Dong Zhang

In recent years, active monomers derived from Chinese herbal medicine and their derivatives have attracted significant attention in the field of skincare product development. Artemisinin and its derivatives, including dihydroartemisinin (DHA), exhibit diverse pharmacological activities such as anti-inflammatory, antibacterial, immunomodulatory, and antitumor effects, showing promising therapeutic potential in skin-related diseases. However, systematic studies on artemisinins in cosmetics are lacking. This study aimed to evaluate the cosmetic potential of DHA by investigating its anti-aging, anti-hair loss, antibacterial, whitening, and anti-glycation activities. Results showed that DHA exhibits multiple biological activities: DHA exhibits anti-aging activity by promoting collagen I synthesis in HDF cell, exhibits anti-hair loss effect by modulating VEGF and DKK1 expression in DPC cell, exhibits antibacterial activity against Malassezia furfur, exhibits whitening activity by suppressing melanin synthesis, and exhibits anti-glycation activity by suppressing glycation reactions. Overall, with the broad biological activities, we believe that DHA holds encouraging promise in the cosmetics industry.

Fatty acids play fundamental structural, metabolic, functional, and signaling roles in all biological systems. Altered fatty acid levels and metabolism have been associated with many pathological conditions. Chemical probes have greatly facilitated biological studies on fatty acids. Herein, we report the development and characterization of an alkynyl‐functionalized long‐chain fatty acid‐based sulfonyl fluoride probe for covalent labelling, enrichment, and identification of fatty acid‐associated proteins in living cells. Our quantitative chemical proteomics show that this sulfonyl fluoride probe targets diverse classes of fatty acid‐associated proteins including many metabolic serine hydrolases that are known to be involved in fatty acid metabolism and modification. We further validate that the probe covalently modifies the catalytically or functionally essential serine or tyrosine residues of its target proteins and enables evaluation of their inhibitors. The sulfonyl fluoride‐based chemical probe thus represents a new tool for profiling the expression and activity of fatty acid‐associated proteins in living cells.

Dihydroartemisinin (DHA) and its’ derivatives have been employed as the most powerful first-line drugs for malarial treatment for several decades. The metabolism of DHA has not been studied clearly. Previous reports were focused on the pharmacokinetics procedure of DHA in healthy rats. The metabolites of DHA in red blood cells (RBC), especially in the RBC from Plasmodium-infected models, have rarely been studied. The Plasmodium species parasitize inside RBC, and these cells should be the final place where DHA performs its activity. In this study, the profile of DHA metabolites in biosample (blood, plasma, and RBC) of the infected and healthy mice was investigated with UPLC-Q-TOF-MS and UNIFI platform to gain insight into DHA metabolism. Results show that a total of 25 metabolites were successfully identified in infected (30 in healthy) blood, 27 in infected (27 in healthy) plasma, and 15 in infected (22 in healthy) RBC. Results show that hydroxylation, OH-dehydration, and glucuronidation reactions were important in the metabolic pathway in vivo. Significantly, DHA metabolites inside RBC were identified for the first time. 8-Hydroxy (8-OH) DHA, 4α-OH deoxy ART, and 6β-OH deoxy ART were identified in vivo for the first time.

Ultraperformance convergence chromatography is an environmentally friendly analytical technique for dramatically reducing the use of organic solvents compared to conventional chromatographic methods. In this study, a rapid and sensitive ultraperformance convergence chromatography method was firstly established for quantification of thymol and carvacrol, two positional isomers of a major bioactive in the volatile oil of Thymi herba, the dried leaves and flowers of Thymus mongolicus or Thymus przewalskii, known in China as “Dijiao.” Using a Trefoil^TM CEL1 column, thymol and carvacrol were separated in less than 2.5 min and resolution was enhanced. The method was validated with respect to precision, accuracy, and linearity according to the National Medical Products Administration guidelines. The optimized method exhibited good linear correlation (r = 0.9998−0.9999), excellent precision (relative standard deviations (RSDs) < 1.50%), and acceptable recoveries (87.29–102.89%). The limits of detection for thymol and carvacrol were 1.31 and 1.57 ng/L, respectively, while their corresponding limits of quantification were 2.63 and 3.14 ng/L. Finally, the quantities of the two compounds present in 16 T. mongolicus and four T. przewalskii samples were successfully evaluated by employing the developed method. It is hoped that the results of this study will serve as a guideline for the quality control of Thymi herba.

