Inhibitory Activity Against Rhizoctonia Solani and Chemical Composition of Extract from Moutan Cortex.

Rice sheath blight (RSB), caused by Rhizoctonia solani, is a significant disease of rice. The negative effects of chemical fungicides have created an urgent need for low-toxicity botanical fungicides. Our previous research revealed that the ethanol crude extract of Moutan Cortex (MC) exhibited superior antifungal activity against R. solani at 1000 µg/mL, resulting in a 100 % inhibition rate. The antifungal properties were mainly found in the petroleum ether extract. However, the active ingredients of the extract are still unclear. In this study, gas chromatography-mass spectrometry (GC-MS) was utilised for the analysis of its chemical components. The mycelium growth rate method was utilized to detect the antifungal activity. The findings indicated that paeonol constituted the primary active component, with a content of more than 96 %. Meanwhile, paeonol was the most significant antifungal active ingredient, the antifungal activity of paeonol (EC50=44.83 µg/mL) was much higher than that of ß-sitosterol and ethyl propionate against R. solani. Observation under an optical microscope revealed that paeonol resulted in abnormal mycelial morphology. This study provided theoretical support for identifying monomer antifungal compounds and developing biological fungicides for R. solani.

Semiochemical signatures associated with differential attraction of Anopheles gambiae to human feet.

BACKGROUND: Several human-produced volatiles have been reported to mediate the host-seeking process under laboratory conditions, yet no effective lure or repellent has been developed for field application. Previously, we found a gradation of the attractiveness of foot odors of different malaria free individuals to Anopheles gambiae sensu stricto Giles. In this study, foot odor of the individual with the most attractive 'smelly' feet to the An. gambiae was collected, analyzed and attractive blend components identified. METHODS: The foot odor of the individual with the most attractive 'smelly' feet to the An. gambiae was trapped on Porapak Q and analyzed by gas chromatography-linked mass spectrometry (GC-MS). Specific constituents perceived by the insect olfactory system were then identified by GC-linked to electro-antennography detector (GC-EAD) and characterized by GC-MS. The contribution of each constituent to the behavioral response of An. gambiae was assessed through subtractive assays under semi-field conditions in a screen-house using Counter Flow Geometry (CFG traps) baited with (i) the blend of all the EAD-active and (ii) other blends containing all components with exclusion of one component at a time. The number of mosquitoes trapped in the baited CFG traps were compared with those in the control traps. RESULTS: Eleven major and minor constituents: 2 carboxylic acids, six aldehydes, two ketones and one phenolic compound, were confirmed to be EAD-active. The contribution of each constituent to the behavioral response of An. gambiae was assessed through subtractive assays under semi- field conditions. Exclusion/ subtraction of one of the following compounds: i-butyric acid, i-valeric acid, n-octanal, n-nonanal, n-decanal, n-dodecanal, undecanal or n-tridecanal, from each blend led to reduction in the attractiveness of all the resulting blends, suggesting that all of them are critical/important for the attractiveness of the foot odor to An. gambiae mosquitoes. However, exclusion/subtraction of 4-ethoxyacetophenone, 4-ethylacetophenone and/or 2-methylphenol, led to significant enhancements in the attractiveness of the resulting blends, suggesting that each of these compounds had repellent effect on An. gambiae ss. Undecanal exhibited kairomonal activity at low natural concentrations under semi-field conditions but repellent activity at high unnatural conditions in the laboratory. Furthermore, the comparison of the mean mosquito catches in traps baited with the nine-component blend without 4-ethoxyacetophenone, 4-ethylacetophenone and the complete foot odor collection revealed that the former is significantly more attractive and confirmed the repellent effect of the two carbonyl compounds at low natural concentration levels. CONCLUSION: These results suggest that differential attractiveness of An. gambiae to human feet is due to qualitative and/or qualitative differences in the chemical compositions of the foot odors from individual human beings and relative proportions of the two chemical signatures (attractants versus repellents) as observed from the ratios of the bioactive components in the foot odors of the most attractive and least attractive individuals. Chemical signature means the ensemble of the compounds released by the organism in a specific physiological state. The chemical signature is emitter-dependent, but does not depend on receiver response. Thus, there is only one chemical signature for one individual or species that may eventually include inactive, attractive and repellent components for another organism. The nine-component attractive blend has a potential as an effective field bait for trapping of malaria vectors in human dwellings.

