Ethyl Acetate-soluble Extract Research Articles

Toxicological evaluation of different solvent fractions of Waltheria indica linn. root in male wistar rats

Waltheria indica Linn. root (WILR) is a multipurpose medicinal plant with abundance of phytochemical compounds. The optimal solvents for extraction of a particular bioactive compound depends not only on the yield of the compound but also on the toxic effect of the solvent used. Therefore, this study was designed to evaluate the toxic effects of hexane, dichloromethane and ethyl acetate solvent fractions of WILR in male Wistar rats. Three doses (200, 500, or 1000 μg/kg BW) of hexane, dichlorometh ane and ethyl acetate solvent fractions of WILR were used. Male Wistar rats (n=5) were administered with 200, 500, or 1000 μg/kg of hexane, dichloromethane, and ethyl acetate soluble extracts of WILR, while control received distilled water, daily for 15 days. The rats were thereafter sacrificed, blood samples were collected and serum separated. Haematological serum biochemical parameters were determined according to standard procedure. The result showed non-significant effect on relative organ weight and haematological parameters while the serum ALT was significantly increased by administration of hexane, dichloromethane, and ethyl acetate soluble extracts of WILR. Blood Urea Nitrogen was also increased significantly (p < 0.05) at 200 and 500 μg/kg of hexane and dichloromethane respectively. The ethyl acetate and hexane fraction also caused severe periportal cellular infiltration in the liver while the hexane fraction caused glomerular necrosis. The hexane, dichloromethane and ethyl acetate soluble extracts of (WILR) have adverse effect on the integrity liver and kidney. Hence, these extracts should be used with caution in patient with hepatic and renal impairment.

Toxicological evaluation of different solvent fractions of Waltheria indica linn. root in male wistar rats

Waltheria indica Linn. root (WILR) is a multipurpose medicinal plant with abundance of phytochemical compounds. The optimal solvents for extraction of a particular bioactive compound depends not only on the yield of the compound but also on the toxic effect of the solvent used. Therefore, this study was designed to evaluate the toxic effects of hexane, dichloromethane and ethyl acetate solvent fractions of WILR in male Wistar rats. Three doses (200, 500, or 1000 μg/kg BW) of hexane, dichlorometh ane and ethyl acetate solvent fractions of WILR were used. Male Wistar rats (n=5) were administered with 200, 500, or 1000 μg/kg of hexane, dichloromethane, and ethyl acetate soluble extracts of WILR, while control received distilled water, daily for 15 days. The rats were thereafter sacrificed, blood samples were collected and serum separated. Haematological serum biochemical parameters were determined according to standard procedure. The result showed non-significant effect on relative organ weight and haematological parameters while the serum ALT was significantly increased by administration of hexane, dichloromethane, and ethyl acetate soluble extracts of WILR. Blood Urea Nitrogen was also increased significantly (p < 0.05) at 200 and 500 μg/kg of hexane and dichloromethane respectively. The ethyl acetate and hexane fraction also caused severe periportal cellular infiltration in the liver while the hexane fraction caused glomerular necrosis. The hexane, dichloromethane and ethyl acetate soluble extracts of (WILR) have adverse effect on the integrity liver and kidney. Hence, these extracts should be used with caution in patient with hepatic and renal impairment.

Antimicrobial metabolite of Cordyceps tenuipes targeting MurE ligase and histidine kinase via in silico study

Cordyceps spp. are widely healthy foods around the world with several traditional uses and bio-functionalities. The chemical characterization of ethyl acetate-soluble extract of the entomopathogenic fungus Cordyceps tenuipes NBRC 111,630 afforded two new metabolites with 1,6-dioxaspiro[4.4]nonane motif, tenuipesone A (1) and tenuipesone B (2), along with four well-known metabolites (3-6). The elucidation of the chemical structures was carried out via extensive spectroscopic experiments including FTIR, HRMS, 1D-NMR, and 2D-NMR. Theprobable biosynthetic pathway of 1 and 2 was hypothesized. From the six isolates, beauvericin (6) exhibited antimicrobial activity against Bacillus subtilis and Staphylococcus aureus with respective MIC of 6.25 and 12.5μM. Docking results exhibited that beauvericin (6) has significant binding affinities against MurE and HK proteins with ΔG = - 8.021 and - 8.585kcal/mol, respectively. KEY POINTS: • Six compounds, including two new, were isolated from the entomopathogenic fungus Cordyceps tenuipes. • Plausible biosynthetic pathway of compounds 1, 2, 4, and 5 was hypothesized. • Beauvericin (6) exhibited significant antimicrobial activity against Bacillus subtilis and Staphylococcus aureus alongside binding affinities against MurE and HK proteins in MOE study.

