Antioxidative activity of volatile extracts isolated from Angelica tenuissimae roots, peppermint leaves, pine needles, and sweet flag leaves

Volatile extracts were isolated from dried medicinal plants [Angelica tenuissimae roots (AT, Angelica tenuissima Nakai), peppermint leaves (PL, Mentha arvensis L.), pine needles (PN, Pinus sylvestris L.), and sweet flag leaves (SF, Acorus gramineus Rhizoma)] using steam distillation under reduced pressure, followed by continuous liquid-liquid extraction (DRP-LLE). The extracts were then analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The major volatile constituents of AT, PL, PN, and SF were 3-butylidene-4,5-dihydrophthalide (32 mg/g), menthol (18 mg/g), thunbergol (2.1 mg/g), and cis-asarone (37 mg/g), respectively. The inhibitory activity (%) of the extracts against hexanal oxidation ranged from 33 to 98% at a level of 50 microg/mL. Among the volatile extracts, PL and PN increased cell viabilities by 10 and 24%, respectively, at a dose of 1 microg/mL, compared to that of H2O2-treated brain neuroblastoma cells, SK-N-SH. However, a 20% reduction in the malonaldehyde level, an index for lipid peroxidation, was observed at only 1 microg/mL concentration of PN.     

Antioxidant activities of abietane diterpenoids isolated from Torreya nucifera leaves

Investigation on antioxidant compounds from the ethanolic extracts of Torreya nucifera leaves resulted in the isolation of abietane diterpenoids, a known 18-methylesterferruginol (1) and a new 18-dimethoxyferruginol (2). The structures of compounds 1 and 2 were elucidated on the basis of their spectroscopic analyses. Compounds 1 and 2 inhibited the Cu2+-mediated, 2,2'-azobis(2-amidinopropane)hydrochloride-mediated and 3-morpholinosydnonimine-1-mediated low-density lipoprotein (LDL) oxidation in the thiobarbituric acid-reactive substances assay as well as the macrophage-mediated LDL oxidation. Compounds 1 and 2 exhibited the potent antioxidant activities in the conjugated diene production, relative electrophoretic mobility, and apoB-100 fragmentation on copper-mediated LDL oxidation. Compound 1 also suppressed nitric oxide production and inducible nitric oxide synthase expression in lipopolysaccharide-stimulated RAW264.7 cells.     

Anticancer activities of thelephantin O and vialinin A isolated from Thelephora aurantiotincta

Thelephora aurantiotincta is an edible mushroom belonging to the genus Thelephora; it grows in symbiosis with pine trees. Recently, phytochemical investigations have revealed that the genus Thelephora is an abundant source of p-terphenyl derivatives. However, their bioactivity has not yet been well characterized. In screening for natural materials with anticancer activity, a T. aurantiotincta ethanol extract (TAE) was found to decrease cell viability in human hepatocellular carcinoma cells (HepG2). In this study, a new p-terphenyl derivative, thelephantin O, and a known compound, vialinin A, were isolated as the principal bioactive components of TAE. These compounds decreased cell viability in HepG2 and human colonic carcinoma cells (Caco2), but not in noncancerous human hepatocytes. This is the first report of the isolation from T. aurantiotincta of selective cytotoxic agents against cancer cells.     

Insecticidal, anti-juvenile hormone, and fungicidal activities of organic extracts from different Penicillium species and their isolated active components.

Organic extracts from mycelium and culture broth of 21 Penicillium isolates have been tested for insecticidal, insect anti-juvenile hormone (anti-JH), and antifungal activities. Culture broth extracts were the most active, mainly against insects; nearly 25% of them have shown high entomotoxicity (100% mortality at 100 microg/cm(2)). A strong in vivo anti-JH activity against Oncopeltus fasciatus Dallas was detected in the culture broth extracts from P. brevicompactum P79 and P88 isolates. The two new natural products isolated from P79, N-(2-methyl-3-oxodec-8-enoyl)-2-pyrroline (1) and 2-hept-5-enyl-3-methyl-4-oxo-6,7,8,8a-tetrahydro-4H-pyrrolo[2,1-b]-1, 3-oxazine (2), possessed anti-JH and insecticidal activity, respectively, against O. fasciatus. Synthesized natural compound 1 has shown an ED(50) of 0.7 microg/nymph when assayed on newly molted fourth-instar nymphs of O. fasciatus. Promising biological activities have also been detected in the synthetic precursors.     