Lignin-Derived Syringol and Acetosyringone from Palm Bunch Using Heterogeneous Oxidative Depolymerization over Mixed Metal Oxide Catalysts under Microwave Heating.

Biomass valorization to building block chemicals in food and pharmaceutical industries has tremendously gained attention. To produce monophenolic compounds from palm empty fruit bunch (EFB), EFB was subjected to alkaline hydrothermal extraction using NaOH or K2CO3 as a promotor. Subsequently, EFB-derived lignin was subjected to an oxidative depolymerization using Cu(II) and Fe(III) mixed metal oxides catalyst supported on γ-Al2O3 or SiO2 as the catalyst in the presence of hydrogen peroxide. The highest percentage of total phenolic compounds of 63.87 wt% was obtained from microwave-induced oxidative degradation of K2CO3 extracted lignin catalyzed by Cu-Fe/SiO2 catalyst. Main products from the aforementioned condition included 27.29 wt% of 2,4-di-tert-butylphenol, 19.21 wt% of syringol, 9.36 wt% of acetosyringone, 3.69 wt% of acetovanillone, 2.16 wt% of syringaldehyde, and 2.16 wt% of vanillin. Although the total phenolic compound from Cu-Fe/Al2O3 catalyst was lower (49.52 wt%) compared with that from Cu-Fe/SiO2 catalyst (63.87 wt%), Cu-Fe/Al2O3 catalyst provided the greater selectivity of main two value-added products, syringol and acetosyrigone, at 54.64% and 23.65%, respectively (78.29% total selectivity of two products) from the NaOH extracted lignin. The findings suggested a promising method for syringol and acetosyringone production from the oxidative heterogeneous lignin depolymerization under low power intensity microwave heating within a short reaction time of 30 min.

New lignans and acetophenone derivatives with α-glucosidase inhibitory activity from the leaves of Melicope patulinervia.

Four new lignans, patulinones A-D (1-4) and three new acetophenone derivatives, patulinones E-G (5-7) were isolated from the leaves of Melicope patulinervia. Their structures were elucidated on the basis of the interpretation of HR-ESIMS, NMR, CD data. All the isolated compounds were evaluated for α-glucosidase inhibitory activity. Of the isolates, compound 4 was found to exhibit the strongest inhibition against α-glucosidase with IC50 value of 6.02 ± 0.46 µM.

Molecular separation of ibuprofen and 4-isobutylacetophenone using octanol organic solution by porous polymeric membranes.

Molecular separation of pharmaceutical contaminants from water has been recently of great interest to alleviate their detrimental impacts on environment and human well-being. As the novelty, this investigation aims to develop a mechanistic modeling approach and consequently its related CFD-based simulations to evaluate the molecular separation efficiency of ibuprofen (IP) and its metabolite 4-isobutylacetophenone (4-IBAP) from water inside a porous membrane contactor (PMC). For this purpose, octanol has been applied as an organic phase to extract IP and 4-IBAP from the aqueous solution due to high solubility of solutes in octanol. Finite element (FE) technique is used as a promising tool to simultaneously solve continuity and Navier-Stokes equations and their associated boundary conditions in tube, shell and porous membrane compartments of the PMC. The results demonstrated that the application of PMC and liquid-liquid extraction process can be significantly effective due to separating 51 and 54% of inlet IP and 4-IBAP molecules from aqueous solution, respectively. Moreover, the impact of various operational / functional parameters such as packing density, the number of fibrous membrane, the module length, the membrane porosity / tortuosity, and ultimately the aqueous solution flow rate on the molecular separation efficiency of IP and 4-IBAP is studied in more details.

