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1.
The use of in vitro trout hepatocyte cultures is shown to provide a simple and effective way to screen plant and food products for oestrogenic activity. The relative oestrogenic activities of 0.1 g each of extracts of phytosterol, soy isoflavone, red clover, kudzu and soybean extracts were determined using this assay and found to be equivalent to 212, 1, 3.2, 132 and 1025 nM of 17beta-estradiol, respectively. Controls were performed on soybean and kudzu extracts using specific ELISAs for isoflavones and these confirmed the validity of the cell culture assay. The method described offers an advantage over current methods in that it can detect increased oestrogenic activity that may occur as a result of metabolic activation of pre- or pro-oestrogens liver cells.  相似文献   

2.
We determined the distribution of lecithin molecular species between vesicles and mixed micelles in cholesterol super-saturated model biles (molar taurocholate-lecithin-cholesterol ratio 67:23:10, 3 g/dl, 0.15 M NaCl, pH approximately 6-7) that contained equimolar synthetic lecithin mixtures or egg yolk or soybean lecithins. After apparent equilibration (48 h), biles were fractionated by Superose 6 gel filtration chromatography at 20 degrees C, and lecithin molecular species in the vesicle and mixed micellar fractions were quantified as benzoyl diacylglycerides by high performance liquid chromatography. With binary lecithin mixtures, vesicles were enriched with lecithins containing the most saturated sn-1 or sn-2 chains by as much as 2.4-fold whereas mixed micelles were enriched in the more unsaturated lecithins. Vesicles isolated from model biles composed of egg yolk (primarily sn-1 16:0 and 18:0 acyl chains) or soy bean (mixed saturated and unsaturated sn-1 acyl chains) lecithins were selectively enriched (6.5-76%) in lecithins with saturated sn-1 acyl chains whereas mixed micelles were enriched with lecithins composed of either sn-1 18:1, 18:2, and 18:3 unsaturated or sn-2 20:4, 22:4, and 22:6 polyunsaturated chains. Gel filtration, lipid analysis, and quasielastic light scattering revealed that apparent micellar cholesterol solubilities and metastable vesicle cholesterol/lecithin molar ratios were as much as 60% and 100% higher, respectively, in biles composed of unsaturated lecithins. Acyl chain packing constraints imposed by distinctly different particle geometries most likely explain the asymmetric distribution of lecithin molecular species between vesicles and mixed micelles in model bile as well as the variations in apparent micellar cholesterol solubilities and vesicle cholesterol/lecithin molar ratios.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
Antimicrobial activity of essential oils and other plant extracts   总被引:16,自引:0,他引:16  
The antimicrobial activity of plant oils and extracts has been recognized for many years. However, few investigations have compared large numbers of oils and extracts using methods that are directly comparable. In the present study, 52 plant oils and extracts were investigated for activity against Acinetobacter baumanii, Aeromonas veronii biogroup sobria, Candida albicans, Enterococcus faecalis, Escherichia col, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhimurium, Serratia marcescens and Staphylococcus aureus, using an agar dilution method. Lemongrass, oregano and bay inhibited all organisms at concentrations of < or = 2.0% (v/v). Six oils did not inhibit any organisms at the highest concentration, which was 2.0% (v/v) oil for apricot kernel, evening primrose, macadamia, pumpkin, sage and sweet almond. Variable activity was recorded for the remaining oils. Twenty of the plant oils and extracts were investigated, using a broth microdilution method, for activity against C. albicans, Staph. aureus and E. coli. The lowest minimum inhibitory concentrations were 0.03% (v/v) thyme oil against C. albicans and E. coli and 0.008% (v/v) vetiver oil against Staph. aureus. These results support the notion that plant essential oils and extracts may have a role as pharmaceuticals and preservatives.  相似文献   

4.
A soybean seed urease-null produces urease in cell culture   总被引:9,自引:7,他引:2       下载免费PDF全文
Itachi, a soybean (Glycine max [L.] Merr.) variety with 0.2% normal seed urease activity, was recovered from a screen of 6,000 entries in the United States Department of Agriculture soybean germplasm collection. No urease antigen in Itachi seed extracts was detected by double diffusion or by rocket immunoelectrophoresis. Native gels stained for protein or ureolytic activity revealed no detectable urease holoenzyme. An anti-urease antibody affinity column was used to remove all detectable urease activity and antigen from `wild type' (cv. Prize) seed extracts. Affinity column effluent and nonchromatographed Itachi extracts both lack a species which comigrates with purified urease subunits in sodium dodecylsulfate polyacrylamide gels. Inability to detect urease antigen or urease protein suggests that during development of Itachi seeds there is no synthesis of urease protein or that, at most, its synthesis is 0.2% of wild type (Prize).  相似文献   

