Natural Products and Biological Activities of Plants from Genus Morus: 2011-2023.

Species of genus Morus (family Moraceae) have been used as traditional medicinal and edible resources since ancient times. Genus Morus has been acknowledged as a promising resource for the exploration of novel compounds with various bioactivities. Phytochemical investigations of the genus have led to the discovery of more than approximately 453 natural products from 2011 to 2023, mainly including flavonoids, Diels-Alder adducts, 2-arylbenzfuran, alkaloids and stilbenes. Bioactive constituents and extracts of this genus displayed a wide range of impressive biological properties including antidiabetic, anti-inflammatory, antioxidant, anti-cancer, hepatoprotective, renoprotective, and some other activities. Herein, the research progress of this genus Morus from 2011 to 2023 on phytochemistry and pharmacology are systematically presented and discussed for the first time. This current review provides the easiest access to the information on genus Morus for readers and researchers in view of enhancing the continuity on research done on this genus.

Chitosan Hydrogel Supplemented with Metformin Promotes Neuron-like Cell Differentiation of Gingival Mesenchymal Stem Cells.

Human gingival mesenchymal stem cells (GMSCs) are derived from migratory neural crest stem cells and have the potential to differentiate into neurons. Metformin can inhibit stem-cell aging and promotes the regeneration and development of neurons. In this study, we investigated the potential of metformin as an enhancer on neuronal differentiation of GMSCs in the growth environment of chitosan hydrogel. The crosslinked chitosan/ß-glycerophosphate hydrogel can form a perforated microporous structure that is suitable for cell growth and channels to transport water and macromolecules. GMSCs have powerful osteogenic, adipogenic and chondrogenic abilities in the induction medium supplemented with metformin. After induction in an induction medium supplemented with metformin, Western blot and immunofluorescence results showed that GMSCs differentiated into neuron-like cells with a significantly enhanced expression of neuro-related markers, including Nestin (NES) and ß-Tubulin (TUJ1). Proteomics was used to construct protein profiles in neural differentiation, and the results showed that chitosan hydrogels containing metformin promoted the upregulation of neural regeneration-related proteins, including ATP5F1, ATP5J, NADH dehydrogenase (ubiquinone) Fe-S protein 3 (NDUFS3), and Glutamate Dehydrogenase 1 (GLUD1). Our results help to promote the clinical application of stem-cell neural regeneration.

High-throughput screening suggests glutathione synthetase as an anti-tumor target of polydatin using human proteome chip.

Polydatin (PD) is a bio-active ingredient with known anti-tumor effects. However, its specific protein targets yet have not been systematically screened, and the molecular anti-tumor mechanism is still unclear. Here, proteomic-chip was efficiently used to screen potential targets of PD. First, we investigated through animal experiment and proteomics studies, and found that polydatin play an important role in tumor cells. Then, the red-green fluorescent of polydatin was compared comprehensively to screen its targets on chip, followed by bioinformatics analysis. Glutathione synthetase (GSS) was selected as candidate research target. After a series of molecular biological experiments GSS was confirmed a target protein for PD in vitro. Moreover, we also found that PD can significantly inhibit the activity of GSS in vitro and live cells. Our findings reveal that PD could be a selective small-molecule GSS enzyme activity inhibitor and GSS could be a potential therapeutic target in cancer.

Iron(II)-Catalyzed Site-Selective Functionalization of Unactivated C(sp3 )-H Bonds Guided by Alkoxyl Radicals.

An alkoxyl radical guided strategy for site-selective functionalization of unactivated methylene and methine C-H bonds enabled by an FeII -catalyzed redox process is described. The mild, expeditious, and modular protocol allows efficient remote aliphatic fluorination, chlorination, amination, and alkynylation of structurally and electronically varied primary, secondary, and tertiary hydroperoxides with excellent functional-group tolerance. The application for one-pot 1,4-hydroxyl functionalization of non-oxygenated alkane substrates initiated by aerobic C-H oxygenation is also demonstrated.

Identification of heat shock protein 27 as a novel autoantigen of Behçet's disease.

OBJECTIVE: The aim of this study was to identify candidate pathogenic autoantigens of Behçet's disease (BD) in pathogen-stimulated target cells. METHODS: First, three cell lines were used as target cells to screen autoantibody. Second, selected target cells were simulated with pathogens. Third, western blotting was used for detecting the auto-antigens in cell extracts. Next, immunoprecipitation was performed and the amino-acid sequences of target antigens were analyzed by LC-MALDI-TOF/TOF. Then, the potential target antigen was expressed, purified, and immunologically confirmed. And finally, an ELISA kit was developed and clinically validated through the assessments of 456 clinical samples with BD. RESULTS: One antigen with a molecular weight of approximately 27-kDa was identified as heat shock protein 27 (HSP27). The reactivity of serum IgG against recombinant human HSP27 was detected in 52 of 91 BD patients (57%), 66 of 92 rheumatoid arthritis (RA) patients (72%), 32 of 90 Sjogren syndrome (SS) patients (36%), 22 of 92 systemic lupus erythematosus (SLE) patients (24%) and 0 of 91 healthy controls (HC). The reactivity of BD serum IgG antibodies against HSP27 was significantly higher than SLE (P<0.0001) SS (P<0.0001) and HC (P<0.0001). CONCLUSIONS: This study identified HSP27 as a candidate endothelial cell autoantigen of BD, which is interesting and probably worth further exploration.

