Anti-proliferative and pro-apoptotic effects of tectorigenin on hepatic stellate cells

AIM: To investigate the effect of tectorigenin on proliferation and apoptosis of hepatic stellate cells (HSC)-T6 cells. METHODS: HSC-T6 cells were incubated with tectorigenin at different concentrations, and their proliferation was assessed by bromodeoxyuridine incorporation assay. Apoptosis was detected by flow cytometry assay with Hoechst 33342 staining. Also, generation of reactive oxygen species (ROS), intracellular [Ca2+]i, potential of mitochondrial membrane, activities of cytochrome c and caspase-9 and-3 were investigated to explore a conceivable apoptotic pathway. RESULTS: Tectorigenin suppressed the proliferation of HSC-T6 cells and induced apoptosis of HSC-T6 cells in a time-and dose-dependent manner. Tectorigenin at the concentration of 100 μg/mL greatly inhibited the viability of HSC-T6 cells and induced the condensation of chromatin and fragmentation of nuclei. When treated for 48 h, the percentage of cell growth and apoptosis reached 46.3% ± 2.37% (P = 0.004) and 50.67% ± 3.24% (P = 0.003), respectively. Furthermore, tectorigenin-induced apoptosis of HSC-T6 cells was associated with the generation of ROS, increased intracellular [Ca2+]i, loss of mitochondrial membrane potential, translocation of cytochrome c, and activation of caspase-9 and -3. CONCLUSION: Tectorigenin inhibits proliferation of HSC-T6 cells and induces apoptosis of HSC-T6 cells.

Crystal Structure and Inhibitory Activity against Xanthine Oxidase of Bis(μ_2-chloro)-chloro-(μ-N,N'-(2-pyridylmethylene) Furanmethanoamine Copper(II) Complex

A chloro-bridged dinuclear copper（H） complex with ligand 2-pyridylme-thylene- furfurylamine has been synthesized and characterized by single-crystal X-ray diffraction, and its inhibitory activity on xanthine oxidase （XO） was also evaluated. It crystallizes in the triclinic system, space group P 1 with a = 8.0441（16）, b = 8.5663（17）, c = 10.060（2）A, α = 77.52（3）, β = 72.04（3）, γ = 70.12（3）°, V = 615.3（2）A^3, Z = 1, Dc = 1.731 g/cm^3, F（000） = 322, the final R = 0.0401 and wR = 0.0934 for 1971 observed reflections with I 〉 2σ（I）. X-ray analysis reveals that the Cu（II） cation is five-coordinated by two N atoms of Schiff base and three Cl anions. The C-H…Cl intermolecular and intramolecular hydrogen bonds connect the molecules to form a three-dimensional network. This copper（II） complex shows more potent inhibitory activity against XO with IC50 = 3.48μM than the standard inhibitor allopurinol.

Synthesis, Crystal Structure and Antiproliferative Activity of 2,2-Dimethyl-4-oxochroman-3-ylmorpholine-4-carbodithioate

The crystal structure of the new title compound 2,2-dimethyl-4-oxochroman-3-ylmorpholine-4-carbodithioate（C16H19NO3S2,Mr = 337.44） has been prepared and determined by single-crystal X-ray diffraction.The crystal is of triclinic,space group P1 with a = 9.5518（7）,b = 9.7172（7）,c = 11.0220（8）,α = 67.08（1）,β = 74.66（1）,= 61.31（1）°,V = 822.72（10）3,Z = 2,Dc = 1.362 g/cm3,F（000） = 356,μ = 0.092 mm-1,MoKa radiation（λ = 0.71073）,R = 0.0515 and wR = 0.1389 for 2623 observed reflections with I 2（I）.X-ray diffraction analysis reveals that the chroman ring adopts a half-chair conformation while the morpholine ring shows a chair conformation.Intramolecular and intermolecular C–H···S and C–H···O hydrogen bonds together with π-π interations are found in the structure.The result of MTT assay shows the title compound displays good antiproliferative activity against two human cancer cell lines.