Bioactive Bibenzyl Enantiomers From the Tubers of Bletilla striata.

Six new bibenzyls (three pairs of enantiomers), bletstrins D–F (1–3), were isolated from the ethyl acetate-soluble (EtOAc) extract of tubers of Bletilla striata (Thunb.) Rchb f. Their structures, including absolute configurations, were determined by 1D/2D NMR spectroscopy, optical rotation value, and experimental electronic circular dichroism (ECD) data analyses, respectively. Compounds 1–3 possess a hydroxyl-substituted chiral center on the aliphatic bibenzyl bridge, which represented the first examples of natural bibenzyl enantiomers from the genus of Bletilla. The antibacterial, antitumor necrosis factor (anti-TNF-α), and neuroprotective effects of the isolates have been evaluated. Compounds 3a and 3b were effective against three Gram-positive bacteria with minimum inhibitory concentrations (MICs) of 52–105 μg/ml. Compounds 2a and 2b exhibited significant inhibitory effects on TNF-α-mediated cytotoxicity in L929 cells with IC50 values of 25.7 ± 2.3 μM and 21.7 ± 1.7 μM, respectively. Subsequently, the possible anti-TNF-α mechanism of 2 was investigated by molecular docking simulation. Furthermore, the neuroprotective activities were tested on the H2O2-induced PC12 cell injury model, and compounds 2b, 3a, and 3b (10 μM) could obviously protect the cells with the cell viabilities of 57.86 ± 2.08%, 64.82 ± 2.84%, and 64.11 ± 2.52%, respectively.

Shanpanootols G and H, Diterpenoids from the Rhizomes of Kaempferia pulchra Collected in Myanmar and Their Vpr Inhibitory Activities.

Two new trihydroxy derivative of Δ8(14),15-isopimarane diterpenoids, shanpanootols G (1) and H (2), along with three known analogues were isolated from the ethyl acetate-soluble extract of Kaempferia pulchra rhizomes collected in Shan State of Myanmar. The structures of these compounds including their absolute configurations were elucidated by the combination of one dimensional (1D) and 2D-NMR spectroscopic methods, high resolution mass spectrometric technique, and the experimental and the calculated electronic circular dichroism (ECD) data. The isopimarane diterpenoids (1-5) were tested for their Viral protein R (Vpr) inhibitory activities against TREx-HeLa-Vpr cells. Shanpanootol H (2) and (1R,2S,5S,9R,10S,13R)-1,2-dihydroxypimara-8(14),15-dien-7-one (4) exhibited anti-Vpr activities at the 5 µM treated dose.

Biological and chemical characterization of antimicrobial activity in Arthrobacter spp. isolated from disease-suppressive compost.

Antagonistic bacteria can act as biocontrol agents against various phytopathogens. Recently, Arthrobacter spp. demonstrated antifungal activity, but were not further characterized. In this study, the antimicrobial activity of Arthrobacter humicola strains M9-1A, M9-2, and M9-8, and Arthrobacter psychrophenolicus strain M9-17 were evaluated against nine plant pathogens in vitro, and their cell-free filtrates were additionally assessed for inhibition of Alternaria alternata and suppression of black mold disease on tomato fruit. Results indicated that A. humicola M9-1A and A. psychrophenolicus M9-17 were the most inhibitory, reducing growth of seven of the pathogens studied. Cell-free filtrates of A. psychrophenolicus M9-17 reduced the growth of most pathogens. All cell-free bacterial filtrates, except those from A. humicola M9-2, suppressed black mold on tomato fruit. Disk diffusion assays with ethyl acetate soluble culture filtrate extracts of all bacteria reduced the mycelial growth of A. alternata. Clear inhibition zones were observed for A. psychrophenolicus M9-17 extracts using drop bioassays. The antifungal compound N-acetyltryptamine was purified and characterized from the A. psychrophenolicus M9-17 cell-free ethyl acetate soluble extract. This study suggests that antibiosis may play a key role in the antimicrobial activity of Arthrobacter spp.

