Molecular characteristics and structure–activity relationships of food-derived bioactive peptides

Peptides are functional active fragments of proteins which can provide nutrients needed for human growth and development,and they also have unique physiological activity characteristics relative to proteins.Bioactive peptides contain a great deal of development potential.More specifically,food-derived bioactive peptides have the advantages of a wide variety of sources,unique structures,high efficiency and safety,so they have broad development prospects.This review provides an overview of the current advances regarding the preparation,functional characteristics,and structure–activity relationships of food-derived bioactive peptides.Moreover,the prospects for the future development and application of food-derived bioactive peptides are discussed.This review may provide a better understanding of foodderived bioactive peptides,and some constructive inspirations for further research and applications in the food industry.

The Crustal Structure and Seismic Activity in North China

A layered crustal block model of North China has been constructed based on large amount of data from seismic sounding carried out in recent two decades. Some deep fault zones, such as the Zhangjiakou.Penglai and Tancheng-Lujiang fault zones, divide the upper crust of North China into three upper crustal terranes and nine bolcks. There are distinct differences in velocity and depth distributions, which reflects Cenozoic block faulting in North China in the process of formation of the deep structure. The upper crust shows the features of transition in isostatic adjustment. The existence of a low-velocity layer in the middle crust is characteristic of the crustal structure in North China. There seems to be an increase of rheology of the rocks in the lower crust and a persistence of stable regional stress field. The patterns of the Moho on two sides of the Yanshan-Taihang Mountains are different. The relief of the Moho around Beijing, Shijiazhuang and Guangrao where the deep faults join together shows a quadrantal distribution in some degree. The dynamic sources for seismic activity are the NE-SW horizontal compression and the diapirism of the upper mantle. The middle and upper crust, especially the layered block structure has the most significant effects on seismicity, and the occurrence of earthquakes is more closely related to them than to the Moho.

Synthesis,Crystal Structure and Antifungal Activity of 8-Chloro-3-((4-chlorobenzyl)-thio)[1,2,4]triazolo[4,3-a]pyridine

The title compound 8-chloro-3-（（4-chlorobenzyl）thio）-[1,2,4]triazolo[4,3-a]pyridine was prepared from 1-chloro-4-（chloromethyl）benzene and 8-chloro-[1,2,4]triazolo[4,3-a]pyridine-3（2H）-thione in the presence of Na OH, and its structure was determined by X-ray diffraction analysis. The crystal is of triclinic system, space group P1 with a = 6.8264（6）, b = 7.5890（4）, c = 13.0960（7） A, α = 93.447（4）, β = 98.772（6）, γ = 92.615（6）o, V = 668.26（8） A3, Z = 2, the final R = 0.035 and wR = 0.09 for 2259 observed reflections with I 〉 2σ（I）. The preliminary biological test showed that the title compound has activities against Stemphylium lycopersici（Enjoji） Yamamoto, Fusarium oxysporum. sp. cucumebrium, and Botrytis cinerea with inhibitory to be 51.19%, 62.02% and 15.56%, respectively.

Synthesis,Crystal Structure,DFT Studies and Biological Activity of a Novel Schiff Base Containing Triazolo[4,3-a]pyridine Moiety

The novel Schiff base（E）-8-chloro-NA-（4-（dimethylamino）benzylidene）-[1,2,4]triazolo[4,3-a]pyridine-3-carbohydrazide was synthesized and characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction.The compound crystallizes in the monoclinic space group P2_1/c with a = 7.091（2）,b = 10.750（3）,c = 21.380（6） A,β = 96.299（6）°,V = 1619.7（8） A^3,Z = 4 and R = 0.0351.Theoretical calculation of the title compound was carried out with the B3LYP/6-31 G basis set.The frontier orbital energy and atomic net charges were discussed.It is found that the experimental data show good agreement with the calculated values.And the compound exhibits good antifungal activity against Stemphylium lycopersici（Enjoji） Yamamoto.