New insights into Paeoniaceae used as medicinal plants in China.

Paeoniaceae is an abundant germplasm resource with significant medicinal values in China, the principal medicinal components of which include paeoniflorin and paeonol. These compounds are typically obtained from air-dried root samples, which the use of freeze-drying as an alternative method has not been tested. Additionally, the presence of these two compounds in various wild Paeoniaceae species has not been previously explored, nor have the differences between various plant organs been fully evaluated. Here, freeze-drying and air-drying methods were compared to assess the changes in paeoniflorin and paeonol in root samples using ultra-performance liquid chromatography-mass spectrometer. The contents of these compounds in the roots, leaves, stems, and petals were then tested in freeze-dried materials. We also quantitatively detected the paeoniflorin and paeonol contents in the roots of 14 species collected from 20 natural habitats. Results indicated that the paeoniflorin content decreased under air-drying in comparison to freeze-drying, while the opposite trend was observed for paeonol. Our findings also demonstrated that the root xylem of species in Section Moutan, particularly Paeonia ostii, contains considerable paeonol and paeoniflorin and should thus be fully utilized as a medicinal resource. Furthermore, paeonol was mainly detected in the roots, while paeoniflorin was widely distributed in different organs; the highest content was in the leaf at the budding stage, suggesting that the leaves should be developed as a new paeoniflorin resource. Paeoniflorin contents were also found to be higher at earlier development stages. Based on the standards of the Chinese Pharmacopoeia, five species of Section Moutan and six species of Section Paeonia could be used as potential traditional Chinese medicinal resources. These findings of this study enhance our understanding of these two medicinal compounds and provide a foundation for the further development and utilization of Paeoniaceae as medicinal plant resources.

Prenylated Acetophloroglucinol Dimers from Acronychia trifoliolata: Structure Elucidation and Total Synthesis.

The isolation of 12 secondary metabolites, including seven new acetophenone monomers, from the 50% CH3OH/CH2Cl2 extract (N089419-L/6) of Acronychia trifoliolata was reported previously. In the present work, three new prenylated acetophenone dimers (1-3) and five known dimers (4-8) were isolated, and their structures were elucidated by using various NMR spectroscopic techniques and HRMS. Among the new dimers, an unprecedented 4-isobutyl-3-isopropyltetrahydro-2H-pyran ring was observed in the structure of 1. This study is the first to report the formation of a 2H-pyran ring between two prenylated acetophloroglucinols. Only four related dimers have been reported before, and they were formylated phloroglucinol dimers from the family Eucalypteae. Compounds 2 and 3 are acrovestone-like dimers, and the structure of 3 was confirmed by total synthesis. The evaluation of the antiproliferative activity of isolated and synthesized acrovestone-like dimers indicated that a double bond in the prenyl-like moiety as found in the more active compounds might be important for mediating activity, while the pendant isobutyl group seems to be less important.

Stainless Steel Wire Mesh Supported Molecularly Imprinted Composite Membranes for Selective Separation of Ebracteolata Compound B from Euphorbia fischeriana.

Stainless steel wire mesh supported molecularly imprinted composite membranes for selective separation of Ebracteolata Compound B (ECB) were prepared based on surface polymerization using ECB separated from Euphorbia fischeriana as a template, acrylamide as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, azodiisobutyronitrile as an initiator, and stainless steel wire mesh as support. Structure and purity of ECB were characterized by nuclear magenetic resonance (¹H-NMR, 13C-NMR) and ultra high performance liquid chromatography (UHPLC). The molecularly imprinted composite membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The membrane adsorbed on the ECB reached equilibrium about 30 min later, with a maximum adsorption amount of 3.39 µmol/cm². Adsorption behavior between ECB and the molecularly imprinted composite membranes followed pseudo-second-order kinetics equation and Freundlich isotherm model. The molecularly imprinted composite membranes that could selectively identify and transport ECB in similar structures have a permeation rate of 38.71% to ECB. The ECB content in the permeation solution derived from the extract of Euphorbia fischeriana through the imprinted membrane was 87%. Overall, the obtained results demonstrated that an efficient approach with the molecularly imprinted composite membranes for selective separation of ECB from Euphorbia fischeriana.

