Activating nickel foam with trace titanium oxide for enhanced water oxidation.

Nickel-based electrocatalysts for water oxidation suffer from low activity and poor stability. In this work, 0.015 mg cm-2 TiO2 nanosheets anchored on Ni foam addressed these problems after electrochemical activation. In situ investigations, including Raman spectra, corroborated the enhanced generation of highly active Ni(III)-O-O species on Ni foam in the presence of trace TiO2.

Novel Oxidation Oligomer of Chlorogenic Acid and (-)-Epigallocatechin and Its Quantitative Analysis during the Processing of Keemun Black Tea.

Not only do flavan-3-ols participate in the formation of chromogenic oxidation products such as theaflavins, but chlorogenic acid (3-caffeoylquinic acid, CQA) is also involved in the enzymatic oxidation during black tea processing. The critical oxidation product of CQA and (-)-epigallocatechin (EGC) were identified as an adduct containing benzobicyclo[3.2.2]nonenone structure, which was named as the dichlorogeniccatechin (DCGC) oligomer. It was composed of two molecules of CQA and one molecule of EGC. The effects of the initial reactant ratio and reaction time on the generation of DCGC were also analyzed. A high proportion of CQA promoted the production of DCGC, but a high proportion of EGC inhibited the DCGC formation. In addition, the content of DCGC in Keemun black tea during processing was determined. The content of DCGC highly increased after withering but decreased after drying. This study provides a new perspective for the investigation of other oxidation oligomers in black tea.

[Chemical constituents of diterpenoids from Boswellia carterii].

This paper explored the chemical constituents of Boswellia carterii by column chromatography on silica gel, Sephadex LH-20, ODS column chromatography, and semi-preparative HPLC. The structures of the compounds were identified by physicochemical properties and spectroscopic data such as infrared radiation(IR), ultra violet(UV), mass spectrometry(MS), and nuclear magnetic resonance(NMR). Seven diterpenoids were isolated and purified from n-hexane of B. carterii. The isolates were identified as(1S,3E,7E,11R,12R)-11-hydroxy-1-isopropyl-4,8,12-trimethyl-15-oxabicyclo[10.2.1]pentadeca-3,7-dien-5-one(1),(1R,3S,4R,7E,11E)-4,8,12,15,15-pentamethyl-14-oxabicyclo[11.2.1]hexadeca-7,11-dien-4-ol(2), incensole(3),(-)-(R)-nephthenol(4), euphraticanoid F(5), dilospirane B(6), and dictyotin C(7). Among them, compounds 1 and 2 were new and their absolute configurations were determined by comparison of the calculated and experimental electronic circular dichroisms(ECDs). Compounds 6 and 7 were obtained from B. carterii for the first time.

Platelet-inhibitory phenolic constituents from the fruits of Daemonorops draco.

Eight previously undescribed phenolic compounds, dracoropins A - H (1-8), along with two known analogues (9 and 10) were isolated from the fruits of Daemonorops draco. Four pairs of isomers (1a/1b, 2a/2b, 3a/3b, and 4a/4b) were resolved by using chiral-phase HPLC separation. Their structures, including the absolute configurations of the resolved isomers, were elucidated by analysis of spectroscopic data (1D and 2D NMR, IR, and HRESIMS), single-crystal X-ray diffraction, and electronic circular dichroism (ECD) calculations. Compounds 1, 2, and 3 bear a rare 2-phenylbenzo[d]-1,3-dioxepine skeleton. All the isolates were evaluated for their inhibitory activity against ATP release in thrombin-activated platelets. Compounds 2b, 3a, and 6 could significantly inhibit ATP release in thrombin-activated platelets.

Isoquinoline alkaloids from Corydalis edulis Maxim. Exhibiting insulinotropic action.

