This work addresses the amino acid sequence, structural analysis, biochemical characterization and glycosidase activity of two recombinant α-rhamnosidases, Ram1 and Ram2, from Lactobacillus plantarum WCFS1. The substrate specificity of both enzymes towards the disaccharide rutinose and natural dietary flavonoids naringin and rutin was also determined and compared to that of a commercial multienzyme complex (Pectinex Ultra Passover, PPO). Ram1 is a less acidic- and heat-active enzyme than Ram2 and exhibited a high activity towards pNP-α-L-rhamnopyranoside, but it was unable to hydrolyze neither rutinose, naringin or rutin. In contrast, Ram2 enzyme showed a substrate specificity towards α-(1➔6) glycosidic flavonoids, such as rutin, and the disaccharide rutinose. The mechanism of action of Ram2 towards rutin was elucidated and revealed the potential cost-effective and selective production of the monoglycosylated flavonoid isoquercetin (quercetin-3-O-glucoside). PPO efficiently converted both naringin and rutin into their corresponding aglycones. These findings revealed the potential usefulness of PPO for the improvement of sensory properties of beverages through debittering of citrus juices, as well as the potential use of Ram2 to selectively produce isoquercetin, a highly valued and bioactive flavonoid whose production is not currently affordable.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.11.053 | DOI Listing |
Food Chem X
January 2025
National Institute of Food Science and Technology, University of Agriculture, Faisalabad 38000, Pakistan.
Unlabelled: This study investigates the optimization of bioactive components in thermosonicated black carrot juice using response surface methodology (RSM) and gradient boosting (GB) modeling techniques. Thermosonication, a combination of ultrasound and heat, was applied to enhance the nutritional quality of black carrot juice, which is rich in anthocyanins, phenolic compounds, and antioxidants. The study examined the effects of temperature, processing time, and ultrasonic amplitude on total carotenoid content (TCC), total anthocyanin content (TAC), ferric reducing antioxidant power (FRAP), and total phenolic content.
View Article and Find Full Text PDFBioorg Chem
February 2025
Guangdong Provincial Key Laboratory of Lingnan Specialty Food Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China; Key Laboratory of Green Processing and Intelligent Manufacturing of Lingnan Specialty Food, Ministry of Agriculture, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
An α-l-Rhamnosidase gene with an open reading frame of 3192 bp encoding a 1036-amino acid protein (EhRha) was cloned from Emiliania huxleyi for flavonoid hydrolysis on the cell surface of Pichia pastoris (P. pastoris) strain GS115 by fusing with the anchor protein (AGα1) from Saccharomyces cerevisiae. Fluorescence microscopy and flow cytometry assays revealed that EhRha was successfully displayed on the cell surface of P.
View Article and Find Full Text PDFMol Biotechnol
November 2024
Institute of Horticulture, Xinjiang Academy of Agricultural Sciences, Urumqi, 830000, China.
Seed samples of two types of chickpea (Cicer arietinum Linn.), including variety A (NRCGR-4452) and variety B (local varieties), with different seed colors, were collected every five days for a total of four times during the seed development period. Non-targeted metabolome and transcriptome sequencing were conducted to identify differentially expressed genes and metabolites associated with chickpea seed coat color.
View Article and Find Full Text PDFFront Plant Sci
October 2024
College of Food and Health, Zhejiang Agriculture and Forestry University, Hangzhou, China.
Introduction: is a folk and rare medicinal plant, and specifically, it is distributed in the south, China. To investigate the cumulative properties of its medicinal components, we examined the effect of UV light on flavonoid content and related enzyme activity changes in .
Methods: The leaves and tubers were treated with UV-A, UV-B and UV-C for 1 h, 1L/23D h, 3 h and 3L/21D h (D represents darkness treatment).
J Ethnopharmacol
January 2025
College of Traditional Chinese Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China; Fujian Key Laboratory of TCM Health Status Identification, Fujian University of Traditional Chinese Medicine, Fuzhou, 350122, Fujian, China. Electronic address:
Ethnopharmacological Relevance: As one of the important by-products of Taxus chinensis (Pilg.) Rehder, its fruit (TCF) has a sweet taste, which is commonly used in folklore to make health care wine reputed for enhancing immune function and promoting anti-aging effects, especially popular in the longevity villages of China for a long history. Evidences had showed that Taxus chinensis fruit contained polysaccharides, flavonoids, amino acids and terpenoids, which all were free of toxic compounds, but its medicinal value has not been fully recognized.
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