Synthesis and Crystal Structure of Metronidazole-derived Compound

A MET-OH derivative, MET-OTs 1, was designed, prepared and structurally characterized by single-crystal X-ray diffraction. X-ray structure analysis reveals that 1 crystallizes in the monoelinic system, space group P21/c, with a = 16.1178（14）, b = 7.5473（6）, c = 13.4161（11）A, V= 1520.3（2）A3,β=111.3210（10）°, Z= 4, Dc =1.421 g/cm^3 and F（000） = 680.

A New Antimicrobial Flavonol Glycoside from Alchornea davidii

A new flavonol glycoside, isorhamnetin-3-O-b-D-xyloside, was isolated from the extract of leaves and twigs of Alchornea davidii (Euphorbiaceae). Its structure was established on the basis of the spectral analysis and chemical degradation. Antimicrobial assay showed that it moderately inhibited the growth of test bacteria (Staphylococcus aureus, Bacillus subtilis and Pseudomonas fluorescens) and fungi (Candida albicans, Aspergillus niger and Trichophyton rubrum) with MICs at 50 g/mL.

Isochromophilones from an endophytic fungus Diaporthe sp.

Three new azaphilone compounds,isochromophilones X-XII(1-3),together with two known ones sclerotioramine(4)and isochromophilone VI(5)were isolated from the cultures of an endophytic fungus Diaporthe sp.The structures were elucidated by extensive HRESIMS and NMR spectroscopic analyses.All compounds were tested for their cytotoxicities against five human cancer cell lines by MTT method,among which compound 1 showed moderate inhibitory effects on these cell lines.This was the first report of azaphilones isolated from Diaporthe sp.

Carbonic anhydrase-like enzymes in the formation of Lycopodium alkaloid

Plant alkaloids,renowned for their structural diversity and bioactivity,are prominent in both modern and traditional medicine[1].Unraveling the intricacies of plant alkaloid biosynthesis could pave the way for the discovery of new natural products and pathways.It may also shed light on the roles of existing pathways in host biology and provide valuable tools for metabolic engineering in plants and microbes[2].Unlike other major classes of plant natural products,such as terpenoids and polyketides,the formation of alkaloid scaffolds does not conform to a uniform chemical theme or depend on a singular enzyme class[3].A case in point is the Lycopodium alkaloids in the Lycopodiaceae family,where the enzymes responsible for their core scaffold construction remain unidentified[4].

Anti-hyperuricemic and anti-inflammatory actions of vaticaffinol isolated from Dipterocarpus alatus in hyperuricemic mice

The present study was designed to examine the anti-hyperuricemic and anti-inflammatory effects and possible mechanisms of vaticaffinol, a resveratrol tetramer isolated from ethanol extracts of Dipterocarpus alatus, in oxonate-induced hyperuricemic mice. At 1 h after 250 mg·kg^(-1) potassium oxonate was given, vaticaffinol at 20, 40, and 60 mg·kg^(-1) was intragastrically administered to hyperuricemic mice once daily for seven consecutive days. Vaticaffinol significantly decreased serum uric acid levels and improved kidney function in hyperuricemic mice. It inhibited hepatic activity of xanthine dehydrogenase(XDH) and xanthine oxidase(XOD), regulated renal m RNA and protein levels of urate transporter 1(URAT1), glucose transporter 9(GLUT9), organic anion transporter 1(OAT1), organic cation transporter 1(OCT1), OCT2, organic cation/carnitine transporter 1(OCTN1), and OCTN2 in hyperuricemic mice. Moreover, vaticaffinol markedly down-regulated renal protein levels of NOD-like receptor 3(NLRP3), apoptosis-associated speck-like(ASC), and Caspase-1, resulting in the reduction of interleukin(IL)-1β, IL-18, IL-6 and tumor necrosis factor-α(TNF-α) levels in this animal model. Additionally, HPLC and LC-MS analyses clearly testified the presence of vaticaffinol in the crude extract. These results suggest that vaticaffinol may be useful for the prevention and treatment of hyperuricemia with kidney inflammation.