Eleven undescribed isoquinoline analogues, namely edulisines A-K, along with sixteen known alkaloids, were isolated from the whole plants of Corydalis edulis. The structures of the isolated alkaloids were established on the basis of extensive spectroscopic data (1D and 2D NMR, UV, IR, and HRESIMS). Their absolute configurations were determined by single-crystal X-ray crystallographic analysis and ECD. Compounds (+)-1 and (-)-1 are a pair of undescribed isoquinoline alkaloids bearing a unique coupled pattern of coptisine and ferulic acid via Diels-Alder [4 + 2] cycloaddition, while compounds (+)-2 and (-)-2 feature benzo [1,2-d:3,4-d]bis [1,3]dioxole moiety. Compounds (+)-2, (-)-2, (-)-5, 10, 13, 15, 20, 22, and 23 significantly triggered the secretion of insulin in the HIT-T15 cells at a concentration of 40 µM.

FTR33, a member of fish-specific TRIM (finTRIM) subfamily, regulates negatively type I IFN antiviral immunity in zebrafish.

In mammals, the tripartite motif (TRIM) proteins have been identified as critical factors involved in various cellular processes, including antiviral immunity. In teleost fish, a subfamily of fish-specific TRIM (finTRIM, FTR) has emerged in genus- or species-specific duplication. In this study, a finTRIM gene, called ftr33, was identified in zebrafish (Danio rerio), and phylogenic analysis revealed that FTR33 is closely related with zebrafish FTR14. The FTR33 protein contains all conservative domains reported in other finTRIMs. The ftr33 has a constitutive expression in embryos and in tissues/organs of adult fish, and its expression can be induced following spring viremia of carp virus (SVCV) infection and interferon (IFN) stimulation. The overexpression of FTR33 significantly downregulated the expression of type I IFNs and IFN-stimulated genes (ISGs) both in vitro and in vivo, respectively, leading to the increased replication of SVCV. It was also found that FTR33 interacted with melanoma differentiation associated gene 5 (MDA5) or mitochondrial anti-viral signaling protein (MAVS) to weaken the promoter activity of type I IFN. It is thus concluded that the FTR33, as an ISG, in zebrafish can negatively regulate IFN-mediated antiviral response.

Gastroprotective 2-(2-phenylethyl)chromone-sesquiterpene hybrids from the resinous wood of Aquilaria sinensis (Lour.) Gilg.

Six previously unprecedented 2-(2-phenylethyl)chromone-sesquiterpene hybrids, aquisinenins A-F (1 - 6), were isolated from the resinous wood of Aquilaria sinensis by a LC-MS-guided fractionation procedure. Their structures were determined by extensive spectroscopic analysis (1D and 2D NMR, UV, IR, and HRMS) and experimental and computed ECD data. Compounds 1 - 6 were rare dimeric 2-(2-phenylethyl)chromone-sesquiterpene derivatives featuring 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone hybridized with different sesquiterpene (eudesmane/guaiane type) moieties via ester bond. Furthermore, all the isolated compounds were evaluated for their protective effects on taurocholic acid (TCA)-induced GES-1 cell injury. The most effective aquisinenin F (6) was used to elucidate the involved mechanism on protection against TCA-induced gastric mucosal damage. Our results indicated that 6 protected against gastric mucosal cell insult by downregulation of the ER stress triggered by TCA.

Anti-inflammatory flavonoid derivatives from the heartwood of Dalbergia odorifera T. Chen.

Two pairs of flavonoid enantiomers (1a/1b and 2a/2b) together with three known analogues (3-5) were isolated from the heartwood of Dalbergia odorifera T. Chen. Their structures were elucidated by extensive spectroscopic analysis (1 D and 2 D NMR, UV, IR, and HRMS) and experimental and calculated ECD data. Compound 2 features an unusual 2-methyl-3(2H)-furanone moiety forming the C-ring of flavonoid, and its putative biosynthetic pathway is also proposed. Compounds 3‒5 exhibited significant inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells with IC50 values of 14.7 ± 0.3 µM, 40.2 ± 1.1 µM, and 3.2 ± 0.1 µM, respectively.