5.
The effect of industrial carbon sources on phospholipid transfer protein production was investigated. Phospholipid fractions of different composition were prepared from various plant oils (i.e., soybean, rapeseed, and sunflower) according to the Lucas Meyer extraction and purification process. The effect of these fractions on phospholipid transfer protein activity of cell extracts from Aspergillus oryzae grown on medium containing these phospholipids as sole carbon source was studied. It was shown that phospholipid transfer activity was markedly increased by extracts containing a particular phospholipid composition. However, this stimulation depends mainly upon the phospholipid composition of the fraction used as fermentation substrate. Fractions enriched mainly in phosphatidylinositol (Epikuron 110), at the expense of phosphatidylcholine, were the most efficient sources for phospholipid transfer protein production by A. oryzae. Maximal phospholipid transfer activity, as well as biomass production, were increased 4.1- and 9.7-fold, respectively, when cultures were supplemented with Epikuron 110 prepared from sunflower lecithin, as compared to glucose-control cultures.  相似文献   

6.
Biodiesel is an alternative diesel fuel made from renewable biological resources. During the process of biodiesel production, lipase-catalyzed transesterification is a crucial step. However, current techniques using methanol as acyl acceptor have lower enzymatic activity; this limits the application of such techniques in large-scale biodiesel production. Furthermore, the lipid feedstock of currently available techniques is limited. In this paper, the technique of lipase-catalyzed transesterification of five different oils for biodiesel production with methyl acetate as acyl acceptor was investigated, and the transesterification reaction conditions were optimized. The operation stability of lipase under the obtained optimal conditions was further examined. The results showed that under optimal transesterification conditions, both plant oils and animal fats led to high yields of methyl ester: cotton-seed oil, 98%; rapeseed oil, 95%; soybean oil, 91%; tea-seed oil, 92%; and lard, 95%. Crude and refined cottonseed oil or lard made no significant difference in yields of methyl ester. No loss of enzymatic activity was detected for lipase after being repeatedly used for 40 cycles (ca. 800 h), which indicates that the operational stability of lipase was fairly good under these conditions. Our results suggest that cotton-seed oil, rape-seed oil and lard might substitute soybean oil as suitable lipid feedstock for biodiesel production. Our results also show that our technique is fit for various lipid feedstocks both from plants and animals, and presents a very promising way for the large-scale biodiesel production.  相似文献   

7.
Fibroblast extracts from 20 individuals with homocystinuria due to cystathionine beta-synthase deficiency were analyzed for the presence of immunoreactive synthase antigen as cross-reacting material (CRM). CRM was quantitated by competitive and direct immunotitration using rabbit antiserum against homogeneous human liver synthase. The lower limit of sensitivity for detection of CRM was 1.5% of the amount of synthase antigen in control extracts. Each of 14 mutant extracts with detectable synthase activity had detectable CRM ranging from 5% to 100% of the amount found in control extracts. No statistically significant correlation was observed between the percent residual activity and the percent CRM. Of six mutant extracts without measurable catalytic activity, three had no detectable CRM, while three had 13%, 17%, and 26% CRM, respectively. These results extend our information about the biochemical heterogeneity previously found in synthase deficiency, and emphasize that such deficiency is caused by a wide array of mutations affecting the structural locus for cystathionine beta-synthase.  相似文献   

8.
The cotyledons of soybean begin to develop photosynthetic capacity shortly after emergence. The cotyledons develop nitrate reductase (NR) activity in parallel with an increase in chlorophyll and a decrease in protein. In crude extracts of 5- to 8-day-old cotyledons, NR activity is greatest with NADH as electron donor. In extracts of older cotyledons, NR activity is greatest with NADPH. Blue-Sepharose was used to purify and separate the NR activities into two fractions. When the blue-Sepharose was eluted with NADPH, NR activity was obtained which was most active with NADPH as electron donor. Assays of the NADPH-eluted NR with different concentrations of nitrate revealed that the highest activity was obtained in 80 millimolar KNO3. Thus, this fraction has properties similar to the low nitrate affinity NAD(P)H:NR of soybean leaves. When 5- to 8-day-old cotyledons were extracted and purified, further elution of the blue-Sepharose with KNO3, subsequent to the NADPH elution, yielded an NR fraction most active with NADH. Assays of this fraction with different nitrate concentrations revealed that this NR had a higher nitrate affinity and was similar to the NADH:NR of soybean leaves. The KNO3-eluted NR fraction which was purified from the extracts of 9- to 14-day-old cotyledons, was most active with NADPH. The analysis of these fractions prepared from the extracts of older cotyledons indicated that residual NAD(P)H:NR contaminated the NADH:NR. Despite this complication, the pattern of development of the purified NR fractions was consistent with the changes observed in the crude extract NR activities. It was concluded that NADH:NR was most active in young cotyledons and that as the cotyledons aged the NAD(P)H:NR became more active.  相似文献   

