Publications by authors named "Yongkai Ma"

Flavan-3-ols are the most found flavonoid compounds in the human diet. Polymeric and monomeric flavan-3-ols reach the colonic region intact, where the gut microbiota utilizes them as substrates. In this research work, we investigated the pattern of colonic metabolites associated with flavan-3-ols, conducting a comprehensive analysis that combined (un)targeted metabolomics and in vitro colonic models.

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The quorum sensing (QS) inhibition effect of methyl N-methylanthranilate (MMA) from Pericarpium Citri Reticulatae Chachiensis against foodborne pathogen Pseudomonas aeruginosa was reported for the first time. MMA effectively attenuated QS related virulence factors production and biofilm formation, while suppressed expression of a dozen of QS related genes. Untargeted LC-MS metabolomics revealed 108 significantly altered metabolites after MMA treatment.

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'Chachiensis' (PCR-Chachiensis), the pericarps of Blanco cv. Chachiensis, is a food condiment and traditional medicine in southeast and eastern Asia. Its rich and various bacterial community awaits exploration.

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Due to the potential of antioxidants to scavenge free radicals in human body, it is important to be able to prepare antioxidant peptides that meet the industrial requirements for cosmetics and food. Here, we determined in vivo/in vitro activities of antioxidant peptide from (PFAOP) prepared by bio-fermentation method. The antioxidant property test results showed the DPPH, hydroxyl, superoxide radical-scavenging, and cellular antioxidant activity.

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Previously, we determined that diallyl disulfide (DADS) from garlic oil can inhibit PAO1 pathogenic factors by inactivating the transcription of key genes from three quorum sensing (QS) systems (, , and ) based on the effects of DADS on growth, virulence factor production (elastase, pyocyanin, biofilm, and swarming motility), and RNA transcription (real-time q-PCR). To further investigate the mechanisms underlying the inhibition of the three QS systems by DADS, high-throughput RNA and proteome sequencing techniques were used to study differences in the transcriptional and proteome expression of PAO1 following treatment with DADS. The RNA-seq and proteomic data are available via NCBI Gene Expression Omnibus database with accession number GSE118801 and ProteomeXchange with identifier PXD011144, respectively.

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The aim of this study was to establish a system for the efficient expression and purification of new subtype of antioxidant peptide from meat (NPFMAP), which is designed by molecular modification technology based on the sequence of purified and identified antioxidant peptide from meat (PFMAP, ---------), and to better understand the relationship between structure and antioxidant activity. Meanwhile, gene codon usage was optimized and the glutathione -transferase (GST) tag of pGEX-6P-1 was added to facilitate expression and purification NPFMAP in . The results of antioxidant activity assay in vitro showed a higher antioxidant activity in NPFMAP than that in enzymatic hydrolysis digested or chemically synthesized PFMAP.

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Garlic oil can disrupt the quorum sensing (QS) pathways of the opportunistic pathogen Pseudomonas aeruginosa; however, the underlying mechanisms for this effect are unclear. Diallyl disulfide (DADS) is one of the most abundant sulfur-containing compounds in garlic oil. This study investigated the effects of DADS on the growth, virulence factor production (elastase, pyocyanin, biofilm, and swarming motility), and essential gene expression of P.

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Antioxidant peptides from Pinctada fucata are ubiquitous in nature and can be utilized as ingredients in cosmetics or functional foods to positively regulate oxidative species in the human body against oxidation. Here, mutated peptides and a homologous series of peptides were designed and prepared, based on the original peptide sequence of an antioxidant peptide from Pinctada fucata meat (PFMAP), to better understand the structural relationships, including primary structure, spatial conformation and activity. The results showed that the antioxidant activity factors in order of importance were spatial conformation, amino acid sequence, amino acid position, amino acid composition, peptide chain length and degree of side-chain amino acid glycosylation.

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An antioxidant peptide derived from meat using an Alcalase2.4L enzymatic hydrolysis method (named AOP) and identified by LC-TOF-MS has promising clinical potential for generating cosmetic products that protect skin from sunshine. To date, there have been few published studies investigating the structure-activity relationship in these peptides.

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