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1.
To detect the flavor quality and flavor compounds in raw longissimus muscle from four typical pig breeds: Sus scrofa?×?Bamei pig named F1 (group A), F1?×?F1 (group B), F1?×?Bamei pig (group C), and F1?×?Large White (group D). The chemical compositions of longissimus muscles from four breeds were examined using headspace solid-phase microextraction/gas chromatography mass spectrometry method. Distinct differences for the same flavor compounds of longissimus muscles between different breeds were analyzed. Totally 64 flavor compounds shared in four groups, and 10 flavor compounds with significant difference among four groups (p?<?0.05), including allyl butyrate, (Z)-2-penten-1-ol, 2,2-dimethyl-3-methyl oxirane, 2-pentylfuran, dodecane, 2,4-decadienal, vinylsilane, 3-methyl-1-butanol, (1-methyldecyl)-benzene, and dipropyl phthalate. Totally, 23–41 flavor compounds did not commonly exist in four groups, such as only as dibutyl isophthalate in group A; 6,10-dimethyl-5-9-undecadien-2 one, bis (2-trimethylsilyl) ethyl ester-malonic acid, heptadecane, 2,4,6-trimethyl pyridine, and diisooctyl adipate in group C alone; and 1,3-dimethylcyclopentanol, 2-octanone, and trimethylsilane in group D alone. While, no specific flavor compounds were identified in group B. All these flavor compounds covered 12 types of hydrocarbons, alcohols, aldehydes, hydroxybenzenes, acids, ketones, esters, sulfides, furans, alkenes, and pyrrole. Besides, we analyzed 14 flavor compounds with different flavors combining with previous studies. The flavor compounds in longissimus muscles might be closely related to the breeds, and the hybrid of S. scrofa?×?Bamei pig had the most flavor compounds in raw longissimus muscle.  相似文献   

2.
The structural features which determine interaction of safrole and related methylenedioxyphenyl compounds with cytochromes P-450 or P-448, and determine the induction of these two classes of the cytochrome, have been studied. All methylenedioxyphenyl compounds studied interact with both cytochromes P-450 and P-448 eliciting type I spectral changes and it has been found that the allyl 4-substituent is important in these interactions. Methylenedioxyphenyl compounds with an oxidised allyl 4-substituent exhibited higher affinity for cytochrome P-448 while those possessing an intact allyl or methylvinyl group generally showed higher affinity for cytochrome P-450. Compounds possessing intact allyl and methylenedioxyphenyl groups (safrole, isosafrole and myristicine) were the most potent inducers of cytochromes P-450 and P-448; compounds containing an intact allyl group only (estragole, allybenzene and eugenol methyl ether) or an oxidized allyl group and an intact methylenedioxyphenyl group (epoxysafrole) were inducers of P-448 only.  相似文献   

3.
18beta-Glycyrrhetinic acid (GA), 3beta-hydroxyl-11-oxo-olean-12-ene-29-oic acid, has been found to inhibit growth and to induce apoptosis in cancer cells. Through structural modification, 16 GA derivatives (12 novel compounds) with modified structures at the C(3) and C(29) positions were synthesized. The antiproliferative effects and apoptosis induction abilities of these compounds were determined in human leukemia HL-60 cells. The replacement of the hydroxyl group of GA with a carbonyl group or an oxime group at C(3) position does not influence the antiproliferative effect. However, the antiproliferative and apoptosis induction abilities of the compounds with a replaced alkoxyimino group at position C(3) and a free C(29) carboxyl group are markedly increased.  相似文献   

