Identification of microbial carotenoids and isoprenoid quinones from Rhodococcus sp. B7740 and its stability in the presence of iron in model gastric conditions

• Published in: Food chemistry Vol. 240; pp. 204 - 211
• Main Authors: Chen, Yashu, Xie, Bijun, Yang, Jifang, Chen, Jigang, Sun, Zhida
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2018
• Subjects: Carotenoids - isolation & purification; HSCCC; Iron; Isorenieratene; LC-MS/MS & HRMS; Microbial carotenoids and quinones; Model gastric condition; Quinones - isolation & purification; Rhodococcus; Tandem Mass Spectrometry; Isorenieratene; LC-MS/MS & HRMS; Model gastric condition; HSCCC; Microbial carotenoids and quinones
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2017.06.067

•Isorenieratene was identified by HPLC-DAD-MS2 combined with HSCCC and HRMS.•Isorenieratene is a most stable carotenoid with promising health benefits.•Three rare aromatic carotenoids were discovered in Rhodococcus sp. B7740. Rhodococcus sp. B7740 is a newfound bacterium which was isolated from 25m deep seawater in the arctic. In this paper, Rhodococcus sp. B7740 was firstly discovered to produce abundant natural isoprenoids, including ubiquinone-4(UQ-4), 13 kinds of menaquinones, three rare aromatic carotenoids and more than one common carotenoid. These compounds were identified by UV–Visible, HPLC-APCI-MS/MS and HRMS spectra. Results demonstrated that Rhodococcus sp. B7740 might be a worthy source of natural isoprenoids especially for scarce aromatic carotenoids. Among them, isorenieratene with 528.3762Da (calculated for 528.3756Da, error: 1.1ppm), a carotenoid with aromatic ring, was purified by HSCCC. The stability of isorenieratene under the mimical gastric conditions was measured compared with common dietary carotenoids, β-carotene and lutein. Unlike β-carotene and lutein, isorenieratene exhibited rather stable in the presence of free iron or heme iron. Its high retention rate in gastrointestinal tract after ingestion indicates the benefits for health.