Bioactive Alkaloids from Indole-3-carbinol Exposed Culture of Daldinia eschscholzii

Two new and rare bioactive indoles named dalesindoloids A （1） and B （3）, along with 3-（1H-indole-3ylmethyl）-2-oxindole （2）, were characterized from the indole-3-carbinot （13C）-exposed culture of Daldinia eschscholzii. The absolute configuration of 2 was determined by quantum chemical calculations of the electronic circular dichroism （ECD） spectrum. Dalesindoloids A and B were cytotoxic against the leukemia HL-60 cell line with the IC50 values of 1.0 and 7.4 μmol/L, respectively, with the former being inhibitory on Staphylococcus aureus （MIC： 9.1 μmol/L）. The simultaneous characterization of the alkaloids from the 13C-exposed fungal culture highlighted that the 2,3-epoxyindoline motif can be transformed into both lactam and indolin-3-one moieties. This is the first-time description of the 2,3-epoxyindoline chemical versatility and Wagner-Meerwein rearrangement （WMR） reaction in the microbial culture.

Verticase:a Fibrinolytic Enzyme Produced by Verticillium sp,Tj33,an Endophyte of Trachelospermum jasminoides

Plant endophytes are among the most important resources of biologically active metabolites. Twenty-three endophyte strains residing in Trachelospermum jasminoides were cultivated in vitro with the cultures assayed for the fibrinolytic substance production. As a result, the culture of VerticUlium sp. Tj33 was shown to be the most active. A fibrinolytic enzyme designated as verticase was subsequently purified from the supernatant of Verticillium sp. culture broth by a combination of DEAE-52, Sephadex G-75 and hydrophobic column chromatographies. Verticase, with its molecular mass of 31 kDa and pl of 8.5, was demonstrated to be homogeneous by sodium dodecyl suIfate-polyacrylamide gel electrophoresis and isoelectric focusing electrophoresis. Verticase is an enzyme that hydrolyzes fibrin directly without activation of plaminogen. It was stable in a broad pH range from 4 through to 11 with the optimal reaction pH value and temperature shown to be around 9-10 and 50-60℃, respectively. The fibrinolytic activity of verticase was severely inhibited by phenylmethylsulfony fluoride, indicating that verticase was a serine protease.

Chemistry and biology of Pestalotiopsis-derived natural products

Species within the fungal genus Pestalotiopsis have become a topic of research in many microbial-chemical and pharmacological laboratories because they contain structurally complex,biologically active metabolites.This article is a follow-up to a previous review(Xu,Ebada,and Proksch,Fungal Divers 44:15–31,2010).It focuses particularly on new findings concerning the chemistry and bioactivity of Pestalotiopsis sp.,covering a period ranging from August 2010 to August 2013.Some 160 metabolites were isolated from Pestalotiopsis species during this period and their structures are reported within a biogenetic context.Bioassays showed antitumor,antifungal,and antimicrobial activities to be the most notable bioactivities of secondary metabolites isolated from this genus.The biogenetic pathways associated with the alkaloids,sesquiterpenes,quinines,xanthones,and lactones covered in this review are highlighted.

Study on the secondary metabolites of grasshopper-derived fungi Arthrinium sp.NF2410

Two new 2-carboxymethyl-3-hexyl-maleic anhydride derivatives,arthrianhydride A(1)and B(2),along with three known compounds 3-5,were isolated from the fermentation broth of a grasshopper-associated fungus Arthrinium sp.NF2410.The structures of new compounds 1 and 2 were determined based on the analysis of the HR-ESI-MS and NMR spectroscopic data.Furthermore,compounds 1 and 2 were evaluated on inhibitory activity against the enzyme SHP2 and both of them showed moderate inhibitory activity against SHP2.

