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1.
The protein and oil contents and the activity of proteinase inhibitors in six varieties of soybean have been studied. It has been found that the specific amidase activity of trypsin inhibitors ranges from 170 to 320 nominal units. Electrophoretic results indicates the presence in the water-soluble fraction of seven or eight components possessing inhibitor activity in relation to trypsin and chymotrypsin. 相似文献
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This review outlines known examples of the three-dimensional structures of protein proteinase inhibitors from plants. Three families of enzymes, serine proteinases, carboxypeptidases and cysteine proteinases, are targeted by at least a dozen inhibitor families, with the majority of them adopting the standard mechanism of inhibition towards the serine proteinases. All of the inhibitors discussed maintain compact and stable inhibitory domains that bind to the active site of their target proteinases and prevent access to the substrate molecules. One interesting highlight is the knottin group. Three separate inhibitor families utilize the overall knottin fold in a different way. This fold can accommodate extensive sequence variation and for each of the squash, Mirabilis and Potato carboxypeptidase families, the proteinase-binding residues are found at a different location. Plants have also evolved additional strategies to regulate proteinase activity, such as linking inhibitory domains and targeting multiple enzymes at once. The structural aspects of these strategies are discussed in the review. 相似文献
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Clayton Antunes Martin Jesuí Vergílio Visentainer Cláudio Celestino de Oliveira Makoto Matsushita Nilson Evelázio de Souza 《Analytical sciences》2006,22(4):631-633
This study examined the concentration (mg/g) of trans polyunsaturated fatty acid (TPFA) in five soybean oil brands by gas-liquid chromatography. Tricosanoic acid methyl ester was used as the internal standard. All samples analyzed presented trans 18:2 fatty and trans 18:3 acids in detectable amounts. The concentration of TPFA ranged from 5.8 to 30.2 mg/g, with a mean concentration value of 18.4 mg/g. Trans 18:3 fatty acids had the highest TPFA group concentrations, which ranged from 3.9 to 16.3 mg/g. The main isomer of this group presented the 9c, 12c, 15t configuration. For trans 18:2 fatty acids, concentrations ranged from 1.9 to 14.0 mg/g with a mean value of 8.1 mg/g. Alpha-linolenic acid (all cis) concentrations ranged from 30.7 to 60.6 mg/g and their degree of isomerization ranged from 6.0 to 31.5, indicating that the deodorization process varies from one producer to another. From per capita consumption of soybean oil brands in Brazil and their TPFA concentrations, it is possible to conclude that their contribution to the average TPFA intake per person in Brazil is 0.4 g/d. 相似文献
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Shahnaz Khan Farman Ali Nayab Ali Fahim Ullah Khan Sami Ullah Khan 《Natural product research》2016,30(11):1335-1338
Nelumbo nucifera seeds’ essential oil (EO), crude extract and subsequent fractions were evaluated for their DPPH, ABTS and superoxide anion-free radical scavenging and cholinesterase inhibitory activities. The ethyl acetate fraction and EO showed outstanding antioxidant activities with IC50 values of 191, 450 μg/mL (DPPH), 123, 221 μg/mL (ABTS) and 69, 370 μg/mL (superoxide anion). The ethyl acetate fraction and EO also caused significant inhibition of acetylcholinesterase and butyrylcholinesterase with IC50 values of 70 ± 0.6, 64 ± 0.8 and 75 ± 0.3, 58 ± 0.2, in dose-dependent manner. The first ever gas chromatography–mass spectrometry analysis of the EO obtained from N. nucifera seeds resulted in identification of 19 constituents, mainly comprised of oxygenated sesquiterpenes responsible for their promising bioactivity. The crude and fractions revealed the presence of saponins, flavonoids, steroids, alkaloids, terpenoids and cardiac glycosides in phytochemical investigation. 相似文献
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Vera L. P. Soares Regina S. V. Nascimento Sandra R. Albinante 《Journal of Thermal Analysis and Calorimetry》2009,97(2):621-626
Biodiesel from soybean oil transesterified with methanol (TSO) becomes viscous and gelifies at low storage temperatures which makes it difficult to pump. To inhibit this behaviour bulky esters were added to reduce the crystallization temperature of TSO and to modify the rate of conversion of crystallized mass. This rate was found to follow a JMAK kinetic model. The Avrami’s parameter n was constant for TSO, while two n values were found for TSO-additive solutions, meaning that the additives first slowed down the rate of nucleation and, later on as enough nuclei had been formed, crystal growth rate dominated and the previous crystallization rate was recovered. 相似文献