A simple and effective method for the simultaneous quantitative analysis of six caffeoylquinic acids (CAs) in Matricaria chamomilla L. (M. chamomilla) using high-performance liquid chromatography (HPLC) with diode-array detection (DAD) was established. The chromatographic separation was performed on a Waters XBridge Shield RP C₁₈ column (4.6 mm × 250 mm, 5 μm) with the mobile phase of acetonitrile (0.5% phosphoric acid) and water (0.5% phosphoric acid) using a gradient elution at a flow rate of 1.0 mL/min and UV detection at 327 nm. The correlation coefficients of all analytes were 0.999, and the results showed excellent linearity. The lower limits of detection (LLOD) and quantification (LLOQ) of all analytes fall within the range of 0.014∼0.017 μg/mL and 0.068∼0.086 μg/mL, respectively. The extraction recoveries of all analytes fall within the range of 100.74%∼101.55%, with relative standard deviation not exceeding 2.83%. The intraday and interday precisions fall within the range of 0.03%∼0.65% and 0.02%∼0.09%, respectively. This validated method was successfully applied to the investigation of 34 samples of M. chamomilla collected from different geographical areas. The results showed that the established method is appropriate for the analysis of the six CAs in M. chamomilla and helpful for quality assessment of capitula of M. chamomilla (CMC), whole herb of M. chamomilla (WHMC), and related herbal formulas.

10-deoxoartemisinin is a semisynthetic derivative of artemisinin that lacks a lactone carbonyl group at the 10-position, and has stronger antimalarial properties than artemisinin. However, 10-deoxoartemisinin has limited utility as a therapeutic agent because of its low solubility and bioavailability. Hydroxylated 10-deoxoartemisinins are a series of properties-improved derivatives. Via microbial transformation, which can hydroxylate 10-deoxoartemisinin at multiple sites, the biotransformation products of 10-deoxoartemisinin have been investigated in this paper. Using ultra-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS^E) combined with UNIFI software, products of microbial transformation of 10-deoxoartemisinin were rapidly and directly analyzed. The hydroxylation abilities of nine microorganisms were compared using this method. All of the microorganisms evaluated were able to hydroxylate 10-deoxoartemisinin, and a total of 35 hydroxylated products were identified. These can be grouped into dihydroxylated 10-deoxoartemisinins, monohydroxylated 10-deoxoartemisinins, hydroxylated dehydrogenated 10-deoxoartemisinins, and hydroxylated hydrogenated 10-deoxoartemisinins. Cunninghamella echinulata and Cunninghamella blakesleeana are able to hydroxylate 10-deoxoartemisinin, and their biotransformation products are investigated here for the first time. Cunninghamella elegans CICC 40250 was shown to most efficiently hydroxylate 10-deoxoartemisinin, and could serve as a model organism for microbial transformation. This method could be used to generate additional hydroxylated 10-deoxoartemisinins for further research.

Artemisinin (ART) is a highly effective antimalarial agent isolated from the traditional Chinese herb Qinghao. Metabolism of ART and its derivatives in the body is one of the most pressing issues for pharmaceutical scientists. Herein, an efficient in vitro microorganism model for simulation of metabolism of ART in vivo was developed employing Cunninghamella elegans. Metabolites in the microbial transformation system and plasma of mice pre-administrated ART orally were analyzed by ultra-performance liquid chromatography (UPLC)-electrospray ionization (ESI)-quadrupole time-of-flight (Q-TOF)-mass spectrometry (MS^E) combined with UNIFI software. Thirty-two metabolites were identified in vitro and 23 were identified in vivo. After comparison, 16 products were found to be common to both models including monohydroxylated ART, dihydroxylated ART, deoxyartemisinin, hydroxylated deoxyartemisinin, hydroxylated dihydroartemisinin (DHA), and hydroxylated deoxy-DHA. These results revealed that C. elegans CICC 40250 functioned as an appropriate model to mimic ART metabolism in vivo. Moreover, an overall description of metabolites of ART from C. elegans CICC 40250 has been provided. Notably, DHA was detected and identified as a metabolite of ART in mouse plasma for the first time.