Vitamin K in human health and metabolism: A nutri-genomics review

A metal-complex based chemosensor for the detection of riboflavin and folate

The vitamins of riboflavin and folate are necessary nutrients for maintaining the proper functioning of human body. Riboflavin and folate deficiency will cause nerve damage, leading to peripheral neuritis, depression, tongue inflammation and other diseases. The sensitive detection of riboflavin and folate keeps its significance for patients and food quality control. In this study, a quinoline-pyridine-combined chemosensor (HQ-TPE) modified by tetraphenylethene was developed. After chelating Cd2+, the chemosensor exhibited high selectivity and sensitivity for riboflavin and folate. Moreover, it can discriminate the two different vitamins through different fluorescent responses, which should arise from the different intermolecular π-π interactions between the sensor HQ-TPE and the analyte upon coordination of riboflavin or folate with Cd2+. More importantly, the chemosensor could be used in visual semi-quantitative determination of riboflavin and folate in real samples (milk and lettuce). Therefore, the sensor presented here will not only be a powerful tool for the detection of riboflavin and folate, but also provides a new template for the design of metal complex as fluorescent sensor.

Label-free detection of vitamin B by two-step enhanced Raman technique using dynamic borohydride-reduced silver nanoparticles

A creatively designed novel two-step enhancement technique is presented in which B vitamin molecules are dynamically adsorbed onto the surface of silver nanoparticles by sodium borohydride, followed by local plasmon resonance in the presence of cations (calcium ions), ultimately achieving synergistic chemical and physical enhancement on the same molecule and constructing a "surface hot spots" two-step enhancement platform for vitamin detection. The Raman signal of the promoted vitamin molecule is enhanced by nine orders of magnitude. In a subsequent study it was observed that the vitamin B2 molecules were in a near-vertical image on the surface of the silver nanoparticles, which may also contribute to the Raman signal enhancement. Combined with deep learning techniques, the method has been successfully applied to the detection of B vitamins in body fluids. As an accurate, rapid, reproducible, non-invasive, and versatile assay platform, it holds great promise for the intelligent identification of trace B molecules in food, pharmaceuticals, and the human body.

Association among VKORC1 rs9923231, CYP4F2 rs2108622, GGCX rs11676382 polymorphisms and acute ischemic stroke

Acute ischemic stroke is a major cause of morbidity and mortality worldwide, and genetic factors play a role in the risk of stroke. Single nucleotide polymorphisms (SNPs) in the VKORC1, CYP4F2, and GGCX genes have been linked to clinical outcomes, such as bleeding and cardiovascular diseases. This study aimed to investigate the association between specific polymorphisms in these genes and the risk of developing the first episode of acute ischemic stroke in patients without a known embolic source. This retrospective, cross-sectional, observational, analytical, case-control study included adult patients diagnosed with acute ischemic stroke. The SNPs in VKORC1 rs9923231, CYP4F2 rs2108622, GGCX rs11676382 genes were genotyped and analyzed together with the demographic and clinical factors of the 2 groups of patients. The presence of SNPs in VKORC1 or CYP4F2 genes significantly increased the risk of ischemic stroke in the context of smoking, arterial hypertension, and carotid plaque burden. The multivariate logistic model revealed that smoking (odds ratio [OR] = 3.920; P < .001), the presence of carotid plaques (OR = 2.661; P < .001) and low-density lipoprotein cholesterol values >77 mg/dL (OR = 2.574; P < .001) were independently associated with stroke. Polymorphisms in the VKORC1 and CYP4F2 genes may increase the risk of ischemic stroke in patients without a determined embolic source. Smoking, the presence of carotid plaques, and high low-density lipoprotein cholesterol levels were reconfirmed as important factors associated with ischemic stroke.

Determination of vitamin K in infant formulas by liquid chromatography-online electrochemical reduction based on porous Pt/Ti electrode-fluorescence detection

A highly sensitive and selective HPLC method for the determination of vitamin K vitamers including phylloquinone (PK) and menaquinones (MK-4) in infant formulas is described. The K vitamers were quantified with a fluorescence detector after online post-column electrochemical reduction occurring in a laboratory-made electrochemical reactor (ECR) equipped with platinum plated porous titanium (Pt/Ti) electrodes. The morphology of the electrode showed that the grain size of Pt was homogeneous and well plated on the porous Ti substrate, resulting in largely improved electrochemical reduction efficiency due to the large specific surface area. In addition, the operation parameters such as mobile phase/supporting electrolyte and working potential were optimized. The detection limits of PK and MK-4 were 0.81 and 0.78 ng g^-1. Infant formula varying in stages were detected, showing PK ranged from 26.4 to 71.2 µg/100 g, while MK-4 was not detected.

Prenylation: A Critical Step for Biomanufacturing of Prenylated Aromatic Natural Products

Prenylated aromatic natural products (PANPs) have received much attention due to their biomedical benefits for human health. The prenylation of aromatic natural products (ANPs), which is mainly catalyzed by aromatic prenyltransferases (aPTs), contributes significantly to their structural and functional diversity by providing higher lipophilicity and enhanced bioactivity. aPTs are widely distributed in bacteria, fungi, animals, and plants and play a key role in the regiospecific prenylation of ANPs. Recent studies have greatly advanced our understanding of the characteristics and application of aPTs. In this review, we comment on research progress regarding sources, evolutionary relationships, structural features, reaction mechanism, engineering modification, and application of aPTs. Particular emphasis is also placed on recent advances, challenges, and prospects about applications of aPTs in microbial cell factories for producing PANPs. Generally, this review could provide guidance for using aPTs as robust biocatalytic tools to produce various PANPs with high efficiency.