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Papadimitriou V Sotiroudis TG Xenakis A 《Langmuir : the ACS journal of surfaces and colloids》2007,23(4):2071-2077
Microemulsions composed of olive oil, either extravirgin (EVOO) or refined (ROO), as the continuous oil phase, water as the dispersed phase, and a mixture of lecithin-propanol as the emulsifier were prepared and investigated as potential biocompatible media for biotransformations. The area of the microemulsion zone increased considerably by increasing the lecithin to propanol weight ratio in both EVOO- and ROO-based systems. However, the nature of the oil used does not seem to affect the ability of the system to incorporate water. The catalytic activities of two oxidizing enzymes that have been detected in virgin olive oil, namely, tyrosinase and peroxidase, and the activity of a proteolytic enzyme such as trypsin were studied in olive oil microemulsions. In all cases a reduced catalytic activity was observed when ROO was considered as the continuous oil phase. The interfacial properties of lecithin layers were studied by electron paramagnetic resonance spectroscopy employing the nitroxide spin probe 5-doxylstearic acid. By varying the weight ratio of lecithin to propanol and the water content of the microemulsions, the mobility of the probe and the rigidity of the interface were altered. Droplet sizes were measured by dynamic light scattering. At higher water content of the system the size of the droplets was increased. When EVOO was considered as the oil phase, smaller aqueous droplets were formed. Lecithin-based olive oil microemulsions were also characterized with regard to the phenomenon of electrical percolation. At a water content above 3% (w/w) and a lecithin/propanol weight ratio of 2, a sharp increase in conductivity was observed, indicating a structural transition in the bicontinuous form. 相似文献
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M. Nigmonov N. I. Koryakina V. K. Burichenko L. I. Lavrent'eva 《Chemistry of Natural Compounds》1988,24(3):338-342
The results are given of a study of the quantitative content of protein in the seeds of some pea varieties and mutants, the activity of the total inhibitor proteins, and correlations of their activity with the protein content of the seeds and the amino acid compositions of the proteinase inhibitors. Considerable differences have been found in the amounts of a number of amino acids of the protein inhibitors of parental varieties and mutants of the pea, the amounts of serine, glutamic acid, alanine, and valine correlating positively with the inhibitor activity.Institute of Plant Physiology and Biophysics, Tadzhik SSR Academy of Sciences, Dushanbe. V. I. Nikitin Institute of Chemistry, Tadzhik SSR Academy of Sciences, Dushanbe. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 399–404, May–June, 1988. 相似文献
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Yamamoto Y Kurata M Watabe S Murakami R Takahashi SY 《Current protein & peptide science》2002,3(2):231-238
Propeptides of papain-like cysteine proteinases such as papain, cathepsins B, L and S are potent inhibitors of their cognate cysteine proteinases with Ki values in the nanomolar range, and they exhibit highest inhibition selectivity for enzymes from which they originate. Recent studies have identified novel inhibitor proteins that are homologous to the proregions of papain-like cysteine proteinases. Mouse activated T-lymphocytes express cytotoxic T-lymphocyte antigen (CTLA-2), which is homologous to the proregion of mouse cathepsin L. CTLA-2 exhibits inhibitory activities to several cysteine proteinases. We have also identified a similar propeptide-like cysteine proteinase inhibitor, Bombyx cysteine proteinase inhibitor (BCPI), in the silkmoth Bombyx mori. BCPI is a slow and tight binding inhibitor of cathepsin L-like cysteine proteinases with Ki values in picomolar range, and the inhibition is highly selective towards these proteinases just like the propeptides. Recent genome analyses have shown the expression of similar propeptide-like proteins in Drosophila and rat, suggesting the presence of a novel class of cysteine proteinase inhibitors in a variety of organisms. Studies of the gene structures and phylogenetic analysis have shown that genes of the propeptide-like cysteine proteinase inhibitors have emerged from ancestor genes of their parental enzymes. 相似文献