Discovery of daspyromycins A and B,2-aminovinyl-cysteine containing lanthipeptides,through a genomics-based approach

Lanthipeptides are one of the largest groups of ribosomally synthesized and post-translationally modified peptides(RiPPs)and are characterized by the presence of lanthionine(Lan)or methyllanthionine residues(MeLan).Only very few lanthipeptides contain a C-terminal 2-aminovinyl-cysteine(AviCys)motif,but all of them show potent antibacterial activities.Recent advances of genome sequencing led to the rapid accumulation of new biosynthetic gene clusters(BGCs)for lanthipeptides.In this study,through our genome mining strategy,we found the AviCys containing lanthipeptides are widespread in the bacterial kingdom.A lanthipeptide-type biosynthetic gene cluster was identified from public bacterial genome database.Two new lanthipeptides,daspyromycins A and B(1 and 2)containing AviCys motif,along with two degraded products,daspyromycins C and D(3 and 4),were obtained after heterologous expression of the gene cluster in Streptomyces albus J1074.Daspyromycins A and B showed potent antimicrobial activity against a spectrum of Gram-positive and-negative bacteria including methicillin-resistant Staphylococcus aureus(MRSA)and vancomycin-resistant Enterococci(VRE).

Synthesis and Biological Activity of Flavane Derivatives

An efficient and feasible synthetic approach was developed for the synthesis of an array of new flavane derivafives from the substituted benzaldehyde with the reduction of chalcones and subsequent cyclization as the key steps. The purity and structure of the products were confirmed by the elemental analysis and a combination of its IR, ^1H and ^13C NMR, and mass spectra. These synthetic compounds were tested for xanthine oxidase （XO） inhibitions and antifungal actions against Candida albicans, Cryptococcus neoformans, Aspergillus sp. and Trichophyton rubrum. 7-Hydrazinocarbonylmethoxy-4＇-methoxyflavane （9） was found to be the most XO inhibitory with IC50=76.4 μmol/L, and the most potent antifungal compound was 4＇-hydrazinocarbonylmethoxyflavane （12） with minimal inhibition concentration MIC=8 μg/mL against Trichophyton rubrum.

Carbon-nitrogen bond formation to construct novel polyketide-indole hybrids from the indole-3-carbinol exposed culture of Daldinia eschscholzii

A plenty of cytochrome P450s have been annotated in the Daldinia eschosholzii genome.Inspired by the fact that some P450s have been reported to catalyze the carbon-nitrogen(C-N)bond formation,we were curious about whether hybrids through C-N bond formation could be generated in the indole-3-carbinol(I3C)exposed culture of D.eschscholzii.As expected,two skeletally undescribed polyketide-indole hybrids,designated as indolpolyketone A and B(1 and 2),were isolated and assigned to be constructed through C-N bond formation.Their structures were elucidated by 1D and 2D NMR spectra.The absolute configurations of 1 and 2 were determined by comparing the recorded and calculated electronic circular dichroism(ECD)spectra.Furthermore,the plausible biosynthetic pathways for 1 and 2 were proposed.Compounds 1 and 2 exhibited significant antiviral activity against H1N1 with IC_(50) values of 45.2 and 31.4μM,respectively.In brief,compounds 1 and 2 were reported here for the first time and were the first example of polyketide-indole hybrids pieced together through C-N bond formation in the I3C-exposed culture of D.eschscholzii.Therefore,this study expands the knowledge about the chemical production of D.eschscholzii through precursor-directed biosynthesis(PDB).

Disulfide bridge-targeted metabolome mining unravels an antiparkinsonian peptide

Peptides are a particular molecule class with inherent attributes of some small-molecule drugs and macromolecular biologics,thereby inspiring continuous searches for peptides with therapeutic and/or agrochemical potentials.However,the success rate is decreasing,presumably because many interesting but less-abundant peptides are so scarce or labile that they are likely‘overlooked’during the characterization effort.Here,we present the biochemical characterization and druggability improvement of an unprecedented minor fungal RiPP(ribosomally synthesized and post-translationally modified peptide),named acalitide,by taking the relevant advantages of metabolomics approach and disulfide-bridged substructure which is more frequently imprinted in the marketed peptide drug molecules.Acalitide is biosynthetically unique in the macrotricyclization via two disulfide bridges and a protease(AcaB)-catalyzed lactamization of AcaA,an unprecedented precursor peptide.Such a biosynthetic logic was successfully re-edited for its sample supply renewal to facilitate the identification of the in vitro and in vivo antiparkinsonian efficacy of acalitide which was further confirmed safe and rendered brain-targetable by the liposome encapsulation strategy.Taken together,the work updates the mining strategy and biosynthetic complexity of RiPPs to unravel an antiparkinsonian drug candidate valuable for combating Parkinson’s disease that is globally prevailing in an alarming manner.