Overexpression of CLEC5A inhibits cell proliferation and metastasis and reverses epithelial-mesenchymal transition in hepatocellular carcinoma / 南方医科大学学报

OBJECTIVE@#To evaluate the effects of CLEC5A expression level on cell proliferation, migration and invasion and epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) and explore the role of CLEC5A in the tumorigenesis and progression of HCC.@*METHODS@#The expression level of CLEC5A was detected in 50 pairs of HCC and adjacent tissues using immunohistochemical staining, and its association with clinicopathological parameters of HCC patients was analyzed. Cultured HCC cell line SK-HEP-1 was transfected with a lentiviral vector overexpressing CLEC5A, and the transfection efficiency was verified using real-time fluorescence quantitative PCR and Western blotting. The changes in proliferation, migration and invasion abilities of the transfected cells were analyzed using CCK-8, 5-ethynyl-29-deoxyuridine (EdU) and Transwell assays, and EMT of the cells was determined using Western blotting.@*RESULTS@#The protein expression level of CLEC5A was significantly lower in HCC tissues than in the adjacent tissues (P < 0.001). The expression level of CLEC5A was significantly correlated with tumor size (P=0.008), tumor number (P=0.010), histological differentiation (P=0.016), microvascular invasion (P=0.024) and BCLC stage (P=0.040). In SK-HEP-1 cells, overexpression of CLEC5A obviously inhibited the cell proliferation, migration and invasion and reversed EMT phenotype of the cells.@*CONCLUSION@#CLEC5A is a potential HCC suppressor gene and may serve as a promising therapeutic target for HCC.

Identification and functional characterization of CL-11 in black rockfish (Sebastes schlegelii).

CL-11 (Collectin-11, also known as Collectin kidney-1 or CL-K1) is a member of collectin family that works as a pattern recognition molecule (PRM) and participating in lectin-complement pathway in host defense against pathogens. We identified the CL-11 homologue SsCL-11 in black rockfish (Sebastes schlegelii) and investigated the functional characteristics in this study. The SsCL-11 has conserved protein modules, i.e. an N-terminal hydrophobic region, a collagen-like region, an α-helical neck region and a carbohydrate recognition domain (CRD). SsCL-11 has varying degrees of expressions in difference tissues, among which the highest expression is observed in liver. It also shows induced expressions in immune-related tissues following Aeromonas salmonicida (A. salmonicida) infection. In addition, SsCL-11 exhibits binding abilities to different kinds of carbohydrates, pathogen-associated molecular patterns (PAMPs) and bacteria. It exhibits comparatively strong binding to l-fucose, d-mannose, and d-glucose, which is consistent with the functional EPN motif in its CRD. SsCL-11 also shows agglutinating effects on various bacteria in the presence of Ca2+. Furthermore, SsCL-11 is confirmed to be a secretory lectin and can form multimers. These findings collectively demonstrate that SsCL-11 can function as a recognition molecule in pathogen resistance in black rockfish, which will promote our understanding of immunological roles of fish collectins.

Cytotoxic sesquiterpenoid dimers from the resin of Commiphora myrrha Engl.

Seven undescribed sesquiterpenoid dimers, commiphomyrones A - G, together with three known analogs, were isolated from the resin of Commiphora myrrha Engl.. The structures of the undescribed compounds were elucidated based on a comprehensive analysis of spectroscopic data (NMR, UV, IR, and MS), and the absolute configurations were defined by comparing the experimental and calculated ECD spectra as well as by performing X-ray crystallographic analysis. All the isolated dimeric sesquiterpenoids feature a 7-oxabicyclo [2.2.1] hept-2-ene moiety formed by the [4 + 2] cycloaddition of two sesquiterpenoids. Commiphomyrones C and G and commiphoratone D showed cytotoxic activity against the HGC-27 cell line with IC50 values of 22.76, 25.01, and 27.51 µM, respectively.

