多功能地衣真菌的筛选及其复合菌剂的研制

为了从地衣真菌中筛选高效多功能菌种,研制出高效的微生物菌肥,对地衣真菌采用水解圈法初筛,再分别采用DNS法、钼锑抗比色法、平板对峙法复筛出具有高效降解纤维素、溶解无机磷、抑制病原菌活性的菌株;以不同的菌株组合研制生物菌剂,并进行盆栽试验筛选出促生活性最好的组合.从120株地衣真菌中筛选出高效降解的纤维素菌株为1905-...     

N-heterocyclic derivatives of 2,4-dihydroxybenzcarbothioamide as antimycotic agents.

N-heterocyclic derivatives of 2,4-dihydroxybenzcarbothioamide were synthesized from sulfinylbis(2,4-dihydroxybenzenethioyl) and commercially available heterocyclic amines. The composition and chemical structures were confirmed by IR, (1)H NMR, EI-MS, and elemental analysis. For the estimation of potential activity in vitro the MIC values against 15 strains of dermatophytes, yeasts, and molds were determined. The strongest fungistatic potency was found for N-5'-(3'-oxobenzfurylidyne)-2,4-dihydroxybenzcarbothioamide in relation to all tested dermatophyte strains with MIC = 0.48-0.98 microg/mL. On the basis of the spectroscopic data the influence of N-heterocyclic substitution on antimycotic activity is discussed.     

Antibacterial activity of the plant-derived compounds 23-methyl-6-O-desmethylauricepyrone and (Z,Z)-5-(trideca-4,7-dienyl)resorcinol and their synergy with antibiotics against methicillin-susceptible and -resistant Staphylococcus aureus

The present study investigated the antibacterial activity of two plant-derived compounds, 23-methyl-6-O-desmethylauricepyrone (1) and (Z,Z)-5-(trideca-4,7-dienyl)resorcinol (2), and their synergistic effects with erythromycin and gentamicin against methicillin-susceptible (MSSA) and gentamicin- and methicillin-resistant Staphylococcus aureus (MRSA). Studies of the individual antibacterial activity of each plant-derived compound and synergy experiments were carried out, by the microdilution test in agar and by the checkerboard method, respectively. Compound 1 showed minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 2 and 8 μg/mL, respectively, against both strains of S. aureus, while compound 2 exhibited anti-MSSA and anti-MRSA activity with MICs and MBCs of 4 and 8 and 2 and 8 μg/mL, respectively. Time-kill curves showed that, while compound 1 produced complete killing of both strains at 24 h from the beginning of the experiment, 2 produced the same effect in the first hour. Combinations of 1 with erythromycin or gentamicin showed a notable synergism against MSSA, which enabled the antibiotic concentration to decrease by up to 300 or 260 times, respectively. When the aminoglycoside was placed together with compound 2, only an additive effect was observed. The assayed compounds did not produce erythrocyte hemolysis or genotoxicity and they did not affect macrophage viability at the effective or higher concentrations. These results suggest that both compounds could be considered as promising antibacterial agents while compound 1 could be used in combinatory therapies with erythromycin and gentamicin.     

Purification and characterization of a corrinoid compound from Chlorella tablets as an algal health food

Vitamin B(12) content of an algal health food, Chlorella tablets (Chlorella sp.), was determined by both Lactobacillus leichmannii ATCC 7830 microbiological and intrinsic factor-chemiluminescence methods. The values of 200.9-211.6 microg/100 g dry weight determined by the chemiluminescence method were similar to the values (201.3-285.7 microg/100 g dry weight) determined by the microbiological method. A corrinoid compound was purified to homogeneity from the Chlorella tablets and characterized. The purified corrinoid compound was identified as vitamin B12, on the basis of silica gel 60 TLC, C18 reversed-phase HPLC, 1H NMR spectroscopy, and UV-Vis spectroscopy.     

selective production and characterization of levan by Bacillus subtilis (Natto) Takahashi

To meet the industrial need of an efficient microbial method for increased levan production, Bacillus subtilis (natto) Takahashi, a commercial natto starter for preparing fermented soybeans (natto), was used to produce levan. After cultivation for 21 h, 40-50 mg of levan mL(-1) was produced in medium containing 20% (w/w) sucrose, which was approximately 50% yield on available fructose. The product consisted of two fractions with different molecular masses (1794 and 11 kDa), which were easily separated by fractionation using an ethanol gradient. The products were well characterized by GPC, 13C NMR, and 1H NMR. The various sugars and concentrations, initial pH, fermentation temperature, and agitation speed affected the levan production by B. subtilis (natto) Takahashi. Takahashi strain is the most efficient levan-producing strain among all of the B. subtilis strains tested and, as previously reported, it produced the highest yield of levan in the least time (21 h) under the common cultivation condition.     

