The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on ph...The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on phytic acid, crude protein, crude fat, and amino acid profile. Response surface methodology （RSM） with Box-Behnken design was used to optimize SSF. The optimal conditions derived from RSM for L. brevis fermentation were： pH=5. 1; inoculum size=10%; duration=72 h; substrate to water ratio=1.5. The minimum content of trypsin inhibitors was 6.4 mg g^-1 dry matter. The optimal conditions derived from RSM for A. oryzae fermentation were： substrate to water ratio= 0.8 1; inoculum size=4%; duration=120 h. The minimum content of trypsin inhibitors was 1.6 mg g^-1 dry matter. Both L. brevis and A. oryzae decreased trypsin inhibitors dramatically （57.1 and 89.2% respectively）. L. brevis fermentation did not affect phytic acid （0.4%） and crude fat （5.2%） considerably, whereas A. oryzae fermentation degraded phytic acid （34.8%） and crude fat （22.0%） contents to a certain extent. Crude protein content was increased after both fermentation （6.4 and 12.9% for L. brevis and A. oryzae respectively）. Urease activity was reduced greatly （83.3 and 58.3% for L. brevis and A. oryzae respectively）. In conclusion, SSF with A. oryzae and L. brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.展开更多
Short peptides based on the tripeptides, Leu-Arg-Pro and Leu-Lys-Pro, were synthesized by microwave assisted solid-phase synthesis method, in order to make a search for potential inhibitors for angiotensin I-convertin...Short peptides based on the tripeptides, Leu-Arg-Pro and Leu-Lys-Pro, were synthesized by microwave assisted solid-phase synthesis method, in order to make a search for potential inhibitors for angiotensin I-converting enzyme（ACE） with minimum side effects in the treatment of hypertension. One peptide with the sequence Leu-Arg-Pro-Phe-Phe shows the strongest inhibition towards ACE with an IC50 value of 0.26 μmol/L in vitro. The study of structure-activity relationship shows that the introduction of a bulky group into the N-terminal of this series of inhibitors may enlarge steric hindrance, resulting in the poor inhibitory activity towards ACE. The inhibitory activity decreased in turn when L-Pro, D-Pro or Ac6c was at the C-terminal respectively. The binding interaction between each of these inhibitors and testicular ACE（tACE） was performed by molecular docking. The results suggest that Leu-Arg-Pro-Phe-Phe mainly occupied the S1 subsite of tACE, and made contact with tACE via seven H-bonds. It appeared that the site on the peptide that bound with tACE was influenced by the configuration of the amino acid, L or D-form, at the C-terminal of the peptide.展开更多
A general method for the solid phase synthesis of hydro-uracils and thiouracils is described. Resino ester 2 reacts with various primary amines to give secondary amines 3, which are converted to the resino ureas (thio...A general method for the solid phase synthesis of hydro-uracils and thiouracils is described. Resino ester 2 reacts with various primary amines to give secondary amines 3, which are converted to the resino ureas (thioureas) 4 by treatment with isocyanates (isothiocyanates). Preparation of the hydro-uracils and thiouracils 5 is achieved by acidic cyclization-cleavage from the resin. The synthesis is designed to be amenable for structure based library approach to photosystem II D1 protein inhibitors.展开更多
The polymer content in the produced water from Tuoliu Station is about 20 mg/L. Cationic imidazoline-type corrosion inhibitor is used to corrosion control of sewage. The corrosion inhibitor can react with the negative...The polymer content in the produced water from Tuoliu Station is about 20 mg/L. Cationic imidazoline-type corrosion inhibitor is used to corrosion control of sewage. The corrosion inhibitor can react with the negatively charged materials such as anionic polymer and suspended substance by adsorption and merging to form complex aggregates, so that the suspended solids content increases, resulting in suspended solids content of exported sewage has been high. So a new type of non-ionic corrosion inhibitor has been developed and field trials have been performed. The results show that non-ionic corrosion inhibitor can effectively reduce the suspended solids content of wastewater while ensuring the corrosion rate of wastewater.展开更多
基金supported by a research project of the Science and Technology Key Group in Zhejiang Provincethe research projects from the Science and Technology Department of Zhejiang Province,China (2009C12068)
文摘The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on phytic acid, crude protein, crude fat, and amino acid profile. Response surface methodology （RSM） with Box-Behnken design was used to optimize SSF. The optimal conditions derived from RSM for L. brevis fermentation were： pH=5. 1; inoculum size=10%; duration=72 h; substrate to water ratio=1.5. The minimum content of trypsin inhibitors was 6.4 mg g^-1 dry matter. The optimal conditions derived from RSM for A. oryzae fermentation were： substrate to water ratio= 0.8 1; inoculum size=4%; duration=120 h. The minimum content of trypsin inhibitors was 1.6 mg g^-1 dry matter. Both L. brevis and A. oryzae decreased trypsin inhibitors dramatically （57.1 and 89.2% respectively）. L. brevis fermentation did not affect phytic acid （0.4%） and crude fat （5.2%） considerably, whereas A. oryzae fermentation degraded phytic acid （34.8%） and crude fat （22.0%） contents to a certain extent. Crude protein content was increased after both fermentation （6.4 and 12.9% for L. brevis and A. oryzae respectively）. Urease activity was reduced greatly （83.3 and 58.3% for L. brevis and A. oryzae respectively）. In conclusion, SSF with A. oryzae and L. brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.
基金Supported by the National High Technology Research and Development Program of China(No.2006AA10Z331)
文摘Short peptides based on the tripeptides, Leu-Arg-Pro and Leu-Lys-Pro, were synthesized by microwave assisted solid-phase synthesis method, in order to make a search for potential inhibitors for angiotensin I-converting enzyme（ACE） with minimum side effects in the treatment of hypertension. One peptide with the sequence Leu-Arg-Pro-Phe-Phe shows the strongest inhibition towards ACE with an IC50 value of 0.26 μmol/L in vitro. The study of structure-activity relationship shows that the introduction of a bulky group into the N-terminal of this series of inhibitors may enlarge steric hindrance, resulting in the poor inhibitory activity towards ACE. The inhibitory activity decreased in turn when L-Pro, D-Pro or Ac6c was at the C-terminal respectively. The binding interaction between each of these inhibitors and testicular ACE（tACE） was performed by molecular docking. The results suggest that Leu-Arg-Pro-Phe-Phe mainly occupied the S1 subsite of tACE, and made contact with tACE via seven H-bonds. It appeared that the site on the peptide that bound with tACE was influenced by the configuration of the amino acid, L or D-form, at the C-terminal of the peptide.
文摘A general method for the solid phase synthesis of hydro-uracils and thiouracils is described. Resino ester 2 reacts with various primary amines to give secondary amines 3, which are converted to the resino ureas (thioureas) 4 by treatment with isocyanates (isothiocyanates). Preparation of the hydro-uracils and thiouracils 5 is achieved by acidic cyclization-cleavage from the resin. The synthesis is designed to be amenable for structure based library approach to photosystem II D1 protein inhibitors.
文摘The polymer content in the produced water from Tuoliu Station is about 20 mg/L. Cationic imidazoline-type corrosion inhibitor is used to corrosion control of sewage. The corrosion inhibitor can react with the negatively charged materials such as anionic polymer and suspended substance by adsorption and merging to form complex aggregates, so that the suspended solids content increases, resulting in suspended solids content of exported sewage has been high. So a new type of non-ionic corrosion inhibitor has been developed and field trials have been performed. The results show that non-ionic corrosion inhibitor can effectively reduce the suspended solids content of wastewater while ensuring the corrosion rate of wastewater.