9.
Biochemical, electrophoretic and immunological studies were made among peroxisomal enzymes in three organs of soybean [Glycine max (L.) Merr. cv. Centennial] to compare the enzyme distribution and characteristics of specialized peroxisomes in one species. Leaves, nodules and etiolated cotyledons were compared with regard to several enzymes localized solely in their peroxisomes: catalase (EC 1.11.1.6), malate synthase (EC 4.1.3.2), glycolate oxidase (EC 1.1.3.1), and urate oxidase (EC 1.7.3.3). Catalase activity was found in all tissue extracts. Electrophoresis on native polyacrylamide gels indicated that leaf catalase migrated more anodally than nodule or cotyledon catalase as shown by both activity staining and Western blotting. Malate synthase activity and immunologically detectable protein were present only in the cotyledon extracts. Western blots of denaturing (lithium dodecyl sulfate) gels probed with anti-cotton malate synthase antiserum, reveal a single subunit of 63 kDa in both cotton and soybean cotyledons. Glycolic acid oxidase activity was present in all three organs, but ca 20-fold lower (per mg protein) in both nodule and cotyledon extracts compared to leaf extracts. Electrophoresis followed by activity staining on native gels indicated one enzyme form with the same mobility in nodule, cotyledon and leaf preparations. Urate oxidase activity was found in nodule extracts only. Native gel electrophoresis showed a single band of activity. Novel electrophoretic systems had to be developed to resolve the urate oxidase and glycolate oxidase activities; both of these enzymes moved cathodally in the gel system employed while most other proteins moved anodally. This multifaceted study of enzymes located within three specialized types of peroxisomes in a single species has not been undertaken previously, and the results indicate that previous comparisons between the enzyme content of specialized peroxisomes from different organisms are mostly consistent with that for a single species, soybean.  相似文献   

10.

Background

The allergenicity of Ricinus communis L. (castor bean, Euphorbiaceae) is associated with components of its seeds and pollen. Castor bean allergy has been described not only in laboratory workers, but also in personnel working in oil processing mills, fertilizer retail, the upholstery industry and other industrial fields. In the present study, we describe the critical amino acids in the IgE-binding epitopes in Ric c 1 and Ric c 3, two major allergens of R. communis. In addition, we also investigate the cross-reactivity between castor bean and some air and food allergen extracts commonly used in allergy diagnosis.

Methodology/Principal Findings

The IgE reactivity of human sera from atopic patients was screened by immune-dot blot against castor bean allergens. Allergenic activity was evaluated in vitro using a rat mast cell activation assay and by ELISA. Cross-reactivity was observed between castor bean allergens and extracts from shrimp, fish, gluten, wheat, soybean, peanut, corn, house dust, tobacco and airborne fungal allergens. We observed that treatment of rat and human sera (from atopic patients) with glutamic acid reduced the IgE-epitope interaction.

Conclusions/Significance

The identification of glutamic acid residues with critical roles in IgE-binding to Ric c 3 and Ric c 1 support the potential use of free amino acids in allergy treatment.  相似文献   

11.
以无水乙醇为溶剂从雷公藤根皮中提取有效成分,用高效液相色谱法分析雷公藤粗提物中甲索含量,并将雷公藤粗提物配成5%的乳油,用浸叶法和药膜法测定小菜蛾二龄幼虫、烟粉虱成虫以及无翅成蚜的室内毒力,并以几种杀虫剂作为对比。结果表明:该批雷公藤粗提物中甲素含量为0.0012%;5%雷公藤粗提物乳油对小菜蛾二龄幼虫、烟粉虱成虫以及无翅成蚜具有一定的生物活性,但与其他几种常用杀虫剂相比活性较低,还需对其进一步精制和提纯。  相似文献   