Phytochemical constituents and extracts of the roots of Scutellaria baicalensis exhibit in vitro and in vivo control efficacy against various phytopathogenic microorganisms

Scutellaria baicalensis is one of the most well-known medicinal herbs used in traditional Chinese herbal medicine. During our search of antimicrobial botanicals, the methanol extract from the roots of S. baicalensis displayed in vivo control efficacy against various fungal plant diseases and in vitro inhibition against phytopathogenic bacteria. In an in vitro antifungal bioassay, ethyl acetate-soluble extract was highly active against the growth of Magnaporthe oryzae and Phytophthora sp. mycelia in the range of 500 to 5000 µg/mL. Through antifungal activity-guided bioassay, bioactive flavonoids and an oligosaccharide were identified from the EtOAc soluble extract of S. baicalensis roots by ESI-MS and 1D- and 2D-NMR data analyses. These constituents were assessed for their in vitro and in vivo antifungal activities. The major bioactive flavonoids SB1 (wogonin), SB4 (baicalein), and SB5 (baicalin) in the extracts of S. baicalensis’s roots were quantified by HPLC method. Among these three compounds, SB1 exhibited the best in vitro antifungal effect against M. oryzae and in vivo efficacy (63%) against rice blast at 500 µg/mL. SB4 was the most active against plant bacteria Acidovorax avenae subsp. cattlyae, Clavibacter michiganensis subsp. michiganensis, and Ralstonia solanacearum with an MIC value of 19 µg/mL. Moreover, the emulsion-type formulation containing the ethyl acetate-soluble extract of S. baicalensis significantly suppressed the development of rice blast caused and rice leaf blight on the rice plants in vivo. This is the first report that demonstrated bioactive constituents and extracts derived from S. baicalensis plants, which are promising to develop botanical fungicide and bactericide to control various plant diseases.

Extracts and metabolites derived from the leaves of Cassia alata L. exhibit in vitro and in vivo antimicrobial activities against fungal and bacterial plant pathogens

The use of synthetic chemicals in agriculture has not only caused humans and animals’ health risks but also environmental pollution. Botanical pesticides have been considered as alternatives to harmful pesticides because of their low toxicity and easy biodegradable property. The objective of this study was to evaluate the antimicrobial activities of the extracts and metabolites from the leaves of Cassia alata L. against fungal and bacterial phytopathogens. Ethyl acetate-soluble extract derived from C. alata leaves has been found to remarkably control the plant diseases caused by fungi Magnaporthe oryzae, Phytophthora infestans, Colletotrichum coccodes and Puccinia recondita in vivo. To provide scientific evidence on the effectiveness of the ethyl acetate-soluble extract against plant pathogens, the bioassay-guided fractionation of the extract was conducted and thereby eight compounds including methyl 2,4,6-trihydroxybenzoate (1), aloe-emodin (2), kaempferol (3), (-)-epiafzelechin (4), rhein (5), kaempferol-3-O-glycoside (6), kaempferol-3-O-gentiobiside (7) and aloe-emodin-8-O-β-D-glucoside (8) were identified. The content of 2, 5, and 8 in the ethyl acetate-soluble extract and methanol extract of C. alata leaves were quantified by HPLC analysis. Compounds 3-8 displayed in vitro antifungal activity against M. oryzae and Phytophthora species. Out of the isolated compounds, rhein (5) displayed the best antifungal activity; it strongly inhibited in vitro the mycelial growth of Phytophthora species and effectively suppressed tomato late blight (TLB) by 57.1 % at 150 μg/mL and 87.9 % at 300 μg/mL on the tomato seedlings in vivo. Besides, rhein showed excellent in vitro inhibition for the bacterial growth of Acidovorax avenae subsp. cattlvae with an IC50 of 2.5 μg/mL. From the results, it was confirmed that the ethyl acetate-soluble extract derived from C. alata leaves contains antimicrobial constituents against various plant pathogens and has potent in vivo efficacy for controlling plant diseases.

Synergistic Protection by Isoquercitrin and Quercetin against Glutamate-Induced Oxidative Cell Death in HT22 Cells via Activating Nrf2 and HO-1 Signaling Pathway: Neuroprotective Principles and Mechanisms of Dendropanax morbifera Leaves.