[Sesquiterpenoids from Aquilariae Lignum Resinatum].

Eight sesquiterpenoids were isolated from petroleum ether extract of Aquilariae Lignum Resinatum by various column chromatography techniques including silica gel, ODS, and semi-preparative HPLC. Their structures were identified on the basis of physicochemical properties, UV, IR, MS, and NMR spectroscopic data as(4S,5S,7R,10S)-5,7-dihydroxy-11-en-eudesmane(1),(7R,10S)-eudesma-4-en-11,15-diol(2),(2R,4S,5R,7R)-2-hydroxyeremophila-9,11-dien-8-one(3), 7α-H-9(10)-ene-11,12-epoxy-8-oxoeremophilane(4),(+)-9ß,10ß-epoxyeremophila-11(13)-en(5), 4(14)-eudesmene-8α,11-diol(6), 12,15-dioxo-selina-4,11-dien(7), and 2ß,8 aα-dihydroxy-11-en-eremophilane(8). Compounds 1 and 2 are new compounds, and their absolute configurations were determined by calculating ECD. Compounds 1, 4, and 6-8 could significantly improve taurocholic acid(TCA)-induced gastric mucosal GES-1 cell injury at a concentration of 20 µmol·L~(-1), and the cell protection rates were 23.51%±2.79%, 16.10%±1.25%, 24.45%±4.89%, 17.48%±2.93%, and 21.44%±2.39%, respectively.

Mesoporous Carbon-Supported Pd Nanoparticles in the Metallic State-Catalyzed Acylation of Amides with Aryl Esters via C-O Activation.

Carbon, an abundant, inexpensive, and nonmetallic material, is an inimitable support in heterogeneous catalysis, and variable carbonaceous materials have been utilized to support metal nanoparticle catalysts. We developed an efficient and stable heterogeneous catalyst with highly dispersed metallic palladium nanoparticles embedded in an ordered pore channel of mesoporous carbon and first applied the catalyst to construct imides from amides using aryl esters as an acylation reagent via C-O activation. The catalyst represents excellent catalytic performance and could be reused and recycled five times without any significant decrease in activity. The heterogeneous nature of metallic state palladium was proven to be the active center in the acylation reaction.

Molecular characterization, antibacterial activity and mechanism analyzation of three different piscidins from black rockfish, Sebastes schlegelii.

Sebastes schlegelii (black rockfish) is a popular and economically important fish species in aquaculture. However, disease outbreaks have hindered the development of its cultivation. Antimicrobial peptides (AMPs) are a group of important components in fish innate immune system, that are active in the first line of defense against pathogens. The piscidin family, which are a group of fish-specific AMPs, have been isolated in a part of teleost but still poorly understood in S. schlegelii. In this study, three piscidin genes (Ss-piscidin1, 2, 3) are identified in S. schlegelii and their antibacterial activities and related mechanisms are analyzed. Three Ss-piscidins have conserved signal peptides but highly variable mature peptides and prodomains, and their mature regions all have predicted amphipathic and α-helical structures. Phylogenetic analysis shows that three Ss-piscidins cluster with different fish piscidin sequences into three sister clades, which correspond to three groups of fish piscidin family, respectively. Ss-piscidins have constitutive expressions in different tissues of healthy fish and enhanced expressions after Aeromonas salmonicida challenge. All three piscidins exhibit antibacterial activities, and are able to enhance bacterial membrane permeability and change bacterial morphology to different degrees, with a positive correlation observed among these activities. This suggests that three peptides exert their antibacterial activity through a "membrane-attack" mechanism. Moreover, hemolytic activities of three piscidins are also analyzed, and Ss-piscidin1, with low hemolytic ability and high antibacterial activity, is considered to be a possible candidate template for design of AMP drugs. Results in this study can promote a better understanding of immune responses in black rockfish and facilitate the future development of strategies in fish disease control in aquaculture.

[Quality standard of Lobeliae Chinensis Herba].