Identification of an antioxidant,ethyl protocatechuate,in peanut seed testa

The antioxidant activity and identification of the antioxidant component of peanut seed testa were investigated. The antioxidant activity of peanut seed testa was studied in the linoleic acid model system by using the ferric thiocyanate method. Among the five organic solvent extracts, the ethanolic extracts of peanut seed testa (EEPST) produced higher yields and stronger antioxidant activity than other organic solvent extracts. EEPST was separated into 17 fractions on silica gel column chromatography. Fraction 17, which showed the largest yield and significant antioxidant activity, was separated by thin-layer chromatography. Four major antioxidative subfractions were present. Subfraction 17-2 was found to be effective in preventing oxidation of linoleic acid. This subfraction was further fractionated and isolated and characterized by UV, MS, IR, and (1)H NMR techniques. The active compound was identified as ethyl protocatechuate (3,4-dihydroxybenzoic acid ethyl ester).     

杀虫活性成分6β-丙氧基苦皮藤素Ⅴ的微量合成

苦皮藤根皮粉经苯回流提取、大孔树脂层析和硅胶层析后获得苦皮藤素Ⅴ。以正丙醇和苦皮藤素Ⅴ为原料,建立了基于无水碘代反应和威廉姆逊反应的6β-丙氧基苦皮藤素Ⅴ的微量合成方法,反应总收率约为17%。最终产物以HRMS、1H NMR和13C NMR确认为6β-丙氧基苦皮藤素Ⅴ。HPLC分析表明,该产物纯度大于98%。该方法为杀虫活性成分6β-丙氧基苦皮藤素Ⅴ的放射性同位素标记合成奠定了基础。     

Identification and structure elucidation of a p-phenoxybenzaldehyde in bamboo shoots by HPLC-ESI/MS/MS and NMR

In this study, a derivative of p-phenoxybenzaldehyde in bamboo shoots was investigated. Bamboo shoots were ground and extracted with water, and an aqueous suspension was purified by SPE using Oasis HLB cartridges. After the SPE procedure, the analytes were analyzed by HPLC with refractive index detection (HPLC-RI). In the HPLC-RI analysis for sucralose, a putative sucralose was detected. In the subsequent HPLC-PDA analysis, the suspicious peak showed a unique UV absorption spectrum with the maximum wavelength at 285 nm indicating the existence of an aromatic ring. The contents of the unknown compound in bamboo shoot products ranged from 0.01 to 0.15 mg/g. The identity of the unknown compound was further confirmed by HPLC-ESI/MS/MS. The molecular weight of the unknown compound was determined to be 244. The chemical structure of the unknown compound was elucidated on the basis of NMR spectroscopic analyses ((1)H, (13)C, DEPT, COSY, HMQC, and HMBC). Finally, the structure of the unknown compound was characterized as 4-(4-dihydroxymethylphenoxy)benzaldehyde.     

Isolation and identification of molecular species of phosphatidylcholine and lysophosphatidylcholine from jojoba seed meal (Simmondsia chinensis)

A mixture of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC) has been isolated by column chromatography from a jojoba meal (Simmondsia chinensis) extract. The molecular species of both classes could be separated and isolated by C18 reversed phase HPLC. The two major compounds were identified by 1D and 2D (1)H and (13)C NMR, by MS, and by GC-MS as 1-oleoyl-3-lysophosphatidylcholine and 1,2-dioleoyl-3-phosphatidylcholine. Eight other molecular species of LPC and four other molecular species of PC could be assigned by comparison of the mass spectra of the isolated compounds with the spectra of the two major compounds. Complete characterization of the individual molecular species was achieved by GC and GC-MS analysis of the fatty acyl composition from the isolated compounds. The PC/LPC proportion in the phospholipid mixture from three different samples is 1.6 +/- 0.1. LPC is considered to be an important bioactive compound; the results of this study suggest further research for the evaluation of potential health benefits of jojoba meal phospholipids.     