Structure and Anti-HIV Activity of Betulinic Acid Analogues

Firstly discovered in 1980s, human immunodeficiency virus （HIV） continues to affect more and more people. However, there is no effective drug available for the therapy of HIV infection. Betulinic acid existing in various medicinal herbs and fruits exhibits multiple biological effects, especially its outstanding anti-HIV activity, which has drawn the attentions of many pharmacists. Among the derivatives of betulinic acid, some compounds exhibited inhibitory activities at the nanomolar concentration, and have entered phase II clinical trials. This paper summarizes the current investigations on the anti-HIV activity of betulinic acid analogues, and provides valuable data for subsequent researches.

Synthesis,Crystal Structure,DFT Studies and Antifungal Activity of 5-(4-Cyclopropyl-5-((3-fluorobenzyl)sulfonyl)-4H-1,2,4-triazol-3-yl)-4-methyl-1,2,3-thiadiazole

5-（4-Cyclopropyl-5-（（3-fluorobenzyl）sulfonyl）-4H-1,2,4-triazol-3-yl）-4-methyl-1,2,3-thiadiazole was synthesized and recrystallized from Et OH. The compound was characterized by ^1H NMR,MS,elemental analysis and X-ray diffraction. The structure-active relationship and the antifungal activity based on density functional theory calculation（DFT） and antifungal activities were investigated. The compound crystallizes in the monoclinic space group P121/n1 with a = 8.929（3）,b=12.715（4）,c=15.161（5） A°,β = 106.142（3）o,V = 1653.3（9） A°3,Z = 4 and R = 0.0393 for 3930 observed reflections with I 〉 2σ（I）. Theoretical calculation of the title compound was carried out with B3LYP/6-31G（d,p）. The full geometry optimization was carried out using the 6-31G（d,p） basis set.The frontier orbital energy and atomic net charges were discussed. The observed results of the compound have been compared with theoretical results and the experimental data show good agreement with the calculated values. The compound exhibits good antifungal activity.

Synthesis,Crystal Structure and Anti-fungal Activity of 2-(4-Chlorophenyl)-(1,3-dimethyl-2,3-dihydro-1H)-perimidine

The title compound 2-（4-chlorophenyl）-1,3-dimethyl-2,3-dihydro-1H-perimidine（C（19）H（17）ClN2） was synthesized and characterized by elemental analysis, ^1H NMR, HRMS and single-crystal X-ray diffraction. The crystal of the title compound belongs to orthorhombic system,space group Pnma with a = 11.385（2）, b = 12.170（2）, c = 11.210（2）A, V = 1553.2（5）A^3, Z = 4, Dc =1.321 g/cm^3, m（Mo-Ka） = 0.244 mm^-1, F（000） = 648, S = 1.309, R = 0.0400 and w R（I 〉 2s（I）） =0.1065. X-ray diffraction results showed that the molecular structure is highly symmetric and the new-formed N-heterocyclic ring is non-planar. In addition, the biological experiment showed that the title compound showed inhibitory activities against fungi with varied potencies.

Synthesis,Crystal Structure and Antifungal Activity of 2-((2-Fluorobenzyl)thio)-5-(pyridin-4-yl)-1,3,4-oxadiazole

The title compound 2-（（2-fluorobenzyl）thio）-5-（pyridin-4-yl）-1,3,4-oxadiazole（C_（14）H_（10）FN_3OS） was synthesized,and its structure was confirmed by ~1H NMR,MS,elemental analyses and X-ray diffraction. It crystallizes in the monoclinic system,space group P21/n with a = 11.541（16）,b = 8.226（12）,c = 13.683（19） ？,β = 94.872（17）o,V = 1294（3） ？~3,Z = 4 and R = 0.0648 for 2198 observed reflections with I 〉 2σ（I）. The preliminary biological test shows that the title compound has good activity against Pythium ultimum with inhibitory to be 100%.

Synthesis, Structure and Antimicrobial Activity of 9,9-Dimethyl-9,10-dihydrospiro[benzo[a]-xanthene-12,3'-indoline]-2',11(8H)-dione

One novel spiro-compound（C_（26）H_（21）NO_3） has been synthesized and characterized by means of NMR spectroscopy,elemental analyses and X-ray diffraction. The single crystal belongs to the monoclinic system,space group P21/c with a = 8.8039（7）,b = 24.123（2）,c = 10.0751（9） ？,β = 108.403（3）°,M3r = 395.44,V = 2030.3（3） ？~3,Z = 4,D_c = 1.294 g/cm,F（000） = 832.0,μ = 0.085 mm^（-1）,R = 0.0801 and wR = 0.2228. The title compound shows good activities against Micrococcus tetragenus,Bacillus cereus,Bacillus subtilis,Staphylococcus aureus,S.albus and Escherichia coli.