12.
Coffee oil as a potential feedstock for biodiesel production   总被引:2,自引:1,他引:1  
A preliminary evaluation of the feasibility of producing biodiesel using oil extracted from defective coffee beans was conducted as an alternative means of utilizing these beans instead of roasting for consumption of beverage with depreciated quality. Direct transesterifications of triglycerides from refined soybean oil (reference) and from oils extracted from healthy and defective coffee beans were performed. Type of alcohol employed and time were the reaction parameters studied. Sodium methoxide was used as alkaline catalyst. There was optimal phase separation after reactions using both soybean and healthy coffee beans oils when methanol was used. This was not observed when using the oil from defective beans which required further processing to obtain purified alkyl esters. Nevertheless, coffee oil was demonstrated to be a potential feedstock for biodiesel production, both from healthy and defective beans, since the corresponding oils were successfully converted to fatty acid methyl and ethyl esters.  相似文献   

13.
Summary The effect of soy sauce oil and various other oils on protease production by Aspergillus oryzae NISL 1913 was studied in chemostat cultures (dilution rate=0.02 h–1). Soy sauce oil was consumed as a carbon source by the cells and also accelerated protease production. When soy sauce oil was used as sole carbon source, the specific protease production rate was 2.89 protease units·(mg dry weight of mycelium)–1·h–1, which was threefold higher than that with starch. The specific protease production rate with linoleic acid, oleic acid, Tween 80 and soybean oil exhibited similar values to that with soy sauce oil but the fatty acids with carbon chains shorter than six, such as caproic acid and acetic acid, did not stimulate protease production. The oils did not cause an increase in other exocellular enzymes such as -amylase, indicating that the protease production was selectively stimulated by the oils. Offprint requests to: Y. Fukushima  相似文献   

14.
Isolation and Analysis of Molds from Soy Sauce Koji in Thailand   总被引:5,自引:3,他引:2       下载免费PDF全文
Five different isolates of Aspergillus and one of Mucor were compared with a Japanese commercial strain of Aspergillus oryzae for proteolytic activity on wheat bran substrate. One isolate of Aspergillus with superior protease production, identified as Aspergillus flavus var. columnaris, showed no detectable aflatoxin production on glutinous rice or soybean substrate. Preliminary tests using this fungus as a koji mold in a traditionally operated factory resulted in a soy sauce superior in quality to that usually produced.  相似文献   

15.
A 4-year old boy died of diffuse disseminated sclerosis (DDS) of the brain and was found to have also pseudoarylsulfatase A deficiency (PASAD) with about 20% residual arylsulfatase A (ASA) and cerebroside sulfatase (CS) activity. The reexamination of lipids did not show any sulfatide accumulation in the patient's organ extracts. Although the residual CS activity in the patient's extracts was clearly demonstrable only after partial purification, it was concluded that this activity protects organ tissues from sulfatide accumulation in PASAD, since in sulfatide lipidosis (metachromatic leukodystrophy, MLD) no residual CS activity was detectable. The study of residual ASA activity in the patient's fibroblasts by gel electrofocusing resulted in an almost normal enzyme microheterogeneity. However, the detailed study of the brain galactolipids in the patient revealed an elevated ratio of sulfatide/galactocerebroside content, despite the decrease of both lipids. In tissues of other patients with severe demyelinating diseases different from DDS and MLD, this galactolipid ratio was also found to be increased, especially in three patients with adrenoleukodystrophy. A general mechanism of this anomaly in severe demyelination is considered.  相似文献   

16.
To identify conserved immunoglobulin E (IgE)-binding epitopes among legume glycinins, we utilized recombinant soybean G2a and G2a-derived polypeptide fragments. All of these fusion polypeptides bound IgE, and the C-terminal 94-residue fragment appeared to bind more IgE. Using synthetic peptides we identified S219-N233 (S(219)GFAPEFLKEAFGVN(233)) as the dominant IgE-binding epitope. Alanine scanning of this epitope indicated that six amino acids (E224, F225, L226, F230, G231, and V232) contributed most to IgE binding. Among these amino acids, only G231 of soybean G2a is not conserved in soybean G1a (S234) and peanut Ara h 3 (Q256). Synthetic peptides corresponding to the equivalent regions in G1a and Ara h 3 bound IgE in the order Ara h 3>/=soybean G2a>soybean G1a. This sequence represents a new IgE-binding epitope that occurs in a highly conserved region present in legume glycinins. Such IgE-binding sites could provide a molecular explanation for the IgE cross-reactivity observed between soybean and peanut proteins.  相似文献   