Isolation and Caenorhabditis elegans lifespan assay of flavonoids from onion

The main flavonoids were isolated from three selected onion cultivars. Three phenolic compounds were obtained by reverse-phase HPLC, and their structures were elucidated by multiple NMR measurements. There were two known compounds, quercetin and quercetin 3'-O-β-D-glucopyranoside (Q3'G), and one novel compound, quercetin 3-O-β-D-glucopyranoside-(4→1)-β-d-glucopyranoside (Q3M), which was identified in onion for the first time. These flavonoids were found to be more abundant in the onion peel than in the flesh or core. Their antioxidative activities were tested using the DPPH method, and their antiaging activities were evaluated using a Caenorhabditis elegans lifespan assay. No direct correlation was found between antioxidative activity and antiaging activity. Quercetin showed the highest antioxidative activity, whereas Q3M showed the strongest antiaging activity among these flavonoids, which might be related to its high hydrophilicity.     

Molecular characterization around a glassy transition of starch using (1)H cross-relaxation nuclear magnetic resonance

The aim of this work was to characterize the glassy-rubbery transition in starch gels using molecular (NMR) techniques. Proton cross-relaxation ((1)H CR) NMR spectra of gelatinized starch ( approximately 50% mc) were obtained by cooling stepwise from 20 to -30 degrees C. A significant line broadening was observed in the CR spectra between 0 and -10 degrees C. Deconvolution of the spectra into its component curves (broad and narrow) yielded a peak amplitude, width at half-height, and peak area for each curve. Between 0 and -10 degrees C (temperatures around T(g)), a significant line width change in the broad component (rigid solid) was apparent. These observed qualitative changes may be evidence of a glassy-rubbery transition at a molecular (short-range) level which are strengthened by a similar transition temperature range found previously with (13)C CP-MAS and DMA tan delta(T) measurements. However, the increase in the relative quantity of rigid protons observed by (1)H CR NMR spectra could also be attributed to ice. The (1)H CR NMR method showed its potential application for probing solid components in gels using a simple and economical NMR spectrometer, without the need for a solid-state instrument.     

Natural fungicides from Ruta graveolens L. leaves,including a new quinolone alkaloid

Bioassay-directed isolation of antifungal compounds from an ethyl acetate extract of Ruta graveolens leaves yielded two furanocoumarins, one quinoline alkaloid, and four quinolone alkaloids, including a novel compound, 1-methyl-2-[6'-(3' ',4' '-methylenedioxyphenyl)hexyl]-4-quinolone. The (1)H and (13)C NMR assignments of the new compound are reported. Antifungal activities of the isolated compounds, together with 7-hydroxycoumarin, 4-hydroxycoumarin, and 7-methoxycoumarin, which are known to occur in Rutaceae species, were evaluated by bioautography and microbioassay. Four of the alkaloids had moderate activity against Colletotrichum species, including a benomyl-resistant C. acutatum. These compounds and the furanocoumarins 5- and 8-methoxypsoralen had moderate activity against Fusarium oxysporum. The novel quinolone alkaloid was highly active against Botrytis cinerea. Phomopsis species were much more sensitive to most of the compounds, with P. viticola being highly sensitive to all of the compounds.     

Isolation and characterization of a new compound from Prunus mume fruit that inhibits cancer cells

An active compound that inhibits cancer cells was isolated from the fruit of Prunus mume, and its structure and in vitro activities were characterized. The n-hexane fraction obtained from methanol extracts exhibited the strongest inhibitory effect on the growth of cancer cells. From the n-hexane fraction, a new compound named B-1 was purified through preparative thin-layer chromatography, ODS column chromatography, and reverse phase high-performance liquid chromatography and its structure was analyzed by fast atom bombardment mass spectrometry and 1H and 13C NMR. The molecular formula of B-1 was C19H22O6 {2-hydroxy-1-[(7-hydroxy-2-oxo-2H-chromen-6-yl)methyl]-2-methylpropyl-(2Z)-3-methyl-but-e-enoate:prunate}, and the IC50 value was in the range of 39-58 microg/mL in descending order of the cancer cell lines Hep-2, SW-156, HEC-1-B, and SK-OV-3. B-1 exhibited 81-96% inhibition at a concentration level of 100 microg/mL against all cells, based on an 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. However, B-1 showed little effect against normal cells with only 23% or less growth inhibition at 100 microg/mL. Thus, B-1 has a highly specific inhibitory effect against cancer cells but little effect against normal cells. When the cancer cell lines Hep-2 and SK-OV-3 were incubated with B-1 for 72 h, most of the tested cells suffered strong growth inhibition. The compound has the potential to be developed as a nutraceutical.     