不同水分含量对潮土和火山灰土硝化动态的影响

在试验室条件下研究了不同水分含量对取自中国的潮土和日本的火山灰土硝化动态的影响。潮土在土壤硝化过程中的土壤水分含量以田间持水量的60%～90%较为适宜,低于田间持水量的60%引起土壤硝化力降低。火山灰土在土壤硝化中的土壤水分含量以田间持水量的75%～90%较为适宜,低于田间持水量的75%引起土壤硝化力降低。潮土在硝化培养中有亚硝酸盐出现,火山灰土没有亚硝酸盐被检出。土壤亚硝酸盐含量在低水分含量下峰值低,持续时间较长,在高水分含量下峰值高,持续时间较短。     

Antioxidative and antimutagenic activities of 4-vinyl-2,6-dimethoxyphenol (canolol) isolated from canola oil

A potent antioxidative compound in crude canola oil, canolol, was recently identified, and reported herein are studies of its scavenging capacity against the endogenous mutagen peroxynitrite (ONOO(-)). ONOO(-) is generated by the reaction between superoxide anion radical and nitric oxide, both of which are produced by inflammatory leukocytes. Among various antioxidative substances of natural or synthetic origin, canolol was one of the most potent antimutagenic compounds when Salmonella typhimurium TA102 was used in the modified Ames test. Its potency was higher than that of flavonoids (e.g., rutin) and alpha-tocopherol and was equivalent to that of ebselen. Canolol suppressed ONOO(-)-induced bactericidal action. It also reduced intracellular oxidative stress and apoptosis in human cancer SW480 cells when used at a concentration below 20 microM under H(2)O(2)-induced oxidative stress. In addition, canolol suppressed plasmid DNA (pUC19) strand breakage induced by ONOO(-), as revealed by agarose gel electrophoresis.     

Characterization of a chitosanase isolated from a commercial ficin preparation

A chitosanolytic enzyme was purified from a commercial ficin preparation by affinity chromatographic removal of cysteine protease on pHMB-Sepharose 4B and cystatin-Sepharose 4B and gel filtration on Superdex 75 HR. The purified enzyme exhibited both chitinase and chitosanase activities, as determined by SDS-PAGE and gel activity staining. The optimal pH for chitosan hydrolysis was 4.5, whereas the optimal temperature was 65 degrees C. The enzyme was thermostable, as it retained almost all of its activity after incubation at 70 degrees C for 30 min. A protein oxidizing agent, N-bromosuccinimide (0.25 mM), significantly inhibited the enzyme's activity. The molecular mass of the enzyme was 16.6 kDa, as estimated by gel filtration. The enzyme showed activity toward chitosan polymers exhibiting various degrees of deacetylation (22-94%), most effectively hydrolyzing chitosan polymers that were 52-70% deacetylated. The end products of the hydrolysis catalyzed by this enzyme were low molecular weight chitosan polymers and oligomers (11.2-0.7 kDa).     

Prediction of potentially mineralizable N from amidohydrolase activities in a manure-applied, corn residue-amended soil

Prediction of potentially mineralizable N as an important N pool from soil amidohydrolases was investigated. Composite soil samples were collected from plots of a field experiment in which 0, 50 and 100 Mg cow manure ha⁻¹ year⁻¹ had been applied for five consecutive years. The soils were treated with corn shoots or roots or remained untreated in a factorial combination with the manure treatments, with three replications. The mineralized inorganic N was measured periodically in 20-week incubations and potentially mineralizable N (N₀) was calculated based on a first-order kinetic model. Urease, l-glutaminase and l-asparaginase activities were measured before and after incubation. The values of N₀ ranged from 208.6 in the controls to 388.4 in soils that had received 50 Mg ha⁻¹ year⁻¹ of cow manure and were amended with corn shoots. Corn residue amendment in the manure treated soils, increased the values of N₀ or changed the N mineralization kinetic pattern from a first-order to a zero-order model. According to a relative sensitivity index, l-asparaginase was the most sensitive enzyme to the treatments. Multiple regression analysis revealed that 92% of N₀ variations can be described by the activities of urease and l-asparaginase and therefore the soil amidohydrolase activities have the potential to evaluate potentially mineralizable N.     

