Identification of tyrosinase inhibitors in defatted seeds of evening primrose (Oenothera biennis L.) by affinity-labeled molecular networking.

The defatted seeds of evening primrose (DE), a by-product of evening primrose oil extraction, are currently underutilized. This study aimed to valorize DE by examining its effects on melanogenesis and tyrosinase activity in zebrafish embryos and in vitro, and an innovative affinity-labeled molecular networking workflow was proposed for the rapid identification of tyrosinase inhibitors in DE. Our results indicated DE significantly reduced melanin content (53.3 % at 100 µg/mL) and tyrosinse activity (80.05 % for monophenolase and 70.40 % for diphenolase at 100 µg/mL). Furthermore, through the affinity-labeled molecular networking approach, 20 compounds were identified as potential tyrosinase inhibitors within DE, predominantly flavonoids and tannins characterized by catechin and galloyl substructures. Seven of these compounds were isolated and their inhibitory effects on tyrosinase were validated using functional assays. This study not only underscores the potential of DE as a rich source of natural tyrosinase inhibitors but also establishes the effectiveness of affinity-labeled molecular networking in pinpointing bioactive compounds in complex biological matrices.

Miniaturized centrifugation accelerated pipette-tip matrix solid-phase dispersion based on poly(deep eutectic solvents) surface imprinted graphene oxide composite adsorbent for rapid extraction of anti-adipogenesis markers from Solidago decurrens Lour.

Overweight and obesity are the causes of many diseases and have become global "epidemics". Research on natural active components with anti-adipogenesis effects in plants has aroused the interest of researchers. One of the most critical problems is establishing sample preparation and analytical techniques for quickly and selectively extracting and determining the active anti-adipogenesis components in complex plant matrices for developing new anti-adipogenic drugs. In this study, a new poly(deep eutectic solvents) surface imprinted graphene oxide composite (PDESs-MIP/GO) with high selectivity for phenolic acids was prepared using deep eutectic solvents as monomers and crosslinkers. A miniaturized centrifugation-accelerated pipette-tip matrix solid-phase dispersion method (CPT-MSPD) with PDESs-MIP/GO as adsorbent, coupled with high-performance liquid chromatography, was further developed for the rapid determination of anti-adipogenesis markers in Solidago decurrens Lour. (SDL). The established method was successfully used to determination anti-adipogenesis markers in SDL from different regions, with the advantages of accuracy (recoveries: 94.4 - 115.9 %, RSDs ≤ 9.8 %), speed (CPT-MSPD time: 11 min), selectivity (imprinting factor: ∼2.0), and economy (2 mg of adsorbent and 1 mL of solvents), which is in line with the current advanced principle of "3S+2A" in analytical chemistry.

Ionic liquid-organic-functionalized ordered mesoporous silica-integrated dispersive solid-phase extraction for determination of plant growth regulators in fresh Panax ginseng.

The massive accumulation of plant growth regulators (PGRs) in Panax ginseng causes serious harm to human health. A new analytical method for the simultaneous determination of multiple PGRs in 19 types of fresh Panax ginseng is developed by a new designed wool cluster-inspired ionic liquid-functionalized ordered mesoporous silica-integrated dispersive solid-phase extraction coupled to high performance liquid chromatography (IL-WFOMS-I-DSPE-HPLC). The proposed method combines the advantages of the multiple adsorption mechanisms, high mass transfer rate and large adsorption capacity of the synthesized IL-WFOMS adsorbent with the safe, convenient operation of the new designed I-DSPE method. Under optimized conditions, the recoveries at three spike levels were in a range of 77.6-98.3% for 3-indole acetic acid (IAA), 3-indole propionic acid (IPA), 3-indole butyric acid (IBA), and 1-naphthaleneacetic acid (NAA) with the relative standard deviations (RSD) ≤8.6%, n = 3. This method exhibits the advantages of safety, convenience, reliability, and has great potential for simultaneous determination of multiple trace PGRs in complex sample matrices.