Synthesis,Crystal Structure and Antifungal Activity of N-((2,6-Difluorophenyl)carbamoyl)-1,3-dimethyl-1H-pyrazole-4-carboxamide

The title compound N-（（2,6-difluorophenyl）carbamoyl）-1,3-dimethyl-1 H-pyrazole-4-carboxamide（C13H12F2N4O2） was synthesized, and its structure was confirmed by ^1H NMR,HRMS and X-ray diffraction. It crystallizes in the monoclinic system, space group P21/c with a = 9.50（2）, b = 10.11（2）, c = 14.07（3） A^°, β = 102.15（3）°, Dc = 1.480 g/cm^3, Z = 4, V = 1320（5） A^°3, the final R = 0.0789 and wR = 0.1860 for 1054 observed reflections with I 〉 2σ（I）. The preliminary biological test shows that the title compound has weak antifungal activities.

Synthesis, Crystal Structure and Neuroprotective Activity of(E)-1-(4-(4-Chlorobenzyl)piperazin-1-yl)-3-(benzo[d][1,3]dioxol-5-yl)prop-2-en-1-one

The crystal structure of the new cinnamide derivative（E）-1-（4-（4-chlorobenzyl）piperazin-1-yl）-3-（benzo[d][1,3]dioxol-5-yl）prop-2-en-1-one（C（21）H（21）ClN2O3, Mr = 384.85） was determined by single-crystal X-ray diffraction method. Compound 5 crystallizes in the monoclinic system, space group P21/c with a = 11.762（2）, b = 15.279（3）, c = 11.865（2） , β = 116.57（3）°, V = 1907.1（7） 3, Z = 4, Dc = 1.340 g/cm3, F（000） = 808, μ = 0.224 mm-1, Mo Kα radiation（λ = 0.71073 ）, the final R = 0.0565 and w R = 0.1479 for 2318 observed reflections with I 〉 2σ（I）. Intramolecular C（9）–H（9A）···O（1） interactions as well as intermolecular C（16）–H（16A）···O（1） hydrogen bonds help to stabilize the crystal structure. The bioassay results indicated that the title compound displayed promising neuroprotection in vitro and in vivo, and suppressed apoptosis of glutamate-induced PC12 cells.

A New Co(Ⅱ)Coordination Compound Constructed by Tripyridyltriazole and Pyromellitic Acid:Synthesis,Crystal Structure and Antifungal Activity

A new coordination compound, [Co（L223）2（H2O）2]·H2pm（1, L223 = 3,4-bis（2-pyridyl）-5-（3-pyridyl）-1,2,4-triazole and H4 pm = pyromellitic acid）, has been synthesized. The structure of complex 1 has been characterized by X-ray single-crystal diffraction, elemental analysis, IR spectrum analysis and thermogravimetric analysis. Single-crystal X-ray diffraction analysis reveals that complex 1 belongs to the triclinic system, space group P1 with a = 10.2470（8）, b = 10.2879（9）, c = 10.2951（11） ？, α = 109.398（2）, β = 97.6590（10）, γ = 95.3260（10）°, V = 1003.60（16） ？3, Z = 1, Dc = 1.565 g/cm^3, μ = 0.508 mm%^-1, Mr = 945.73, F（000） = 485, the final R = 0.0562 and w R = 0.0783 with I 〉 2σ（I）. Two L223 as chelating ligands link one Co（II） ion to form a 0D motif. Furthermore, the 0D motifs are linked into a 2D coordination pattern with hydrogen bonds. In addition, the antifungal effects of the ligand and the complex were evaluated by the disc diffusion method against Colletotrichum gloeosporioides Penz. 1 represents antifungal activity with high levels of inhibitory potency which is larger than the corresponding ligand.