[Semi-in vitro biosynthesis of cryptic lanthipeptide CLA 124 from Streptomyces clavuligerus].

OBJECTIVE: To obtain the cryptic lanthipeptide from Streptomyces clavuligerus by semi-in vitro biosynthesis that is a novel method for mining lanthipeptides resource from Streptomyces. METHODS: The core peptide of cryptic lanthipeptide was modified in E. coli by nisin modification system, and purified by affinity chromatography and High Performance Liquid Chromatography (HPLC). After the leader peptide was removed, the core peptide was obtained and its dehydration and cyclic structure were analyzed by MALDI-TOF MS and tandem MS. RESULTS: A novel lanthipeptide named CLA 124 with 4-fold dehydration 2 thioether bridges and one disulfide bridge was produced. CONCLUSION: Cryptic lanthipeptides from Streptomyces could be produced by semi-in vitro biosynthesis.

Thiosulfate transfer mediated by DsrE/TusA homologs from acidothermophilic sulfur-oxidizing archaeon Metallosphaera cuprina.

Conserved clusters of genes encoding DsrE and TusA homologs occur in many archaeal and bacterial sulfur oxidizers. TusA has a well documented function as a sulfurtransferase in tRNA modification and molybdenum cofactor biosynthesis in Escherichia coli, and DsrE is an active site subunit of the DsrEFH complex that is essential for sulfur trafficking in the phototrophic sulfur-oxidizing Allochromatium vinosum. In the acidothermophilic sulfur (S(0))- and tetrathionate (S4O6(2-))-oxidizing Metallosphaera cuprina Ar-4, a dsrE3A-dsrE2B-tusA arrangement is situated immediately between genes encoding dihydrolipoamide dehydrogenase and a heterodisulfide reductase-like complex. In this study, the biochemical features and sulfur transferring abilities of the DsrE2B, DsrE3A, and TusA proteins were investigated. DsrE3A and TusA proved to react with tetrathionate but not with NaSH, glutathione persulfide, polysulfide, thiosulfate, or sulfite. The products were identified as protein-Cys-S-thiosulfonates. DsrE3A was also able to cleave the thiosulfate group from TusA-Cys(18)-S-thiosulfonate. DsrE2B did not react with any of the sulfur compounds tested. DsrE3A and TusA interacted physically with each other and formed a heterocomplex. The cysteine residue (Cys(18)) of TusA is crucial for this interaction. The single cysteine mutants DsrE3A-C(93)S and DsrE3A-C(101)S retained the ability to transfer the thiosulfonate group to TusA. TusA-C(18)S neither reacted with tetrathionate nor was it loaded with thiosulfate with DsrE3A-Cys-S-thiosulfonate as the donor. The transfer of thiosulfate, mediated by a DsrE-like protein and TusA, is unprecedented not only in M. cuprina but also in other sulfur-oxidizing prokaryotes. The results of this study provide new knowledge on oxidative microbial sulfur metabolism.

Profiling of endogenous serum phosphorylated peptides by titanium (IV) immobilized mesoporous silica particles enrichment and MALDI-TOFMS detection.

Phosphorylation is one of the most important post-translational modifications of proteins, which modulates a wide range of biological functions and activities of proteins. The phosphorylation of proteins is also associated with the pathway of cancer cells. We have previously enriched the low molecular weight proteome from human plasma based on the combination of size exclusion and adsorption mechanism by using highly ordered mesoporous silica particles. Herein, highly ordered mesoporous silica particles were modified with titanium phosphonate to selectively capture the phosphopeptides from complex peptide and protein mixtures. The limit of detection for phosphopeptides from beta-casein and standard phosphopeptide spiked in human serum was as low as 1.25 fmol based on MALDI-TOFMS detection. The modified mesoporous silica particles were further used to enrich phosphopeptides from serum of hepatocellular carcinoma patients and healthy individuals and then analyzed with MALDI-TOFMS. The combination of isobaric tagging for relative and absolute quantitation labeling with MALDI-TOFMS/MS was further applied to validate the serum phosphopeptide profiling result of MALDI-TOFMS. The profiling of the serum phosphopeptides between the cancer patients and healthy persons was distinguishingly different, which indicated the potential ability of this technique for cancer diagnosis and biomarker discovery. The approach developed here would be applicable to other biological samples and a wide variety of diseases.

Reactions of platinum cluster ions with benzene.

In this work, the cation and anion products of the reactions between platinum clusters produced by laser ablation and the benzene molecules seeded in argon have been studied using a high-resolution reflectron time-of-flight mass spectrometer (RTOFMS). The dominant cation products are [C(6n)H(6n - k)](+) and [Pt(m)(C(6)H(6))(n)](+) complexes, while the dominant anion products are dehydrogenated species, [C(6)H(5)PtH](-), [PtC(12)H(k)](-) and [Pt(m)C(6)H(4) . . . (C(6)H(6))(n)](-), etc. Some important intermediate structures ([PtC(6)H(6)](+), [Pt(C(6)H(6))(2)](+), [Pt(2)(C(6)H(6))(3)](+), [C(6)H(5)PtH](-), [Pt(2)C(6)H(4)](-), [Pt(3)C(6)H(4)](-) and [Pt(4)C(6)H(4)](-)) have been analyzed using density functional theory (DFT) calculations. Different reaction mechanisms are proposed for platinum cluster cations and anions with benzene, respectively.