Characterization of two unknown compounds in methanol extracts of rosemary oil

In this study, two unknown compounds in rosemary oil, containing 3% carnosic acid and 0.3% carnosol, were identified and characterized. After methanol extraction, purification, and analysis by reversed-phase HPLC and LC-MS, a recovery of 92% (+/-8%) of carnosic acid was obtained, but no carnosol was found. However, two unknown compounds with a molecular weight of 330.2 and 302.2 were consistently detected. From additional LC-MS-MS, (1)H NMR, and elemental analyses, it became clear that the first compound (M(w) = 330.2) could not be carnosol. It was hypothesized that it originated from the breakdown of the intramolecular bond of carnosol, followed by the addition of a water molecule. Possibly, an unsaturated double bond was formed after dehydration. Assuming that this compound was an intermediate in the conversion to rosmanol, the second unknown compound (M(w) = 302.2) may have resulted from the breakdown of the intramolecular bond of rosmanol. Similarly, an unsaturated double bond may have been formed. After splitting off carbon oxide, a detectable molecule with a molecular weight of 302.2 was observed.     

Isolation, antifungal activity, and structure elucidation of the glutarimide antibiotic, streptimidone, produced by Micromonospora coerulea.

The antibiotic Ao58A,which showed strong antifungal activity against some plant pathogenic fungi, was purified from the culture broth and mycelial mats of Micromonospora coerulea strain Ao58 using various chromatographic procedures. The molecular formula of the antibiotic Ao58A was deduced to be C(16)H(23)NO(4) (M + H, m/z 294.1707) by high-resolution FAB mass spectroscopy. Analyses of (1)H NMR, (13)C NMR, and 2D NMR spectral data revealed that the antibiotic Ao58A is the glutarimide antibiotic streptimidone, 4-(2-hydroxy-5, 7-dimethyl-4-oxo-6,8-nonadienyl)-2,6-piperidinedione. The antibiotic Ao58A was very effective in inhibiting growth of Phytophthora capsici,Didymella bryoniae, Magnaporthe grisea, and Botrytis cinerea in the range approximately 3-10 microg mL(-)(1) of MICs. In vivo evaluation of the antibiotic Ao58A under greenhouse condition showed strong control efficacies against the development of P. capsici, B. cinerea, and M. grisea on pepper, cucumber, and rice plants, respectively. The antibiotic Ao58A was equally as effective as metalaxyl, vinclozolin, and tricyclazole in the control of these plant diseases. However, it did not show any phytotoxicity on the plants even when treated with 500 microg mL(-)(1).     

New bioactive biomaterials based on quaternized chitosan

Chitosan was chemically modified to produce quaternary ammonium salts in order to improve its antimicrobial activity and physicochemical properties. Quaternization of N-alkyl chitosan derivatives was carried out using alkyl iodide to elaborate water-soluble cationic polyelectrolytes ( N, N, N-trimethylchitosan, TMC). TMC was characterized by (1)H NMR spectroscopy; the quaternization degree was determined from (1)H NMR spectra and by titration of iodide ion. The antibacterial activity of hydroxypropylcellulose (HPC) films or coatings associated with chitosan or TMC as biocide was evaluated against the growth of Listeria monocytogenes and Salmonella typhimurium. The HPC-chitosan and HPC-TMC coatings exhibited a total inhibition on solid medium of both bacterial strains. Experiments conducted in liquid medium showed that the inhibitory activity against the growth of Listeria innocua was improved after chemical modification. Moreover, physicochemical properties of films were evaluated to determine their potential for food applications. The addition of the antibacterial agents showed a significant impact on the moisture barrier and mechanical properties of HPC films.     