Synthesis,Crystal Structure,Thermal Stability and Anti-tumor Activity In Vitro of Bis(tricyclohexyltin) Pimelicarboxylate

Bis（tricyclohexyltin） pimelicarboxylate, [（CH2）5（CO2SnCy3）2] （1）, has been synthesized by the reaction of tricyclohexyltin hydroxide with pimelic acid and characterized by means of 1R, 1H and 13C NMR, elemental analysis and X-ray diffraction. Complex 1 crystallizes in triclinic space group Pi with a = 11.569（3）, b = 12.0419（2）, c = 17.3988（4） A, α = 81.4310（10）, β = 79.8270（10）, ）, = 69.7060（10）°, V = 2227.60（9） A3, Z = 2, C43H7604Sn2, Mr = 894.42, Dc = 1.333 g.cm-3, μ = 1.157 mm-1, F（000） = 932, GOOF = 1.339, the final R = 0.0452 and wR = 0.1333 for 6709 observed reflections （1〉 2σ（I）. Complex 1 shows discrete dimeric structures and the tin atoms have a distorted tetrahedral geometry. The 1D chain structure of complex 1 is formed by intermolecular Sn…O interactions. Complex 1 displays good thermal stability under 553 K and has selective antibacterial property. Complex 1 is strong in vitro anti-tumor activity against five human tumor cell lines, Colo205, HepG2, MCF-7, Hela and NCI-H460, and is significantly higher than that in the clinical use of carboplatin.

Synthesis,Crystal Structure and Antitumor Activity of a New Indolequinone Derivative of Ursolic Acid

The title compound（C（37）H（48）BrNO5, 6） was synthesized from ursolic acid and its crystal structure was determined by single-crystal X-ray diffraction analysis. The compound is of orthorhombic system, space group P212121 with a = 16.846（3）, b = 18.844（4）, c = 11.262（2）A, Z =4, V = 3575.1（13） A^3, Mr = 666.67, Dc = 1.239 Mg/m^3, S = 1.002, μ = 1.190 mm^-1, F（000） = 1408,the final R = 0.0831 and wR = 0.1459 for 2286 observed reflections（I 〉 2σ（I））. The crystal structure is stabilized by two intermolecular hydrogen bonds（N–H（0A）···O（2） and O（1）–H（1A）···O（3））. In the preliminary antitumor assay, the title compound 6 exhibits potent cytotoxic activity against Hep G2 and SMMC-7721 cells with IC50 values of 1.64 ± 0.21 and 1.22 ± 0.13 μM, respectively.

On quantitative structure-activity relationships between hydrazine derivatives and β irradiation

In this study, solutions of hydrazine and its derivatives were irradiated using a pulsed electron beam to determine the half-reaction time of radiolysis. 3 D structures of the hydrazine derivatives were optimized, and their energies were calculated using density functional theory with the B3 LYP method and 6-311 +(3 d, 3 p) basis set.For the first time, the 3 D quantitative structure-activity relationship(QSAR) equation describing the relationship between the hydrazine derivative structures and rate of radiolysis has been established using SPSS software.Pearson correlation analysis revealed a close correlation between the total energies of the molecules and half-reaction times. In the QSAR equation, Y =-7583.464 +54.687 X_1+94333.586 X_2,Y,X_1,and X_2 are the half-reaction time, total energy of the molecule, and orbital transition energy, respectively. The significance levels of the regression coefficients were 0.006 and 0.031, i.e., both less than 0.05. Thus, this model fully explains the relationship between hydrazine derivatives and β radiolysis stability.The results show that the total energy of the molecule and orbital transition energy are the main factors that influence the β radiolysis stability of these hydrazine derivatives.

Helioal Structure and Optical Activity of Two New Derivatives of R(+)-1,1'-Binaphthyl-2,2'-diol

Correlation between the belieal structure and optical activity of two derivatives of R(+)- 1, 1'-binaphthyl-2,2'-diol was derived from a study of their optical rotations, CD curves and Xray crystal structures.