Acatulides A-G,neuroprotective macrolides from Acaulium album H-JQSF

Fungal symbionts co-evolve with hosts and microbial co-inhabitants to acquire an unpredictable potential for producing novel bioactive metabolites,but the knowledge about the topic remains patchy and superficial.Here we present the chemical characterization of acatulides A-G(1-7)as architecturally unprecedented macrolides from the solid-state culture of Acaulium album H-JQSF,an arthropod-associated fungus.The acatulide structures were elucidated by spectroscopic analysis,modified Mosher's method and single-crystal X-ray diffraction.The plausible biosynthetic pathways for compounds 1-4 are proposed.Interestingly,acatulides B-D(2-4)and G(7)were demonstrated to be neuroprotective against the 1-methyl-4-phenylpyridinium(MPP+)-induced damage to SH-SY5Y cells and nematode Caenorhabditis elegans(C.elegans).

解密baccatin Ⅲ生物合成途径,奠定紫衫烷可持续获取途径

The characterization and reconstitution of Taxus enzymes leading to taxoids (diterpenoids with the taxane skeleton seen in the taxol molecule)[1–5] are exciting and may tempt researchers to update the episode about taxol that has been, and will be, prescribed to combat diverse cancers.

Nitric Oxide Potentiates Oligosaccharide-induced Artemisinin Production in Artemisia annua Hairy Roots

The purpose of the present study was to characterize the generation of nitric oxide （NO） in Artemisia annua roots induced by an oligosaccharide elicitor （OE） from Fusarium oxysporum mycelium and the potentiation role of NO in the elicitation of artemisinin accumulation. The OE （0.3 mg total sugar/mL） induced a rapid production of NO in cultures, which exhibited a biphasic time course, reaching the first plateau within 1.5 h and the second within 8 h of OE treatment. Artemisinin content in 20-day-old hairy roots was increased from 0.7mg/g dry wt to 1.3 mg/g dry wt by using the OE treatment for 4d. In the absence of OE, the NO donor sodium nitroprusside （SNP） at 10, 50 ~1 and 100 ~1 enhanced the growth of hairy roots, but had no effect on artemisinin synthesis, The combination of SNP with OE increased artemisinin content from 1.2 mg/g drywt to 2.2 mg/g dry wt, whereas the maximum production of artemisinin in cultures was 28.5 mg/L, a twofold increase over the OE treatment alone. The effects of SNP on the OE-induced artemisinin were suppressed strongly by the NO scavenger 2-（4- carboxyphenyl）-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide （cPTIO）. The results suggest that NO can strongly potentiate elicitor-induced artemisinin synthesis in A. annua hairy roots.

An acidic polysaccharide with xylose branches from Porphyra yezoensis

An acidic polysaccharide (PY3) was isolated from the hot water extract of the red algae Porphyra yezoensis by successive column chromatographies over DEAE-cellulose and Sephadex G-200. PY3 with an average molecular weight of 1.8×105 was demonstrated to be composed of galactose (Gal), 3,6-anhydrogalactose (3,6-AnGal), 6-OSO3-galactose (6-OSO3-Gal) and xylose (Xyl) in an approximate molar ratio of 25:15:10:1. In view of Smith degradation and me-thylation and on the basis of spectral evidence including those of IR, GC, GC-MS, and 1H and 13C NMR, the most probable repeating unit of PY3 could be proposed as [(1-3)β-D-Gal(1- 4)α-L-3,6-AnGal]3-[1-3)β-D-Gal(1-4)α-L-6-OSO3-Gal]2 with a xylose moiety at the C6 of one of every twenty-five β-D-Gal residues. To our knowledge, PY3 was shown to be the first porphyran possessing occasional xylose branches.