4.
Synthetic 6-chromanol derivatives were prepared with several chlorine substitutions, which conferred both electron-withdrawing inductive effects and electron-donating resonance effects. A trichlorinated compound (2), a dichlorinated compound (3), and three monochlorinated compounds (4, 5, and 6) were synthesized; compounds 2, 3, and 6 were novel. The antioxidant activities of the compounds, evaluated in terms of their capacities to scavenge galvinoxyl radical, were associated with the number and positioning of chlorine atoms in the aromatic ring of 6-chromanol. The activity of compound 1 (2,2-dimethyl-6-chromanol) was slightly higher than the activities of compounds 2 (2,2-dimethyl-5,7-dichloro-6-chromanol) or 3 (2,2-dimethyl-5,7,8-trichloro-6-chromanol), in which the chlorine atoms were ortho to the phenolic hydroxyl group of 6-chromanol. The scavenging activity of compound 3 was slightly higher than that of 2, which contained an additional chlorine substituted in the 8 position. The activities of polychlorinated compounds 2 and 3 were higher than the activities of any of the monochlorinated compounds (4-6). Compound 6, in which a chlorine was substituted in the 8 position, exhibited the lowest activity. Substitution of a chlorine atom meta to the hydroxyl group of 6-chromanol (compounds 2 and 6) decreased galvinoxyl radical scavenging activity, owing to the electron-withdrawing inductive effect of chlorine. Positioning the chloro group ortho to the hydroxyl group (compounds 4 and 5) retained antioxidant activity because the intermediate radical was stabilized by the electron-donating resonance effect of chlorine in spite of the electron-withdrawing inductive effect of chlorine. Antioxidant activities of the synthesized compounds were evaluated for correlations with the O-H bond dissociation energies (BDEs) and the ionization potentials. The BDEs correlated with the second-order rate constants (k) in the reaction between galvinoxyl radical and the chlorinated 6-chromanol derivatives in acetonitrile. This indicated that the antioxidant mechanism of the synthesized compounds consisted of a one-step hydrogen atom transfer from the phenolic OH group rather than an electron transfer followed by a proton transfer. The synthesized compounds also exhibited hydroxyl radical scavenging capacities in aqueous solution.  相似文献   

5.
In the continuing search for selective alpha(1)-adrenoceptor (AR) antagonists, new alkoxyarylpiperazinylalkylpyridazinone derivatives were designed and synthesized. The new compounds were tested for their affinity toward alpha(1)-AR, alpha(2)-AR and 5-HT(1A) receptors. The ability of these compounds to inhibit the serotonin transporters (SERT) was also determined. The pharmacological data confirm that increasing the size of the ortho alkoxy substituent on the phenyl ring of the arylpiperazine moiety afforded compounds with enhanced affinity toward the alpha(1)-AR. The isopropoxy group, the largest group evaluated, led the best alpha(1)-AR affinity profile. In contrast, the compounds which have an amide group within of the o-alkoxy-phenylpiperazine fragment showed low affinity toward the receptors studied. Similar results were obtained when the amide group was present in the linker of the junction between the two major constituents of the molecule.  相似文献   

6.
A series of nine synthetic polyaromatic compounds were synthesized by polymerization of aromatic ring monomers with formaldehyde, which yield substantially ordered backbones with different functional anionic groups (hydroxyl and carboxyl) on the phenol ring. These compounds were tested for their heparin-mimicking activity: (1) inhibition of heparanase activity; (2) inhibition of SMC proliferation; and (3) release of bFGF from the ECM. We demonstrate that compounds that have two hydroxyl groups para and ortho to the carboxylic group and a carboxylic group at a distance of two carbons from the phenol ring inhibit heparanase activity and SMC proliferation, as well as induced an almost complete release of bFGF from ECM. Addition of a methyl group next to the carboxylic group led to a preferential inhibition of heparanase activity. Similar results were obtained with a compound that contains one hydroxyl group para to the carboxylic group and an ether group near the carboxylic group on the phenol ring. Preferential inhibition of SMC proliferation was best achieved when the position of the hydroxyl group is para and ortho to the carboxylic group and the carboxylic group is at a distance of one carbon from the phenol ring. On the other hand, for maximal release of bFGF from ECM, the position of the carboxylic group should be three carbons away from the phenol ring. These new heparin-mimicking compounds may have a potential use in inhibition of tumor metastasis, arteriosclerosis, and inflammation.  相似文献   

