with an equal amount of NaOH solution (5%) in EtOH and storing in a dark place for 12 h.Compounds were identified by comparing retention times and UV-Vis spectra with those of standards. HPLC used an LC-20A HPLC (Shimadzu, Japan) equipped with a Zorbax ODS column (250 mm u 4.6 mm) us...

Differential responses to low salinity on gene expression, physiological and biochemical indexes between the golden and brown noble scallopsChlamys nobilis

“…However, animals cannot synthesize CAR by themselves and must accumulate CAR in their body from their diet. Many molluscs, such as gastropods, bivalves and cephalopods, are rich in CAR (Kantha, ), and many of them are also important resources of CAR for humans and animals (Tabakaeva, Tabakaev, & Zadorozhnyi, ; Vershinin, ).…”