Kaempferide triggers apoptosis and paraptosis in pancreatic tumor cells by modulating the ROS production, SHP-1 expression, and the STAT3 pathway.

Pancreatic cancer is one of the deadliest diseases with a poor prognosis and a five-survival rate. The STAT3 pathway is hyperactivated which contributes to the sustained proliferative signals in pancreatic cancer cells. We have isolated kaempferide (KF), an O-methylated flavonol, from the green propolis of Mimosa tenuiflora and examined its effect on two forms of cell death namely, apoptosis and paraptosis. KF significantly increased the cleavage of caspase-3 and PARP. It also downmodulated the expression of Alix (an intracellular inhibitor of paraptosis) and increased the expression of CHOP and ATF4 (transcription factors that promote paraptosis) indicating that KF promotes apoptosis as well as paraptosis. KF also increased intracellular reactive oxygen species (ROS) suggesting the perturbance of the redox state. N-acetylcysteine reverted the apoptosis- and paraptosis-inducing effects of KF. Some ROS inducers are known to suppress the STAT3 pathway and investigation revealed that KF downmodulates STAT3 and its upstream kinases (JAK1, JAK2, and Src). Additionally, KF also elevated the expression of SHP-1, a tyrosine phosphatase which is involved in the negative modulation of the STAT3 pathway. Knockdown of SHP-1 prevented KF-driven STAT3 inhibition. Altogether, KF has been identified as a promoter of apoptosis and paraptosis in pancreatic cancer cells through the elevation of ROS generation and SHP-1 expression.

Chemical Composition, Mosquito Larvicidal and Antimicrobial Activities, and Molecular Docking Study of Essential Oils of Cinnamomum melastomaceum, Neolitsea buisanensis and Uvaria microcarpa from Vietnam.

The leaf oil compositions of two Lauraceae and one Annonaceae plants cultivated in Vietnam were analysed by GC/MS (gas chromatography-mass spectrometry) analysis. The leaf oil of the first Lauraceae plant Cinnamomum melastomaceum contained 34 identified compounds, in which benzyl benzoate (38.5 %), linalool (19.9 %), (E)-caryophyllene (10.5 %), and α-terpineol (6.9 %) were the major compounds. The leaves of the second Lauraceae plant Neolitsea buisanensis gave an oil with the main compounds (E)-ß-ocimene (24.0 %), benzyl benzoate (15.8 %), bicyclogermacrene (14.9 %), and (E)-caryophyllene (6.3 %). The leaf oil of the Annonaceae plant Uvaria microcarpa consisted of the principal compounds (E)-caryophyllene (18.0 %), bicyclogermacrene (8.1 %), and δ-elemene (6.1 %). Two Lauraceae oil samples exhibited strong mosquito larvicidal activity against Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus with LC50 and LD90 values of less than 50 µg/mL. The Annonaceae oil sample showed strong antimicrobial activity against the fungus Aspergillus niger ATCC 1015 with the MIC (minimum inhibitory concentration) value of 32 µg/mL. In the docking approach, the major compounds (E)-caryophyllene, bicyclogermacrene, and benzyl benzoate interacted with the mosquito odorant-binding protein 3OGN, whereas (E)-caryophyllene, bicyclogermacrene, and δ-elemene also potentially interacted with the 4ZA5 protein of fungus A. niger.

Essential oils of the ginger plants Meistera caudata and Conamomum vietnamense: chemical compositions, antimicrobial, and mosquito larvicidal activities.

The current study describes the chemical identification, antimicrobial, and mosquito larvicidal activities of essential oils from Meistera caudata and Conamomum vietnamense, growing in Vietnam. Essential oils were extracted from the leaves and rhizomes, and characterized by the GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry) analysis. Monoterpenes (33.1-89.2 %) were the main chemical class found in these oils. ß-Pinene (30.8 %) and α-pinene (23.8 %) were two major compounds in M. caudata leaf oil. C. vietnamense leaf and rhizome essential oils were dominated by 1,8-cineole (47.9-62.0 %) and limonene (10.3-16.2 %). With the same MIC (minimum inhibitory concentration) value of 25 µg/mL, C. vietnamense leaf and rhizome essential oils strongly inhibited the growth of Gram-positive bacteria Staphylococcus aureus ATCC 29213 and Bacillus subtilis ATCC 6501, respectively. For 24 and 48-h treatments, C. vietnamense leaf essential oil strongly controlled the growth of mosquito Aedes aegypti with the respective LC50 values of 7.67 and 6.73 µg/mL, and the respective LC90 values of 13.37 and 10.83 µg/mL. In the same manner, C. vietnamense rhizome essential oil also showed strong mosquito larvicidal activity against Aedes albopictus with the LC50 values of 12.37 and 12.00 µg/mL, and the LC90 values of 20.56 and 18.58 µg/mL, respectively. C. vietnamense essential essential oils containing a high amount of 1,8-cineole are generally better than M. caudata essential essential oils in both two biological assays.