Dendropanax morbifera leaves (DML) have long been used as traditional medicine to treat diverse symptoms in Korea. Ethyl acetate-soluble extracts of DML (DMLE) rescued HT22 mouse hippocampal neuronal cells from glutamate (Glu)-induced oxidative cell death; however, the protective compounds and mechanisms remain unknown. Here, we aimed to identify the neuroprotective ingredients and mechanisms of DMLE in the Glu-HT22 cell model. Five antioxidant compounds were isolated from DMLE and characterized as chlorogenic acid, hyperoside, isoquercitrin, quercetin, and rutin by spectroscopic methods. Isoquercitrin and quercetin significantly inhibited Glu-induced oxidative cell death by restoring intracellular reactive oxygen species (ROS) levels and mitochondrial superoxide generation, Ca2+ dysregulation, mitochondrial dysfunction, and nuclear translocation of apoptosis-inducing factor. These two compounds significantly increased the expression levels of nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in the presence or absence of Glu treatment. Combinatorial treatment of the five compounds based on the equivalent concentrations in DMLE showed that significant protection was found only in the cells cotreated with isoquercitrin and quercetin, both of whom showed prominent synergism, as assessed by drug–drug interaction analysis. These findings suggest that isoquercitrin and quercetin are the active principles representing the protective effects of DMLE, and these effects were mediated by the Nrf2/HO-1 pathway.

In vivo bioactivity-guided isolation of antifertility fraction of Waltheria indica Linn. root in male Wistar rats

BackgroundWaltheria indica is a multipurpose medicinal plant with abundance of phytochemical compounds. Antifertility effect of Waltheria indica Linn. root and leaves have been reported. However, the fraction responsible for this antifertility effect needs to be isolated for possible male contraceptive purpose. Therefore, this research was designed to isolate the antifertility fraction of Waltheria indica Linn. root (WILR) in an in vivo model using male Wistar rats. Crude ethanol extract of WILR was sequentially dissolved in hexane, dichloromethane, and ethyl acetate. Rats (n = 5) were administered with 200, 500, or 1000 μg/kg of hexane, dichloromethane, and ethyl acetate soluble extracts of WILR, while control received distilled water, daily for 15 days to determine the soluble extract with most antifertility effect. Thereafter, fractions were separated from dichloromethane soluble WILR extract by column and thin-layer chromatography. Rats (7 groups, n = 5) were administered with each of the fractions (DF1 to DF7; at 1000 μg/kg) to determine the fraction with the highest antifertility. Rats were thereafter sacrificed, and sperm parameters, reproductive hormones, testicular cholesterol, and protein were determined according to standard procedure. Histology of the testis was also done. Data were analyzed using ANOVA at p ≤ 0.05.ResultsDichloromethane soluble fraction (500 μg/kg) significantly decreased sperm concentration (137.00 ± 9.85 to 107.00 ± 13.08 × 106 cells/mL), levels of testosterone (2.90 ± 0.65 to 1.50 ± 0.37 ng/mL), and FSH (0.08 ± 0.08 to 0.99 ± 0.08 IU/L). The dichloromethane soluble fraction also caused the loss of testicular interstitium and spermatogenic cells. DF5 significantly reduced sperm motility (92.00 ± 2.74 to 76.00 ± 5.48%) and LH (2.86 ± 0.52 to 1.47 ± 0.18 IU/L). DF5 also significantly increased levels of prolactin (1.22 ± 0.10 to 1.88 ± 0.48 ng/mL), testicular total protein (7.36 ± 0.35 to 8.54 ± 1.06 g/dL), and testicular cholesterol (34.17 ± 3.65 to 55.76 ± 6.08 mg/mL).ConclusionThe results indicate that the DF5 is the bioactive fraction of WILR responsible for its antifertility effect. The possible antifertility mechanisms are through the reduction in sperm parameters, reproductive hormones, and histological changes in the testis.

Shanpanootols A-F, diterpenoids from Kaempferia pulchra rhizomes collected in Myanmar and their Vpr inhibitory activities

Six new isopimarane diterpenoids, shanpanootols A-F (1–6), along with two known analogues, were isolated from the ethyl acetate-soluble extract of Kaempferia pulchra rhizomes collected in Myanmar. The structures of these compounds were elucidated by extensive spectroscopic techniques such as 1D and 2D NMR and HRESIMS. The absolute configuration of 1 was determined by the modified Mosher method. The new isolates (1–6) were tested for their Vpr inhibitory activities against TREx-HeLa-Vpr cells. Shanpanootols C (3) and E (5) inhibited Vpr at doses of 2.5 and 5 μM, respectively.