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Fifteen varieties of soybean have been investigated for the amounts of protein, oil, and trypsin inhibitor that they contain. A high thermal stability of the latter has been detected. Information is given on the kinetics of the inhibition of the amidase and proteinase activity of trypsin. It has been shown that the trypsin inhibitor consists of a mixture of six proteins.Institute of Plant Biophysics and Physiology, Academy of Sciences of the Tadzhik SSR, Dushanbe. Institute of Molecular Biology, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 84–88, January–February, 1980. 相似文献
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Summary 1. It has been shown that polypeptide antibiotics — bacitracin and gramicidin S — inhibit carboxylic proteinases — porcine and equine pepsins. Bacitracin inhibits pepsin with KI=2.3 mM, and gramicidin S with KI2 mM.2. The results obtained permit a theoretical foundation for the use of bacitracin and gramicidin S and also of other polypeptide antibiotics as ligands for the biospecific chromatography of proteinases.M. V. Lomonsov State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 385–389, May–June, 1978. 相似文献
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Chemistry of Natural Compounds - 相似文献
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Serine proteinases fulfill and facilitate a broad spectrum of biological processes. They are held in check by different specific inhibitors. This delicate balance can be disturbed by genetic defects or exogenous influences and has been shown as the underlying or promoting cause for a large number of different diseases. For instance, proteinases are under investigation as drug targets for cancer, infections, neurodegenerative diseases, osteoporosis, inflammatory disorders and many more. Dermatological research has contributed greatly to the appreciation of the complex regulatory network between serine proteinases and serine proteinase inhibitors. In addition, proteolytically trimmed proteinase-activated receptors (PARs) trigger keratinocyte proliferation and differentiation as well as leukocyte attraction and activation. New insights have been gained particularly concerning the progression of inflammatory disorders of the skin. This review summarizes the role of serine proteinase inhibitors in physiology and pathophysiology of the skin. 相似文献
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Yumrutas O Sokmen A Akpulat HA Ozturk N Daferera D Sokmen M Tepe B 《Natural product research》2012,26(19):1848-1851
This study was designed to evaluate the in vitro antioxidant activities of n-hexane (Hex), dichloromethane (DCM), methanol (MeOH) and essential oils (EO) extracts obtained from Salvia euphratica var. euphratica and Salvia euphratica var. leiocalycina and to determine their essential oil and phenolic acid compositions. The samples were screened for their antioxidant activity by using DPPH and β-carotene/linoleic acid assays. Methanol extracts of both varieties exhibited strong antioxidant activities. Our results showed that rosmarinic acid was dominant phenolic acid of MeOH extracts (39.4 and 55.8?μg?mg?1, respectively). The chemical compositions of essential oils of two varieties were analysed and their main components were determined as eucalyptol (18.4%) and trans-pinocarvyl acetate (24.9%), respectively. It can be said that these varieties could be used as natural antioxidant. 相似文献
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J. D. Chen G. R. Grant W. A. Boivin M. T. Heinrich A. H. Kerr R. Tkachuk 《Journal of Radioanalytical and Nuclear Chemistry》1995,194(2):359-369
A study has been carried out to determine the levels of radioisotopes in five Canadian grains from pre-(1985) and post-Chernobyl (1986) crop years. In addition, the radioisotope levels were determined in grains from the 1988 crop year consisting of wheats, oats, barley, corn and oil seeds which included flax, sunflower and canola. The grain and oil-seed samples were ashed to reduce their volume, and the gammaemitters137Cs and40K were determined using a high-purity germanium detector and a high-purity germanium well detector. The90Sr activity measurements required further ashing of the samples followed by chemical separations and -counting of the separated daughter90Y. The results for the 1985, 1986 and 1988 crop years are discussed and compared with results from grain crops obtained during years of atmospheric bomb tests in the 1950's. 相似文献
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Protease inhibitors of protein nature have been isolated from dormant cotton seeds. The participation of protease inhibitors in the mechanism of protecting the plant from wilt damage is discussed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 445–448, May–June, 1995. Original article submitted June 27, 1994. 相似文献