Chemical Profile and Biological Activities of Fungal Strains Isolated from Piper nigrum Roots: Experimental and Computational Approaches.

The current report describes the chemical investigation and biological activity of extracts produced by three fungal strains Fusarium oxysporum, Penicillium simplicissimum, and Fusarium proliferatum isolated from the roots of Piper nigrum L. growing in Vietnam. These fungi were namely determined by morphological and DNA analyses. GC/MS identification revealed that the EtOAc extracts of these fungi were associated with the presence of saturated and unsaturated fatty acids. These EtOAc extracts showed cytotoxicity towards cancer cell lines HepG2, inhibited various microbacterial organisms, especially fungus Aspergillus niger and yeast Candida albicans (the MIC values of 50-100 µg/mL). In α-glucosidase inhibitory assay, they induced the IC50 values of 1.00-2.53 µg/mL were better than positive control acarbose (169.80 µg/mL). The EtOAc extract of F. oxysporum also showed strong anti-inflammatory activity against NO production and PGE-2 level. Four major compounds linoleic acid (37.346 %), oleic acid (27.520 %), palmitic acid (25.547 %), and stearic acid (7.030 %) from the EtOAc extract of F. oxysporum were selective in molecular docking study, by which linoleic and oleic acids showed higher binding affinity towards α-glucosidase than palmitic and stearic acids. In subsequent docking assay with inducible nitric oxide synthase (iNOS), palmitic acid, oleic acid and linoleic acid could be moderate inhibitors.

Study on the effect of processing methods on the total polyphenol, 2,3,5,4'-tetrahydroxystilben-2-O-ß-D-glucoside, and physcion contents in Fallopia multiflora Thunb. Haraldson root

Abstract This study investigated the changes in the ingredients in Fallopia multiflora Thunb. Haraldson (FMT) root after processing it with different methods such as soaking, stewing, and steaming or combined methods. The total polyphenol, 2,3,5,4'-tetrahydroxystilben-2-O-ß-D-glucoside (THSG), and physcion contents in FMT products after processing were determined using high-performance liquid chromatography (HPLC) and ultraviolet-visible (UV-VIS) methods. The results demonstrated that the processing method and time significantly affected the contents of polyphenol, THSG, and physcion. The physcion and total polyphenol content increased or decreased during processing depending upon the processing time, while the THSG content gradually decreased with an increase in the processing time. The content of physcion (a substance that can cause liver toxicity) was analysed, and the suitable conditions for processing of the FMT products were determined as initial soaking in rice swill for 24 h and subsequent stewing with black beans and water for 12 h

Bioconversion of Lignocellulosic Materials with the Contribution of a Multifunctional GH78 Glycoside Hydrolase from Xylaria polymorpha to Release Aromatic Fragments and Carbohydrates.

A bifunctional glycoside hydrolase GH78 from the ascomycete Xylaria polymorpha (XpoGH78) possesses catalytic versatility towards both glycosides and esters, which may be advantageous for the efficient degradation of the plant cell-wall complex that contains both diverse sugar residues and esterified structures. The contribution of XpoGH78 to the conversion of lignocellulosic materials without any chemical pretreatment to release the water-soluble aromatic fragments, carbohydrates, and methanol was studied. The disintegrating effect of enzymatic lignocellulose treatment can be significantly improved by using different kinds of hydrolases and phenoloxidases. The considerable changes in low (3 kDa), medium (30 kDa), and high (> 200 kDa) aromatic fragments were observed after the treatment with XpoGH78 alone or with this potent cocktail. Synergistic conversion of rape straw also resulted in a release of 17.3 mg of total carbohydrates (e.g., arabinose, galactose, glucose, mannose, xylose) per gram of substrate after incubating for 72 h. Moreover, the treatment of rape straw with XpoGH78 led to a marginal methanol release of approximately 17 µg/g and improved to 270 µg/g by cooperation with the above accessory enzymes. In the case of beech wood conversion, the combined catalysis by XpoGH78 and laccase caused an effect comparable with that of fungal strain X. polymorpha in woody cultures concerning the liberation of aromatic lignocellulose fragments.

A coumarin derivative-Cu2+ complex-based fluorescent chemosensor for detection of biothiols.

Herein, a novel fluorescent sensor has been developed for the detection of biothiols based on theoretical calculations of the stability constant of the complex between a Cu2+ ion and (E)-3-((2-(benzo[d]thiazol-2-yl)hydrazono)methyl)-7-(diethylamino) coumarin (BDC) as a fluorescent ligand. In this study, on the basis of density functional theory method, the Gibbs free energy of ligand-exchange reaction and the solvation model were carried out using thermodynamic cycles. The obtained results are in good agreement with the experimental data. The BDC-Cu2+ complex can be used as a fluorescent sensor for the detection of biothiols in the presence of non-thiol containing amino acids, with a detection limit for cysteine at 0.3 µM. Moreover, theoretical calculations of excited states were used to elucidate variations in the fluorescence properties. The computed results show that the excited doublet states D2 and D1 are dark doublet states, which quench the fluorescence of the complex.