Identification of chemical constituents in ethyl acetate soluble extract of Sinopodophylli Fructus based on HPLC-MS~n

A high performance liquid chromatography with a diode array detector combined with electrospray ionization ion trap time-of-flight multistage mass spectrometry(HPLC-DAD-ESI-IT-TOF-MS~n, HPLC-MS~n) method was established for qualitative analysis of the chemical components of ethyl acetate extract from Sinopodophylli Fructus. The analysis was performed on a Kromasil 100-5 C_(18)(4.6 mm×250 mm, 5 μm) column, with a mobile phase consisted of 0.1% formic acid(A) and acetonitrile(B) for gradient at a flow rate of 1.0 mL·min~(-1). Electrospray ionization ion trap time-of-flight multistage mass spectrometry was applied for qualitative analysis under positive and negative ion modes. With use of reference substance, characteristic fragmentation and their HR-MS data, 102 components were identified, including 67 flavonoids and 35 lignans. Among them, 45 compounds were reported in Sinopodophylli Fructus for the first time and 19 compounds were identified as new compounds. PharmMapper was used to predict the bioactivity of compounds that were first reported in Sinopodophylli Fructus, and 20 compounds of them were identified to have potential anticancer activity. The results showed that there were many isomers in the ethyl acetate extract of Folium Nelumbinis, and a total of 19 groups of isomers were found. Among them, C_(21)H_(20)O_8 had the highest number of isomers(18 compounds), all of which were α-peltatin or its isomers; C_(21)H_(20)O_7 ranked second, with 10 compounds, all of which were 8-prenylquercetin-3-methyl ether or its isomers. In conclusion, an HPLC-MS~n method was established for qualitative analysis of the ethyl acetate extract(with anti-breast cancer activity) from Sinopodophylli Fructus in this study, which will provide the evidence for clarifying pharmacological active ingredients of the ethyl acetate extract from Sinopodophylli Fructus against breast cancer.

New Neo-Lignan From Acanthopanax senticosus and the Cytotoxic Effects on Human Cancer Cell Lines

A new neo-lignan named (7ʹS,8ʹR)-4ʹ,5ʹ,9ʹ-trihydroxy-5-methoxy-4,8ʹ-oxyneolign-7-en-9-al (1), together with 5 known compounds (2-6) were isolated from the ethylacetate-soluble extract of Acanthopan...

New Neo-Lignan From Acanthopanax senticosus and the Cytotoxic Effects on Human Cancer Cell Lines

A new neo-lignan named (7ʹ S,8ʹ R)-4ʹ,5ʹ,9ʹ-trihydroxy-5-methoxy-4,8ʹ-oxyneolign-7-en-9-al (1), together with 5 known compounds (2-6) were isolated from the ethylacetate-soluble extract of Acanthopanax senticosus. The structure of new neo-lignan was elucidated with spectroscopic and physicochemical analyses. All the isolates were evaluated for in vitro cytotoxicity against 4 human cancer lines including HepG2, A549, Hela, and MCF-7. Among them, compounds 1 and 3 showed the potent antiproliferative activities against the HepG2 cancer cells with half-maximal inhibitory concentration (IC50) values of 9.8 ± 1.6 and 15.0 ± 1.1 μM, respectively. In addition, compound 6 exhibited moderate inhibitory activity on MCF-7 cancer cells with an IC50 value of 18.3 ± 1.5 μM.

A stilbene dimer and flavonoids from the aerial parts of Chromolaena odorata with proprotein convertase subtilisin/kexin type 9 expression inhibitory activity.

Investigation of components of the chloroform-soluble and ethyl acetate-soluble extracts of the aerial parts of Chromolaena odorata L. selected by PCSK9 mRNA expression monitoring assay in HepG2 cells led to the isolation of a new stilbene dimer, (+)-8b-epi-ampelopsin A (1), and 30 known compounds (2-31). The structures of the isolates were established by interpretation of NMR spectroscopic data and the stereochemistry of the new stilbene (1) was proposed based on ECD and NMR calculations. Among the isolates, 1, 5,6,7,4'-tetramethoxyflavanone (6), 5,6,7,3',4'-pentamethoxyflavanone (7), acacetin (18), and uridine (21) were found to inhibit PCSK9 mRNA expression with IC50 values of 20.6, 21.4, 31.7, 15.0, and 13.7µM, respectively. Furthermore, the most abundant isolate among the selected compounds, 6, suppressed PCSK9 and low-density lipoprotein receptor protein expression in addition to downregulating the mRNA expression of HNF-1α.