17.
The activity of two purified lysolecithin-hydrolyzing enzymes on homologous series of synthetic lecithins containing two identical fatty acyl chains and of 1-acyl-lysolecithins has been measured as a function of substrate concentration. In general, enzymatic activity toward lecithins decreased with increasing chain length. Maximal hydrolysis rates for the lysolecithin series were measured with 1-dodecanoyllysolecithin. In this series increased affinities for substrates with increasing acyl-chain length was noticed. In the substrate concentration versus enzymatic velocity curves no breaks were observed at the critical micelle concentration of the various substrates. The initial site of attack during hydrolysis of short-chain lecithins was determined using 1-octanoyl-2pentanoyl-lecithin, 1-hexanoyl-2-hexyllecithin and 1 -hexyl-2-hexanoyllecithin. Both enzymes exhibited a pronounced preference for hydrolysis of the acyl ester bond at the 1-position. Especially the enzyme from beef pancreas seems to be suitable for the enzymatic preparation of 2-acyl lysolecithins from the corresponding short-chain lecithins.  相似文献   

18.
Root nodules were harvested from chamber-grown soybean (Glycine max L. Merrill cv Woodworth) plants throughout development. Apparent nitrogenase activity (acetylene reduction) peaked before seeds began to develop, but a significant amount of activity remained as the seeds matured. Nodule senescence was defined as the period in which residual nitrogenase activity was lost. During this time, soluble protein and leghemoglobin levels in the host cell cytosol decreased, and proteolytic activity against azocasein increased. Degradative changes were not detected in bacteroids during nodule senescence. Total soluble bacteroid protein per gram of nodule remained constant, and an increase in proteolytic activity in bacteroid extracts was not observed. These results are consistent with the view that soybean nodule bacteroids are capable of redifferentiation into free-living bacteria upon deterioration of the legume-rhizobia symbiosis.  相似文献   

19.
Choi EM  Suh KS  Kim YS  Choue RW  Koo SJ 《Phytochemistry》2001,56(7):733-739
To investigate the bioactivities of soybean, which act on bone metabolism, we studied the effect of a soybean ethanol extract on the activity of osteoblast MC3T3-E1 cells. Soy extract (0.01-0.1 g/l) dose-dependently increased survival (P<0.05) and DNA synthesis (P<0.05) of MC3T3-E1 cells. In addition, soy extract (0.05 g/l) increased alkaline phosphatase activity (P<0.05) and collagen synthesis (P<0.05) of MC3T3-E1 cells. Moreover, the anti-estrogen tamoxifen eliminated the stimulation of MC3T3-E1 cells on the proliferation, ALP activity and collagen synthesis by soy extract, indicating that the main action of the soy extract on osteoblastic MC3T3-E1 cells is similar to that of estrogen effects. Treatment with soy extract prevented apoptosis, as assessed by a one-step sandwich immunoassay and DNA gel electrophoresis studies. This effect may be associated with the activation of the estrogen receptor, since we observed soy extract-mediated survival against apoptosis was blocked by the estrogen receptor antagonist tamoxifen in cells, further supporting a receptor-mediated mechanism of cell survival. These results suggest that osteoblast function is promoted by soy extract and that the estrogen receptor is involved in the response, thereby playing an important role in bone remodeling. In conclusion, soy extract has a direct stimulatory effect on bone formation in cultured osteoblastic cell in vitro. Presumably, dietary soy products are useful in the prevention of osteoporosis.  相似文献   

20.
Reactivation of the lysolecithin-induced inhibition of the electrontransport in spinach chloroplasts was investigated after theaddition of various molecular species of lecithin. The additionof lecithins consisting of unsaturated fatty acids to a chloroplastsuspension that previously had been incubated with lysolecithin,restored the activity of electron transport from water to ferricyanideto the level of the activity in untreated chloroplasts; andthe activity of the transport from water to dichlorophenolindophenolalso was partially restored. No reactivation of electron flowfrom water to NADP or from reduced dichlorophenolindophenolto methyl viologen was observed with any form of lecithin. Theeffect of molecular form of lecithin on the reactivation offerricyanide photoreduction in lysolecithin-incubated chloroplastswas dilinoleoyl > soybean > dioleoyl > distearoyl =dipalmitoyl lecithin. No reactivation of the Hill reaction wasobserved on the addition of dimyristoyl lecithin. The mechanismof lecithin-induced reactivation is discussed. (Received May 23, 1979; )  相似文献   

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