Aspermicrones A-C, novel dibenzospiroketals from the seaweed-derived endophytic fungus Aspergillus micronesiensis.

Chemical investigation of the Kappaphycus alvarezii-derived endophytic fungus Aspergillus micronesiensis lead to the isolation of three novel dibenzospiroketals, aspermicrones A-C (1-3). Their chemical structures were determined by extensive analysis of HR-ESI-MS and NMR spectral data. The absolute configurations of them were determined by experimental and TD-DFT theoretical calculated circular dichroism spectra. Compound 2 exhibited selective cytotoxic effect toward HepG2 cell line (IC50 = 9.9 µM). Additionally, both of compounds 2 and 3 displayed anti-microbial activity against Staphylococcus aureus (MIC = 123.2 µM for each compound). Compound 1 was inactivity in both cytotoxic and anti-microbial assays.

Voltammetry Determination of Pb(II), Cd(II), and Zn(II) at Bismuth Film Electrode Combined with 8-Hydroxyquinoline as a Complexing Agent.

A novel method was developed for the simultaneous determination of Pb(II), Cd(II), and Zn(II) based on the cathodic stripping response at a bismuth film electrode associated with oxine as a chelating agent. The developed method provided a high and sharp electrochemical response compared with the method without oxine. A linear response of peak currents was observed for Pb(II), Cd(II), and Zn(II) concentration in the range from 2 ppb to 110 ppb. The detection limits of Pb(II), Cd(II), and Zn(II) were 0.45, 0.17, and 0.78 ppb, respectively. This method was successfully applied to the determination of Pb(II), Cd(II), and Zn(II) in lake-water and river-water samples. The metals were detected at the ultratrace level, showing the feasibility of the proposed method for environmental applications.

A new rhodamine-based fluorescent chemodosimeter for mercuric ions in water media.

A new rhodamine-ethylenediamine-nitrothiourea conjugate (RT) was synthesized and its sensing property as a fluorescent chemodosimeter toward metal ions was explored in water media. Analytical results from absorption and fluorescence spectra revealed that the addition of Hg(2+) ions to the aqueous solution of the chemodosimeter RT caused a distinct fluorescence OFF-ON response with a remarkable visual color change from colorless to pink; however, no clear spectral and color changes were observed from other metal ions including: Zn(2+) , Cu(2+) , Cd(2+) , Pb(2+) , Ag(+) , Fe(2+) , Cr(3+) , Co(3+) , Ni(2+) , Ca(2+) , Mg(2+) , K(+) and Na(+) . The sensing results and the molecular structure suggested that a Hg(2+) -induced a desulfurization reaction and cyclic guanylation of the thiourea moiety followed by ring-opening of the rhodamine spirolactam in RT are responsible for a distinct fluorescence turn-on signal, indicating that RT is a remarkably sensitive and selective chemodosimeter for Hg(2+) ions in aqueous solution. Hg(2+) within a concentration range from 0.1 to 25 µM can be determined using RT as a chemodosimeter and a detection limit of 0.04 µM is achieved.

A new fluorescent chemosensor for Hg2+ in aqueous solution.

We prepared an aminothiourea-derived Schiff base (DA) as a fluorescent chemosensor for Hg(2+) ions. Addition of 1 equiv of Hg(2+) ions to the aqueous solution of DA gave rise to an obvious fluorescence enhancement and the subsequent addition of more Hg(2+) induced gradual fluorescence quenching. Other competing ions, including Pb(2+), Cd(2+), Cr(3+), Zn(2+), Fe(2+), Co(3+), Ni(2+), Ca(2+), Mg(2+), K(+) and Na(+) , did not induce any distinct fluorescence changes, indicating that DA can selectively detect Hg(2+) ions in aqueous solution.

Rhodamine-derived Schiff base for the selective determination of mercuric ions in water media.

A new rhodamine-derived Schiff base (RS) was synthesized and its sensing property to metal ions was investigated by UV/vis and fluorescence spectroscopies. Addition of Hg2+ ions to the aqueous solution of RS gave a visual color change as well as significantly fluorescent enhancement, while other ions including Pb2+, Cd2+, Cr3+, Zn2+, Cu2+, Fe2+, Co3+, Ni2+, Ca2+, Mg2+, K+ and Na+ ions did not induce any distinct color/spectral changes, which constituted a Hg2+-selective fluorescent OFF-ON chemosensor. The Hg2+-induced ring-opening of spirolactam of rhodamine in RS resulted in the dual chromo- and fluorogenic observation.