Characteristics of an amidase isolated from a soil bacterium

Amidase was extracted from a bacterium isolated from soil, and its properties were compared with those of amidase in soil. Amidase activity of the bacterial protein was lower than that of soil amidase, respectively, in its optimal pH (7.0 vs 8.5), optimal temperature (50 vs 60°C), K_m constant calculated by the Lineweaver-Burk plot (5.6 vs 17.9 mm), activation energy (18.9 vs 43.3 kJmol^?) and Q₁₀ (av. = 1.28 vs 1.75). Bacterial amidase was stable at temperatures ranging from 10 to 50°C and denatured at 55°C. Toluene inhibited both bacterial and soil amidase.When the inhibitions by 21 trace elements were compared by using 2 μmol 0.1 mg^?1 protein, the most effective inhibitors of bacterial amidase (> 25% inhibition) were: Ag(I), Cd(II), Cu(II), Hg(II), Ni(II), Pb(II), Zn(II), Al(III) and Se(IV). The effect of 16 pesticides on bacterial amidase varied considerably. By using 2 μg of active ingredient of pesticide 0.1 mg^?1 protein, the inhibition of bacterial amidase ranged from 7 to 49% with Dinitroamine and Butylate, respectively. The results show that soil constituents have a considerable influence on the reaction catalyzed by this enzyme.     

Antimutagenicity of some edible Thai plants,and a bioactive carbazole alkaloid,mahanine, isolated from Micromelum minutum

The antimutagenic activity against Trp-P-1 of methanolic extracts of 118 samples (108 species) of edible Thai plants was examined by the Ames Test. The activity was evaluated by the amount of plant extracts which suppressed 90% of the mutagenesis (ED90). Five plants, Micromelum minutum, Oroxylum indicum, Cuscuta chinensis, Azadirachta indica, and Litsea petiolata, exhibited significant activity with antimutagenic ED90 values lower than 5 microL/plate (0.1 mg of dry plant material equivalent). The activity-guided fractionation of the extract of M. minutum, which exhibited the highest antimutagenic activity in the screening, resulted in the isolation of an active principle, (+)-mahanine (1) as confirmed by its physicochemical properties. Compound 1 showed a wide variety of biological activity, including antimutagenicity against heterocyclic amines such as Trp-P-1 with an IC50 of 5.2 microM, cytotoxicity against a tumor cell line HL60 with a MIC100 of 4.0 microg/mL, and antimicrobial activity against Bacillus cereus and Staphylococcus aureus with MIC100 values of 6.25 and 12.5 microg/mL, respectively.     

Antifungal synergistic effect of scopoletin, a hydroxycoumarin isolated from Melia azedarach L. fruits

In the continuous search for antifungal compounds from plants, the hydroxycoumarin scopoletin (1) was isolated from seed kernels of Melia azedarach L. from which three other compounds, vanillin (2), 4-hydroxy-3-methoxycinnamaldehyde (3), and (+/-) pinoresinol (4), have also been isolated. Guided fractionation through autobiography on TLC using Fusarium verticillioides (Saccardo) Nirenberg as test organism led to the isolation of 1, which exhibited a minimum inhibitory concentration (MIC) of 1.50 mg/mL in the microbroth dilution method. Despite its own weak activity, when the coumarin was combined with the above-mentioned compounds, a strong enhancement of the antifungal effect was observed, even showing a complete inhibition in the growth of the pathogen when 1 was added at a concentration of up to 5% of its MIC value. The same level of effectiveness was observed when the synthetic antifungal agents Mancozeb and Carboxin were each combined with compounds 1-4, in which cases it became possible to decrease the effective concentrations of these commercial compounds by up to 2.5 and 3%, respectively.     