In light of related methods in Chinese Pharmacopoeia(2020 edition), this study established the quality standard for Lobeliae Chinensis Herba. The TLC identification method was established with silica gel GF_(254) thin layer plate, diosmin standard, linarin standard, and the reference material of Lobeliae Chinensis Herba. The loss on drying, total ash, acid-insoluble ash, and ethanol-soluble extracts of 18 batches of Lobeliae Chinensis Herba samples were determined according to the general principles in Chinese Pharmacopoeia. Then, HPLC was adopted in the establishment of characteristic chromatogram and content determination. The results showed that the established method can achieve good separation for diosmin, linarin, and lobetyolin. Based on the results of detection for 18 batches of Lobeliae Chinensis Herba samples, the draft quality standard was established, which was expected to provide reference for the revision of this medicinal herb in Chinese Pharmacopoeia.

Trewioidesine A, an unsaturated fatty acid from rhizomes of Alchornea trewioides, shows synergy with NGF in inducing differentiation of pheochromocytoma PC12 cells.

A new unsaturated fatty acid trewioidesine A (1), together with seven known compounds (2 - 8) were isolated from the rhizomes of Alchornea trewioides (Benth.) Muell. Arg. Their structures were established on the basis of extensive spectroscopic data interpretation (1 D and 2 D NMR, and HRESIMS). The absolute configuration of 1 was determined by electronic circular dichroism (ECD) calculations, confirming as trewioidesine A. The functionality of isolated compounds was tested in cultured PC12 cells, a cell line from rat pheochromocytoma. Trewioidesine A was the one showing robust activity in inducing neuronal differentiation: the induction was synergized when co-applied with nerve growth factor (NGF). In addition, a neurofilament 200 (NF200) promoter-luciferase (pNF200-Luc) reporter was used to evaluate the differentiating ability in the transfected PC12 cells for the isolated compounds. Trewioidesine A exhibited a strong NF200 promoter activation, and application of trewioidesine A with low dose of NGF significantly induced the promoter activity over 50%.

Trimeric chalchonoids from the total phenolic extract of Chinese dragon's blood (the red resin of Dracaena cochinchinensis).

Four new chalchonoid trimers, named cochinchinenins N-Q (1-4), along with a pair of known enantiomers (5-6), were isolated from the total phenolic extract of Chinese dragon's blood (the red resin of Dracaena cochinchinensis). The planar structures of 1-4 were elucidated by extensive spectroscopic analysis including HRESIMS and 1D/2D NMR. The absolute configurations of new compounds were established by ECD data. Compound 1 exhibited significant inhibition of nitric oxide production in lipopolysaccharide-stimulated BV-2 microglial cells with IC50 value of 11.5 ± 1.7 µM.

[Research on in vivo metabolites of Longxue Tongluo Capsules by liquid chromatography coupled with hybrid ion trap/time-of-flight mass spectrometry].

Longxue Tongluo Capsules(LTC) has good efficacy against blood stasis syndrome during the recovery period of ischemic stroke. Its main active ingredient is the phenolic extract of Chinese dragon's blood. In our previous study, the primary mass fragmentation pathways of phenolic derivatives from LTC were clarified. Herein, the metabolites in rat plasma were characterized following the oral administration of loureirin A and loureirin C using liquid chromatography coupled with hybrid ion trap/time-of-flight mass spectro-metry(LC-IT-TOF-MS), with 18 and 55 metabolites identified, respectively. On this basis, with the help of the obtained accurate molecular weight, characteristic fragment ions, reference comparison, combined with LTC database and natural products database self-created in our group, 18 prototypes and 106 metabolites were tentatively identified in rat plasma after oral gavage of LTC at a dose of 500 mg·kg~(-1). Glucuronidation, sulfonation, and methylation were major biotransformation pathways of LTC. This study preliminarily clarified the LTC constituents absorbed into blood and laid the foundation for clarifying the effective substances of LTC.