7.
N-(omega-Hydroxyalkyl)glycolamidobisphosphoric esters (P-O-CH2-CO-NH-(CH2)n -O-P), which are analogues of the aldolase (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate-lyase, EC 4.1.2.13) substrate fructose 1,6-bisphosphate, were synthesized and used for probing its active site. These phosphate compounds competitively inhibited aldolase activity. The Ki value was lowest when the maximum distance between the phosphorus atoms of the bisphosphate was brought close to that of fructose 1,6-bisphosphate. The inhibitor constants, Ki, were compared to those of alkanediol monoglycolate bisphosphoric esters and alkanediol bisphosphate compounds, which were reported previously by Ogata et al. The values of Ki for the bisphosphate compounds containing an amide group, the amide bisphosphate compounds, were smaller than those for the bisphosphate compounds containing an ester group, the ester bisphosphate compounds, and those for alkanediol bisphosphates were the largest for the same distance between phosphorus atoms in these bisphosphates. The difference spectra of aldolase caused by binding of a saturating concentration of N-(omega-hydroxypropyl)glycolamidobisphosphoric ester resembled that of butanediol monoglycolate bisphosphoric ester. However, the effects of the amide bisphosphate compounds on the absorption spectrum of aldolase were smaller than those of the ester bisphosphate compounds for the same distance between phosphorus atoms in these bisphosphate compounds. These results suggest that the synthesized phosphate compounds bind to aldolase at the active site and the -CO-NH- group of the compounds might be held more tightly than the -CO-O- group by hydrogen bonds, presumably with the amino acid residues in the active site, such as Lys-146 or -229 and Asp-33 or Glu-187. On the other hand, the -CO-O- group might be more effective in changing the environment of the Trp-147 residue in the active site of this enzyme.  相似文献   

8.
Results of assessment of biokinetic parameters of change in the burden of significant alpha-emitters in the lungs of mammals in various times after inhalation intake (Qt(lung)) were generalized. 1740 Wistar rats of both sex with the initial age of 2-2.5 months and 143 mature mongrel dogs used in 23 and 3 animal tests, respectively, were involved in this work. The analysis of experimental data resulted in selection of three groups of chemically soluble compounds of alpha-emitters that differ in the rate of radionuclide clearance from the lung as well as in integral doses. Stable complex compounds of quadrivalent and of hexavalent nuclides and non-complex salts of quinquivalent and of hexavalent 237Np were assigned to the group of soluble compounds of 239Pu and 237Np. A three-component exponential model of change in Qt(lung) with the prevalence of fast and of intermediate phases (55%, T(eff) = 0.41 days and 35%, T(eff) = 18.1 days respectively) and the presence of a slow clearance phase (10%, T(eff) = 206 days) was developed for these compounds. Complex compounds of quadrivalent 239Pu and 237Np unstable in the environment of pH and of body temperature, their non-complex salts of mineral acids in ionic or polymer form, and submicron plutonium dioxide (SMD = 0.07 mkm) were assigned to the group of relatively soluble compounds includes. An exponential model with 2-3 components with the prevalence of intermediate and of slow clearance phases (71%, T(eff) = 19.3 days and 22%, T(eff) = 169 days respectively) was developed for compounds of this group. The third group of the compounds is presented based on the soluble 241Am compounds that could be typical for stable trivalent compounds of rare-earth and transuranium radionuclides. Their biokinetics is described by a 3-4-component exponential model with the fast phase prevailing (96.7%, T(eff) < or = 6.8 days), and with intermediate (2.6%, T(eff) = 69 days) and with slow (0.7%, T(eff) = 1040 days) phases being negligible. Physical chemicas and biological processes determining nuclides biokinetics in lungs are discussed.  相似文献   

