Route I: The amino group of S-homoserine was protected with methyl chloroformate followed by acidification to pH 1-2. The solvent was evaporated at 60°C, and the residue was extracted with ethylacetate and then crystallized from ethylacetate to produce S-α-(methyloxycarbonyl)amino-γ-butyrolactone with an overall yield of 49.8%.
Methods: The surface of titanium were implanted by calcium-ion in amounts of 1×10 18 ,5×10 17 ,1×10 17 ions/cm 2, after implanted by amino group in amount of 5×10 16 ions/cm 2,The modified surface has been characterized using X ray photoelectron spectroscopy (XPS) and scanning electron microscope(SEM).
The amino group of 4-aminophenol was protected by benzaldehyde first and then was polymerized in dioxane / buffer using HRP as catalyst. We conduct several experiments and conclude the best condition is: 1,4-dioxane/buffer=0.7, pH=7 and the concentration of substrate is 0.15 mol/L.
The aminopolysi- loxane with regular distribution of amino groups in the molecule was synthesized under the conditions that the molar ratio of WS-62M to SG-Si900 was 1.33:1,the mass ratio of triethylamine was 1.53%,reaction temperature was 120 ℃,reaction time was 10 h,and vacuum time under a pressure of 0.01 MPa was 0.5～1 h.
Compared with Cu2+ ( lipid peroxidative ) modification, LDL modified directly by MDA ( 10mmol/L ) could only decrease the content of free amino groups and enhance electrophoretic mobility, but without the other changes as occured in case of Cu2+ modified LDL.
At the condition of 50℃ and no pH regulation,with the addition of Alcalase and Flavourzyme together, the optimal parameters were Alcalase 0.006-0.021AU/gSBM, Flavourzyme 2LAPU/gSBM,and 6-10.5hr with the results of amido nitroges 8.807%-13.33% and TCA-NSI 31.66%-56.53%.
At the condition of 50℃ and no pH regulation, with the addition of Neutral proteinase and acid proteinase together, the optimal parameters were Neutral proteinase 200-1100U/gSBM, acid proteinase 100U/gSBM, 6-10.5hr with the results of amido nitrogens 6.76%-9.54% and TCA-NSI 32.22%-54.58%.
The location of the amino group on ring B also affected cytotoxicity.
Besides the hydrophobic interaction provided by nonpolar dodecyl, DPZ also has dipolar interaction, ion-exchange or electrostatic repellent interaction provided by the free phosphonic group and amino group at different conditions.
In the synthesis of Compound A, the reactive processes used by us included the protection of amino group of lysine, acetylation, and intramolecular cyclizative condensation reaction.
Benzoxycarbonyl chloride was selected as amino group protection agent, and the yield was elevated by replacing sodium bicarbonate with triethyl amide as the acid's neutralizer.
The presence of a primary amino group in the chitosan structure allows for the synthesis of various derivatives.
The two amino groups of amine templates reacted favorably with Zn2+ to form uniform and relatively smooth ZnS nanospheres with holes, while hydroxyethyl played a disadvantageous role.
The Fourier transform infrared (FTIR) spectra confirmed the formation of an amide linkage between amino groups of carboxymethyl chitosan (CMCS) and carboxyl groups of oleic acid.
Polymeric systems with antithrombin activity and an LCST were prepared via a reaction of amino groups of hirudin with phthalimide groups of the copolymers.
The differences in sorption characteristics of starch and chitosan were related to the presence of amino groups in the latter polysaccharide, which contributed to an increased binding of aldehydes via polar interactions.
These derivatives are well soluble at pH values greater than the acidity constant of amino groups of chitosan (6.5).