Anti-viral activity of culinary and medicinal mushroom extracts against dengue virus serotype 2: an in-vitro study

BackgroundDengue is a mosquito-borne viral infection that has become a major public health concern worldwide. Presently, there is no specific vaccine or treatment available for dengue viral infection.MethodsLignosus rhinocerotis, Pleurotus giganteus, Hericium erinaceus, Schizophyllum commune and Ganoderma lucidium were selected for evaluation of their in-vitro anti-dengue virus serotype 2 (DENV-2) activities. Hot aqueous extracts (HAEs), ethanol extracts (EEs), hexane soluble extracts (HSEs), ethyl acetate soluble extracts (ESEs) and aqueous soluble extracts (ASEs) were prepared from the selected mushrooms. The cytotoxic effects of the extracts were evaluated by the MTT assay. The anti-DENV-2 activities of the extracts were evaluated in three different assays: simultaneous, attachment and penetration assays were perfomed using plaque reduction assays and RT-qPCR assays. The effect of the addition time on viral replication was assessed by the time of addition assay, and a virucidal assay was carried out to evaluate the direct effect of each mushroom extract on DENV-2. The chemical composition of glucans, and the protein and phenolic acid contents in the extracts were estimated.ResultsWe found that the HAEs and ASEs of L. rhinocerotis, P. giganteus, H. erinaceus and S. commune were the least toxic to Vero cells and showed very prominent anti-DENV2 activity. The 50% inhibitory concentration (IC50) values of the ASEs ranged between 399.2–637.9 μg/ml, while for the HAEs the range was 312.9–680.6 μg/ml during simultaneous treatment. Significant anti-dengue activity was also detected in the penetration assay of ASEs (IC50: 226.3–315.4 μg/ml) and HAEs (IC50: 943.1–2080.2 μg/ml). Similarly, we observed a marked reduction in the expression levels of the ENV and NS5 genes in the simultaneous and penetration assays of the ASEs and HAEs. Time-of-addition experiments showed that the highest percent of anti-DENV2 activity was observed when the mushroom extracts were added immediately after virus adsorption. None of the extracts exhibited virucidal effect. Chemical composition analysis showed that the major components in the mushroom HAEs and ASEs were glucan (beta D-glucan) and proteins, however, there was no significant correlation between the anti-dengue activity and the concentration of glucans and proteins.ConclusionThese findings demonstrated the potential of mushroom extracts as anti-dengue therapeutic agents with less toxic effects.

Bioactive Seco-Lanostane-Type Triterpenoids from the Roots of Leplaea mayombensis.

Fractionation of the ethyl acetate-soluble extract of the roots of Leplaea mayombensis afforded two new 3,4-seco-lanostane-type triterpenoids, leplaeric acids A and B (1, 2), the new lanostane-type triterpenoid leplaeric acid C (3), and six known natural products (5-10). Derivatization of the main constituent, 1, afforded the dimethyl ester 4, the monoamide 11, and diamide 12 for SAR studies. The structures of these compounds were established through spectroscopic methods, and a single-crystal X-ray diffraction analysis was used to confirm the relative configuration of compound 1. These lanostane derivatives are unique since they are the first C-21-oxygenated lanostanes isolated from plant sources. Preliminary biological assays against the MDA MB 231 breast cancer cell line showed that compounds 1, 2, 4, and 11 have modest cytotoxic activity. Compound 2 was the most active, with an IC50 of 55 ± 7 μM. From these results, the amides (11, 12) derived from triterpenoid1 were found to be less active than the derived esters (2, 4).