Potential hypoglycemic effect of acetophenones from the root bark of Cynanchum wilfordii.

Three new acetophenones, named cynwilforones A-C (1-3), together with cynandione A (4) were isolated from the root bark of Cynanchum wilfordii (Maxim.) Hemsl. Their structures were deduced based on spectroscopic analysis and chemical methods. Compounds 1 and 4 exhibited potential hypoglycemic effects through inhibition of hepatic gluconeogenesis by down-regulating the expression of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. This is the first report that acetophenones from the root bark of C. wilfordii possesses potential hypoglycemic activity in vitro.

Chemical characterisation of the constituents of Eugenia protenta McVaugh and leishmanicidal activity of dimethylxanthoxylin.

The chemical study of Eugenia protenta McVaugh extracts performed by classical and high-performance liquid chromatography techniques and spectral methods has led to the identification of known triterpenoids, flavonoids and an acetophenone derivative (dimethylxanthoxylin). The effect of dimethylxanthoxylin on Leishmania (Leishmania) amazonensis was evaluated against the promastigotes forms after 96 h of treatment. Dimethylxanthoxylin reduced 57 and 59% of the promastigotes growth when treated with 50 and 100 µg/mL solutions, respectively (IC50 117.35 µg/mL or 52.3 µM). Cytotoxicity experiments using MTT assays showed that this substance did not promote cell death after 24 h of treatment. Dimethylxanthoxylin was active on the promastigotes and could be a promising agent for treating leishmaniasis.

Acetophenone derivatives from the roots of Melicope ptelefolia.

Five new prenylated acetophenones, melicoptelins A-E (1-5), along with one known congener (6) were isolated from the roots of Melicope ptelefolia. Among them, compounds 2a/2b, 3a/3b, and 4a/4b were obtained as inseparable interconverting mixtures of keto and enol tautomers. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D, 2D NMR and HRESIMS. Compouds 2a/2b, 4a/4b and 5 exhibit protein tyrosine phosphatase 1B (PTP1B) inhibitory activity with IC50 values of 34.4, 55.2 and 66.6 µM, respectively.

Isolation and identification of new prenylated acetophenone derivatives from Acronychia oligophlebia.

Three new prenylated acetophenone derivatives, acronyculatin P (1), acronyculatin Q (2), and acronyculatin R (3) were isolated from the leaves of Acronychia oligophlebia. Their structures were identified by extensive analyses of spectroscopic data (IR, UV, ESI-HRMS, 1D and 2D NMR) and comparison with the literatures. In addition, the cytotoxic activity against MCF-7 cells of the compounds were evaluated by the MTT assay and the IC50 values were 56.8, 40.4 and 69.1 µM, respectively.

Characteristic Scent from the Tahitian Liverwort, Cyathodium foetidissimum.

The volatile components of the Tahitian liverwort Cyathodium foetidissimum was analyzed using headspace solid phase micro-extraction (SPME) and GC-MS. Three volatile components, 4-methoxystyrene (24.4%), 3,4-dimethoxystyrene (28.7%), and skatole (15.9%) were identified as the major components from the fresh C. foetidissimum, along with several aliphatic aldehydes, n-octanal, n-nonanal, and n-decanal. However, (E)-2-nonenal recognized as aged malodor was not identified. In GC-O analysis, 2-aminoacetophenone was detected as one of the minor components with a strong aging note. In fact, C. foetidissimum showed the characteristic aging odor reminiscent the damp smell from old chest of drawers, or the civet like note with very strong feces and urine odor. The mixture consisted of 4-methoxystyrene, 3,4-dimethoxystyrene, and skatole in the detected ratio showed the sedative effect on CNV (contingent negative variation) measurement.