Propolin G, a prenylflavanone, isolated from Taiwanese propolis, induces caspase-dependent apoptosis in brain cancer cells

We have previously shown that six propolins, A-F, could be isolated from Taiwanese propolis (TP) and that they exerted a broad spectrum of biological activities. Recently, we isolated a seventh compound, propolin G. Its chemical structure has been identified by NMR and fast atom bombardment-mass spectrometry spectra and was found to be identical to a known compound, nymphaeol C. We used high-performance liquid chromatography to determine the relative contents of propolins C, D, F, and G in TP collected in various seasons and regions and found them to be relatively higher in TPs collected from May to July than from September to October. In our present study, we were interested in the various biological activities of TP extract as well as in propolin G as a pure compound. We found that propolin G could efficiently induce apoptosis in brain cancer cell lines (glioma and glioblastoma). The apoptosis might have been through a mitochondrial- and caspase-dependent pathway. This result demonstrated that the TP collection season was more an important factor than the geographical region. Propolis has been suggested to possess a potent antioxidant activity. We further evaluated the antioxidant property of propolin G using DPPH (1,2-diphenyl-2-picryhydrazyl). Our results indicate that propolin G does possess free radical scavenging activity. We also evaluated the neuroprotective action of propolin G, TP, and BP (Brazilian propolis) extracts against oxidative stress in rat primary cortical neurons. Our data demonstrate that propolin G and TP extracts have a marked neuroprotective effect that is greater than BP extract. In conclusion, the isolation and characterization of propolin G from TP have demonstrated for the first time that this compound is a potent inducer of apoptosis in brain cancer cells and that this compound and TP extract exhibit a protective effect against oxidative stress in rat cortical neurons.     

Structures of new triterpenoids and cytotoxicity activities of the isolated major compounds from the fruit of Momordica charantia L

Two new cucurbitane-type triterpene glycosides, charantagenins D (1) and E (2), and one new sterol, 7-oxo-stigmasta-5,25-diene-3-O-β-d-glucopyranoside (3), were isolated from the fruit of Momordica charantia L. together with another eight known compounds. Their structures were determined on the basis of spectral analysis. Cytotoxicity activities of the isolated major compounds were evaluated against lung cancer cell line A549, glioblastoma cell line U87, and hepatoma carcinoma cell line Hep3B by using a 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) in vitro assay. Results showed compounds 1 and 7 (goyaglycoside d) with an -OMe substituent group in the side chain exhibited significant cytotoxic activities against cancer cells. Impressively, the IC(50) values of the new compound 1 to A549, U87, and Hep3B were 1.07, 1.08, and 14.01 μmol/L, respectively, which were much lower than those of other tested compounds.     

TNT nitroreductase from a Pseudomonas aeruginosa strain isolated from TNT-contaminated soil

Microbial degradation and detoxification of TNT (2,4,6-trinitrotoluene) in soils ultimately depends on the presence of effective intracellular or extracellular enzymes. TNT was rapidly degraded by an enzyme obtained from a Pseudomonas aeruginosa strain isolated from TNT-contaminated soil. The nitroreductase enzyme was purified to apparent electrophoretic homogeneity by sequential chromatography on phenyl-sepharose, hydroxyapatite, and ion exchange resins. The TNT-nitroreductase catalyzed reduction of TNT to 4-hydroxylamino-4,6-dinitrotoluene (4HADNT) and 4-amino-2,6-dinitrotoluene (4ADNT). TNT reduction to 4ADNT in cell-free enzyme preparations corresponded to 2ADNT production by intact cells. The enzyme required NADH as a cosubstrate and the optimal pH for the reaction was approximately 6.5. The purified enzyme also exhibited NADH diaphorase activity and its denatured molecular weight was approximately 54 kDa.     

Insecticidal effect of phthalides and furanocoumarins from Angelica acutiloba against Drosophila melanogaster