Abundance and reactivity of dibenzodioxocins in softwood lignin

To define the abundance and comprehend the reactivity of dibenzodioxocins in lignin, model compound studies, specific degradation experiments on milled wood lignin, and molecular modeling calculations have been performed. Quantitative (31)P NMR measurements of the increase of biphenolic hydroxyl groups formed after a series of alkaline degradations in the presence of hydrosulfide anions (kraft conditions) showed the presence of 3.7 dibenzodioxocin rings/100 C9 units in milled wood lignin. The DFRC degradation protocol (Derivatization Followed by Reductive Cleavage) was chosen as an independent means to estimate their abundance. Initial experiments with a dibenzodioxocin model compound, trans-6,7-dihydro-7-(4-hydroxy-3-methoxyphenyl)-4,9-dimethoxy-2,11-dipropyldibenzo[e,g][1,4]dioxocin-6-ylmethanol, showed that it is not cleaved under DFRC conditions, but rather it isomerizes into a cyclic oxepine structure. Steric effects precluded this isomerization from occurring when DFRC was applied to milled wood lignin. Instead, monoacetylated biphenolic moieties were released and quantified by (31)P NMR, at 4.3 dibenzodioxocin rings/100 C9 units. The dibenzodioxocin content in residual lignins isolated from kraft pulps delignified to various degrees showed that during pulp delignification, the initial rate of dibenzodioxocin removal was considerably greater than the cleavage rate of arylglycerol-beta-aryl ether bonds. The activation energy for the degradation of dibenzodioxocins under kraft conditions in milled wood lignin was 96 +/- 9 kJ/mol, similar to that of arylglycerol-beta-aryl ether bond cleavage.     

Antimutagenic activity of isoflavone from Pueraria lobata

A methanol extract from Pueraria lobata showed a suppressive effect on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide). The methanol extract from P. lobata was re-extracted with hexane, dichloromethane, ethyl acetate, butanol, and water, respectively. A suppressive compound in the dichloromethane and ethyl acetate extract fractions was isolated by SiO(2) column chromatography and identified as tectorigenin (1) by EI-MS and (1)H and (13)C NMR spectroscopy. Compound 1 and its methylated derivative [7,4'-di-O-methyltectorigenin (2)] had the suppressive effects on umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK1002 against furylfuramide, 4-nitroquinoline-1-oxide, N-methyl-N'-nitrosoguanidine, and activated Trp-P-1, which do not require live metabolic activation by S9. These compounds also showed suppression of SOS-inducing activity against Trp-P-1 and AfB(1), which requires liver metabolizing enzymes. In addition to the antimutagenic activities of these compounds against furylfuramide, Trp-P-1 and activated Trp-P-1 were also assayed by an Ames test using S. typhimurium TA100.     

Identification of potent odorants formed by autoxidation of arachidonic acid: structure elucidation and synthesis of (E,Z,Z)-2,4,7-tridecatrienal.

The aroma composition of autoxidized arachidonic acid was characterized by aroma extract dilution analysis. The most potent odorant was trans-4,5-epoxy-(E)-2-decenal followed by 1-octen-3-one, (E,Z)-2,4-decadienal, (E,Z,Z)-2,4,7-tridecatrienal, (E,E)-2,4-decadienal, and hexanal. (E,Z,Z)-2,4,7-Tridecatrienal was unequivocally identified by mass spectrometry and nuclear magnetic resonance (NMR) data. The stereochemistry of its extended double-bond system was elucidated on the basis of NMR measurements. The target compound was synthesized in four steps starting with bromination of 2-octyn-1-ol, followed by copper-catalyzed coupling of the bromide with ethylmagnesium bromide and (E)-2-penten-4-yn-1-ol. Partial hydrogenation of the resulting C(13)-compound with triple bonds in the positions C-4 and C-7 gave rise to (E,Z,Z)-2,4,7-tridecatrien-1-ol, which was finally oxidized to the target compound. It exhibits a typical egg-white-like, marine-like odor at low concentrations, and an intense orange-citrus, animal-like odor at higher concentrations. Its odor threshold was estimated by gas chromatography-olfactometry to be 0.07 ng/L air, which is of the same order of magnitude as that reported for 1-octen-3-one and (E,E)-2,4-decadienal.