New Acetophenone Derivatives from Acronychia oligophlebia and Their Anti-inflammatory and Antioxidant Activities.

Seven new acetophenone derivatives (acroliones A - G, 1 - 7) and three known ones (8 - 10) were isolated from the leaves of Acronychia oligophlebia. Their structures were elucidated based on extensive spectroscopic analyses (IR, UV, HR-ESI-MS, 1D- and 2D-NMR), X-ray diffraction and comparison with literature data. The anti-inflammatory and antioxidant activities of all isolates were evaluated.

Preliminary Quality Evaluation and Characterization of Phenolic Constituents in Cynanchi Wilfordii Radix.

A new phenolic compound, 2-O-ß-laminaribiosyl-4-hydroxyacetophenone (1), was isolated from Cynanchi Wilfordii Radix (CWR, the root of Cynanchum wilfordii Hemsley), along with 10 known aromatic compounds, including cynandione A (2), bungeisides-C (7) and -D (8), p-hydroxyacetophenone (9), 2',5'-dihydroxyacetophenone (10), and 2',4'-dihydroxyacetophenone (11). The structure of the new compound (1) was elucidated using spectroscopic methods and chemical methods. The structure of cynandione A (2), including a linkage mode of the biphenyl parts that remained uncertain, was unambiguously confirmed using the 2D 13C-13C incredible natural abundance double quantum transfer experiment (INADEQUATE) spectrum. Additionally, health issues related to the use of Cynanchi Auriculati Radix (CAR, the root of Cynanchum auriculatum Royle ex Wight) instead of CWR have emerged. Therefore, constituents present in methanolic extracts of commercially available CWRs and CARs were examined using UV-sensitive high-performance liquid chromatography (HPLC), resulting in common detection of three major peaks ascribed to cynandione A (2), p-hydroxyacetophenone (9), and 2',4'-dihydroxyacetophenone (11). Thus, to distinguish between these ingredients, a thin-layer chromatography (TLC) method, combined with only UV irradiation detection, focusing on wilfosides C1N (12) and K1N (13) as marker compounds characteristic of CAR, was performed. Furthermore, we propose this method as a simple and convenient strategy for the preliminary distinction of CWR and CAR to ensure the quality and safety of their crude drugs.

Smelling Pseudomonas aeruginosa infections using a whole-cell biosensor - An alternative for the gold-standard culturing assay.

Improved easy-to-use diagnostic tools for infections are in strong demand worldwide. Yet, despite dramatic advances in diagnostic technologies, the gold-standard remains culturing. Here we offer an alternative tool demonstrating that a bacterial biosensor can efficiently detect Pseudomonas aeruginosa infections in patients suffering from otitis externa. Detection was based on specific binding between the biosensor and 2-aminoacetophenone (2-AA), a volatile produced by P. aeruginosa in high amounts. We collected pus samples from ears of 26 subjects exhibiting symptoms of otitis externa. Detection of P. aeruginosa using the biosensor was compared to detection using gold-standard culturing assay and to gas-chromatograph-mass-spectrometry (GC-MS) analyses of 2-AA. The biosensor strain test matched the culture assay in 24 samples (92%) and the GC-MS analyses in 25 samples (96%). With this result in hand, we designed a device containing a whole-cell luminescent biosensor combined with a photo-multiplier tube. This device allowed detection of 2-AA at levels as low as 2 nmol, on par with detection level of GC-MS. The results of the described study demonstrate that the volatile 2-AA serves as an effective biomarker for P. aeruginosa in ear infections, and that activation of the biosensor strain by 2-AA provides a unique opportunity to design an easy-to-use device that can specifically detect P. aeruginosa infections.