Quantitative structure－activity study on the reductive dehalogenation potency of the halogenated aromatics

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Synthesis, Crystal Structure and Antitumor Activity of 4-(tert-butyl)-5-(1H-1,2,4-triazol-1-yl)-N-(2-hydroxy-3,5-diiodinebenzyl)-thiazol-2-amine

The title compound, 4-（tert-butyl）-5-（1 H- 1,2,4-triazol- 1 -yl）-N-（2-hydroxy-3,5-diio- dinebenzyl）thiazol-2-amine, was synthesized via the reduction of 4-（tert-butyl）-5-（1H-l,2,4- triazol-l-yl）-N-benzylidene-thiazol-2-amine with NaBH4, and its crystal structure was determined by single-crystal X-ray diffraction. The compound crystallizes in monoclinic system, space group P21/c with a = 7.91944（19）, b = 10.5250（3）, c = 24.4985（6） A, Z = 4, V = 2041.66（9） A3, Mr = 599.22, Dc = 1,949 Mg/m3, S = 1.120, p = 3.203 mm-1, F（000） = 1152, the final R = 0.0283 and wR = 0.0592 for 3490 observed reflections （I 〉 2σ（I））. X-ray analysis displays that the crystal water takes part in three intermolecular hydrogen bonds of O（2）-H（2A）…O（1）, O（2）-H（2B）…N（I） and N（5）-H（5）…O（2）, and an octatomic ring R^（8） is formed via intramolecular hydrogen bond of O（I）-H（IA）…N（4）. Furthermore, the I…I contacts are involved in stabilizing the overall three-dimensional network structure. The preliminary biological test shows the title compound has good antitumor activity with the IC50 value of 26 μM against the Hela cell line.

Synthesis,Crystal Structure and Antitumor Activity of 6-Chloro-1-((6-chloropyridin-3-yl)methyl)-3-phenyl-1H-benzofuro[3,2-c]pyrazole

The title compound 6-chloro-l-（（6-chloropyridin-3-yl）methyl）-3-phenyl-lH-benzofuro[3,2-c]pyrazole（5,C21H13Cl2N3O,Mr = 394.26） was synthesized and characterized by elemental analysis,^1H NMR,^13C NMR and X-ray single-crystal diffraction.The structure reveals that the crystal belongs to the triclinic system,space group P1 with a = 7.8829（8）,b = 10.3281（10）,c = 11.7615（12）A°,α = 83.5552（2）,β = 79.921（2）,γ = 70.189（2）°,V= 885.54（15） A°3,Z = 2,Dc =1.479 g/cm^3,μ = 0.383 mm^-1,F（000） = 404,R = 0.0538 and wR = 0.1335 for 2453 observed reflections with I 〉 2σ（I）.The result reveals that the crystal structure of the title compound 5 is stabilized by three C-Cl…π interactions and π…π stacking interaction.In addition,the preliminary investigation showed that 5 exhibits remarkably good antitumor activity against the MCF-7 and A549 cell lines.

Structure - Antimicrobial Activity Relationship Investigation of Some Butadiene and Chalcone Derivatives

The biological activity against Staphylococcus aureus, and Eschericia coil were investigated implementing three series, the first series was l-phenyl-2-（4＇-X-phenyl）-4-（2,4-dichlorophenyl）-1,3-butadiene, where X = H, CH3, OCH3, NH2, C1, F, NO2 and COOEt; the second was 3,4-dichlorochalcone series namely 3-（3,4-dichlorophenyl）-l-（4＇-X-phenyl）-2-propen-l-one, where X = H, CH3, OCH3, NH2, CI, F, NO2 and CN; and the third one was 2,4-dichlorochalcone series namely 3-（2,4-dichlorophenyl）-l- （4＇-X-phenyl）-2-propen-l-one, where X = H, CH3, OCH3, NH2, C1, F, NO2 and COOEt. MIC, MBC and the percentage of inhibition （activity） at 20 ~tg/mL, 15 μg/mL and 10μg/mL against Eschericia coli, and at 7.5 lag/mL, 5 μg/mL and 2.5 μg/mL against Staphylococcus aureus, were determined for each compound in the three series. Highest MIC activity against E. coli and S. aureus were given by 2,4-dichlorochalcone series. Butadiene series was similar in behavior to 2,4-dichlorochalcone series in MIC activity against S. aureus. Results of MBC revealed that compounds in the three series exerted high activity against both types of bacteria. Compounds substituted with nitro or nitril exhibited higher activity than other compounds in the three series. Percentage of inhibition of halogenated compounds （4＇-C1 and 4＇-F） was almost equal in every series. Compounds with substituents （4＇-H and 4＇-CH3） showed fluctuation in activity according to the nature of each series.