Insecticidal activity of Angelica acutiloba extract and its constituents was investigated and compared with that of rotenone. Bioassay-guided isolation of the chloroform extract of A. acutiloba against larvae of Drosophila melanogaster afforded two phthalides, (Z)-butylidenephthalide (1) and (Z)-ligustilide (2), and two furanocoumarins, xanthotoxin (3) and isopimpinellin (4). The structures of these compounds were established by spectroscopic analysis. The isolated compounds 1, 2, 3, and 4 exhibited LC(50) values of 0.94, 2.54, 3.35, and 0.82 micromol/mL of diet concentration against larvae of D. melanogaster, respectively. Against both sexes (males/females, 1:1) of adults (5-7 days old), compound 1 showed the most potent activity with a LD(50) value of 0.84 microg/adult. Compound 1 is a more active insecticide than rotenone (LD(50) = 3.68 microg/adult) and has potential as a novel insect control agent. However, compound 2 was inactive against adults. The structure-activity relationship of phthalides isolated indicated that the aromaticity appeared to play an important role in the activity of both larvae and adults. To determine the insecticide mode of action for acute adulticidal activity, acetylcholinesterase (AChE) inhibitory activity was also investigated in vitro, and the result indicated that the acute adulticidal activity of compounds 3 and 4 was due to the inhibition of AChE.     

Antidiabetic activity of red wine polyphenolic extract, ethanol, or both in streptozotocin-treated rats

A polyphenol extract from a Corbières (France) red wine (P, 200 mg/kg), ethanol (E, 1 mL/kg), or a combination of both (PE) was administered by daily gavage for 6 weeks to healthy control or streptozotocin (60 mg/kg i.v.)-induced diabetic rats (180-200 g). Treatment groups included C or D (untreated control or diabetic) and CP, CE, or CPE (treated control) or DP, DE, or DPE (treated diabetic). P treatment induced a reduction in body growth, food intake, and glycemia in both CP and DP groups. In DP, hyperglycemia was reduced when measured 1 h after daily treatment but not at sacrifice (no treatment on that day). The hyperglycemic response to the oral glucose tolerance test (OGTT) and plasma insulin at sacrifice were impaired similarly in DP and D groups. In contrast, in DE or DPE, body growth was partially restored while hyperglycemia was reduced both during treatment and at sacrifice. In addition, hyperglycemia response to OGTT was reduced and plasma insulin was higher in DE or DPE than in D animals, indicating a long-term correction of diabetes in ethanol-treated animals. Morphometric studies showed that ethanol partially reversed the enlarging effect of diabetes on the mesenteric arterial system while the polyphenolic treatment enhanced it in the absence of ethanol. In summary, our study shows that (i). a polyphenol extract from red wine ("used at a pharmacological" dose) reduces glycemia and decreases food intake and body growth in diabetic and nondiabetic animals and (ii). ethanol ("nutritional" dose) administered alone or in combination with polyphenols is able to correct the diabetic state. Some of the effects of polyphenols were masked by the effects of ethanol, notably in diabetic animals. Further studies will determine the effect of "nutritional" doses of polyphenols as well as their mechanism of action.     

Evaluation of genetic diversity and plant growth promoting activities of nitrogen-fixing bacilli isolated from rice fields in South Brazil

Several strains of bacilli, mainly species of the genera Bacillus and Paenibacillus, displaying important plant growth promoting (PGP) characteristics were isolated from seven distinct rice production zones of the Rio Grande do Sul State, Brazil. Of 296 isolates, 155 were from rhizospheric soil and 141 from bulk soil. In order to evaluate the diversity among the isolates of each bacterial population the Shannon index was used on a 70% similarity basis. Diversity indices varying from 2.27 to 5.51 were obtained. Using principal coordinate analysis (PCA) to correlate bacterial diversity with soil parameters, it was found that soil pH was the characteristic most closely related to bacilli diversity. The bacilli isolated were also analyzed for some PGP activities. Of those 296 isolates, 94 and 148 produced between 0.1 and 30 μg of indole-3-acetic acid (IAA) ml⁻¹ in vitro after 72 and 144 h of incubation, respectively. Twenty-two isolates were able to solubilize phosphate and 32 isolates produced siderophores. Paenibacillus and Bacillus genera were the most prominent groups in the rhizosphere and soil populations analyzed. Paenibacillus borealis was the most frequent species in both locations. The isolate SVPR30, identified by 16S rRNA gene sequence analysis as a strain of Bacillus sp., was chosen for in vivo greenhouse experiments and proved to be very efficient in promoting a significant increase in the roots and shoot parts of rice plants. The identification and isolation of PGP bacilli from temperate and subtropical soils, which combine the ability to fix nitrogen with the production of substances capable to promote the plant growth, could significantly increase productivity of grain crops in Brazil.