Antioxidant acetophenone glycosides from the roots of Euphorbia ebracteolata Hayata.

A new acetophenone diglycoside, 2,4-dihydroxy-6-methoxy-3-methyl-acetophenone 4-O-gentiobioside (1), along with six know analogues (2-6), were isolated from the roots of Euphorbia ebracteolata. The structures of these isolates were determined by UV, HRESIMS, 1D and 2D NMR spectral analyses. In addition, all acetophenones showed moderate DPPH free radical scavenging capability, and no cytotoxicity against five human cancer cell lines.

Cell Cycle Arrest and Apoptosis Induction of Phloroacetophenone Glycosides and Caffeoylquinic Acid Derivatives in Gastric Adenocarcinoma (AGS) Cells.

INTRODUCTION: In the present study, we analyzed anti-proliferative and apoptosis induction activity of five phenolic compounds: echisoside, pleoside, chlorogenic acid, 4,5-Di-O-caffeoylquinic acid, and cynarin on AGS (adenocarcinoma gastric) cell line. METHOD: These phenolic compounds were isolated from methanol extract of Dorema glabrum root. An MTT assay was conducted to evaluate the inhibitory effect on cancer cells. EB/AO staining was done to assess the mode of cell death and morphological changes of the cells' nuclei. Cell cycle distribution of the cells was analyzed by flow cytometry, and for further confirmation of the pathway, mRNA levels of apoptosis cascade players were quantified by qRT-PCR. RESULT: We found that echisoside, pleoside, chlorogenic acid, 4,5-Di-O-caffeoylquinic acid, and cynarin inhibited the proliferation of AGS cancer cells in vitro. Our data revealed that these compounds triggered morphological changes characteristic of apoptotic cell death. These compounds up-regulated bax and caspase3 expression and down-regulated cyclin D1, bcl2, VEGFA, c-myc and survivin. Moreover, cell population increased at the G1 phase, and a number of cells at the G2/M phase of the cell cycle decreased after treatment. CONCLUSION: All these data suggest that phenolic compounds have a cytotoxic effect on gastric cancer cells and could trigger apoptosis. Besides cytotoxic activity, they could potentially arrest the cell cycle at the G1 phase.

Two new compounds from Nigrospora sphaerica ZMT05, a fungus derivated from Oxya chinensis Thunber.

A new pyrrolidinone derivative named nigrosporamide A (1), and a new acetophenone derivative, 4-prenyloxyclavatol (2), were isolated from an endophytic fungus Nigrospora sphaerica (collection No. ZMT05) isolated from Oxya chinensis Thunberg. Their chemical structures were established on the basis of the interpretation of spectroscopic data. In primary in vitro bioassay, nigrosporamide A (1) exhibited strong antifungal activity against Colletotrichum gloeosporioides and high inhibitory activity towards α-glucosidase.

First report on isolation of 2,3,4-trihydroxy-5-methylacetophenone from palmyra palm (Borassus flabellifer Linn.) syrup, its antioxidant and antimicrobial properties.

The first report on isolation and characterization of 2,3,4-trihydroxy-5-methylacetophenone (1), nicotinamide (2), and uracil (3) from palmyra palm syrup is described. Total phenolic content (TPC) and Total flavonoid content (TFC) of palm syrup were 244.70±5.77(mggallic acid/kg of syrup) and 658.45±27.86(mg quercetin/kg of syrup), respectively. Compound 1 exhibited DPPH radical scavenging activity with an IC50 value of 20.02±0.14µM which was better than ascorbic acid (IC50=22.59±0.30µM). Compound 1 also showed broad spectrum antibacterial activity against Escherichia coli, Mycobacterium smegmatis, Staphylococcus aureus and Staphylococcus simulans.