Antimicrobial efficacy of extracts and constituents fractionated from Rheum tanguticum Maxim. ex Balf. rhizomes against phytopathogenic fungi and bacteria

The antimicrobial efficacies of extracts and constituents fractionated from Rheum tanguticum rhizomes were evaluated by using in vitro and in vivo bioassay against seven phytopathogenic fungi and ten pathogenic bacteria, respectively. Dichloromethane and ethyl acetate soluble extracts derived from R. tanguticum rhizomes effectively controlled plant diseases caused by five fungi Magnaporthe oryzae, Blumeria graminis f. sp. hordei, Colletotrichum coccodes, Phytophthora infestans, and Puccinia recondita in in vivo whole plant bioassay. In addition, these extracts showed strong inhibitory activity against the bacterial growth of Acidovorax avenae subsp. cattlyae (Aac), Clavibacter michiganensis subsp. michiganensis, Xanthomonas arboricola pv. pruni (Xap), and Pseudomonas syringae pv. actinidiae (Psa), with MIC values ranging from 125 to 250μg/mL. The active extracts of R. tanguticum rhizomes were fractionated by using various and repeated chromatographic techniques to yield seven constituents that included three anthraquinones and four stilbenes. Notably, at concentrations ranging from 75 to 300μg/mL, physcion (DH03) and chrysophanol (DH04) were significantly effective in suppressing the development of barley powdery mildew (BPM) caused by B. graminis f. sp. hordei, with control values from 80 to 96.7%. Moreover, stilbenes rhapontigenin (DH02) and desoxyrhapontigenin (DH05) had a broad spectrum and potent activity against phytopathogenic bacteria; DH05 effectively inhibited the bacterial growth of Aac, Burkholderia glumae and Psa at MICs ranging from 38 to 150μg/mL. In this paper, we report their antibacterial activity for the first time. The botanical materials containing anthraquinones and stilbenes were active against both phytopathogenic fungi and bacteria. These results suggested that R. tanguticum rhizomes could be used as a new source of antimicrobial substances for developing a botanical fungicide and bactericide to control plant diseases.

Antibacterial Activity of the Isolation Ethyl Acetate-Soluble Extract Noni Fruit (Morindra citrifolia L.) against Meat Bacterial Decay

Noni (Morindra citrifolia L.) is native to Indonesia which have medicinal properties. One of them as an antibacterial. This study aims to determine the antibacterial activity of isolates from the ethanol extract noni fruit to bacterial decay meat is Bacillus licheniformis, Klebsiella pneumonia, Bacillus alvei, Acinetobacter calcoaceticus, and Staphylococcus saprophyticus. The extraction process using the maceration method, and then made a partition by centrifugation ethyl acetate. Soluble part partition showed bacterial growth inhibition activity of the strong to very strong. Furthermore, the ethyl acetate soluble partition on preparative thin layer chromatography produced 5 isolates. Isolates obtained antibacterial activity test performed with a concentration of 20% and 30%. The results of antibacterial test against bacteria test isolates, showing isolates A can not inhibit the growth of bacteria, isolates B and C have medium activity and strong, isolates D and E isolates have activity against bacteria that were tested. MIC and MBC test results showed that the isolates B gives an inhibitory effect (bacteriostatic) against all bacteria. Content analysis of compounds by TLC using the reagents cerium (IV) sulfate indicates a phenol group. Isolates B contains a major compound which can be used as an antibacterial candidate in food preservation replace chemical preservatives.

Identification of Pyrogallol in the Ethyl Acetate-Soluble Part of Coffee as the Main Contributor to Its Xanthine Oxidase Inhibitory Activity.

In this study, ethyl acetate-soluble parts of hot-water extracts from roasted coffee beans were found to demonstrate potent xanthine oxidase (XO) inhibition. The XO inhibitory activities and chlorogenic lactone contents (chlorogenic lactones have previously been identified as XO inhibitors in roast coffee) were measured for ethyl acetate-soluble parts prepared from coffee beans roasted to three different degrees. Although chlorogenic lactone contents decreased with higher degrees of roasting, the XO inhibitory activity did not decrease. These data led us to investigate new potent inhibitors present in these ethyl acetate-soluble extracts. Repeated assay-guided purifications afforded a highly potent XO inhibitor, which was eluted before chlorogenic lactones via medium-pressure chromatography using an octadecylsilica gel column. The obtained inhibitor was identified as pyrogallol (1,2,3-trihydroxybenzene), which had an IC50 of 0.73 μmol L-1, much stronger than that of other related polyphenolic compounds. Quantitative analysis of pyrogallol and chlorogenic lactones revealed that pyrogallol (at concentrations of 33.9 ± 4.2 nmol mL-1 in light roast coffee and 39.4 ± 3.9 nmol mL-1 in dark roast coffee) was the main XO inhibitor in hot-water extracts of roasted coffee beans (i.e., drinking coffee).