9.
In the N-acyl-L-prolyl-pyrrolidine type of prolyl oligopeptidase inhibitors the L-prolyl group was replaced by different 5-alkyl-L-prolyl groups, resulting in a series of N-acyl-5-alkyl-L-prolyl-pyrrolidines. Since N-amides of 5-alkyl-L-prolines are conformationally more rigid than those of L-proline, the main objective was to make more rigid prolyl oligopeptidase inhibitors. In the series of compounds where the N-acyl group was a Boc group, the 5(R)-tert-butyl group increased the potency strongly. A similar effect was not observed for the 5(S)-tert-butyl group. In the series of compounds where the N-acyl group was a 4-phenylbutanoyl group, the 5(R)-tert-butyl, 5(R)-methyl and 5(S)-methyl groups did not have an effect on the potency [the 5(S)-tert-butyl group was not tested in this series]. As an additional effect, the 5-tert-butyl groups increased the log P of the compounds 1.5 log units, which might be beneficial when targeting the compounds to the brain.  相似文献   

10.
验证从三白草中提取的两个化合物XGN56和XGN59对自噬关键蛋白ATG4B酶活性的影响及对自噬的调节作用。分子对接的方法验证化合物与游离ATG4B及ATG4B-LC3复合体的氢键结合作用;SDS-PAGE法及荧光共振能量转移法(FRET)测定化合物(10μmol/L)抑制ATG4B的IC50值;LC3融合GFP荧光标签检测化合物(10μmol/L)对LC3荧光聚集的影响,并设置正常组、给药组和药物联用Baf(0.5μmol/L)组;过表达GFP-LC3的WT-MEF及ATG5-/--MEF细胞检测化合物诱导LC3荧光点的情况。结果显示,XGN56和XGN59能分别与游离ATG4B和ATG4B-LC3复合体形成氢键作用,且两者均能剂量依赖地抑制ATG4B的酶切活性,体外IC50分别为7.74μmol/L和8.00μmol/L,同时能够ATG5依赖地促进GFP标记的自噬体的生成(P<0.001)。结果表明,两个化合物可能是通过一定程度地抑制ATG4B的酶活性从而促进细胞自噬水平。  相似文献   

11.
The inhibition mechanism of electrophilic peptide-based protease inhibitors of full-length hepatitis C virus (HCV) NS3 has been investigated by determining the K(i)-values for a series of compounds differing in the electrophilicity and acidity of the C-terminal residue at pH-values above and below the pK(a) of the catalytic histidine (6.85) and at two different ionic strengths. Electrophilic compounds with a pentafluoroethyl ketone group showed stronger inhibition at pH 8 than pH 6, as expected for a mechanism requiring an unprotonated catalytic histidine. However, the difference was only significant at high ionic strength. In contrast, electrophilic compounds with an acidic C-terminal group or a cyclic P1 residue showed a lower inhibitory effect at pH 8 than at pH 6, inconsistent with a mechanism-based inhibition. Moreover, all electrophilic compounds had an unexpectedly strong inhibition at pH 6, when mechanism-based inhibition is unlikely. The results suggest that for some of the electrophilic compounds the reactive group may not be properly positioned in the active site and that binding of these inhibitors is a result of non-covalent interactions. The nature of these interactions is discussed.  相似文献   

12.
To improve the ex vivo potency of MCH inhibitor 1a and to address its hERG liability, a structure-activity study was carried out, focusing on three regions of the lead structure. Introduction of new side chains with basic nitrogen improved in vitro and ex vivo bindings. Many potent compounds with K(i)<10nM were discovered (compounds 6a-j) and several compounds (14-17) had excellent ex vivo binding at 6h and 24h. Attenuating the basicity of nitrogen on the side chain, and in particular, introduction of a polar group such as aminomethyl on the distal phenyl ring significantly lowered the hERG activity. Further replacement of the distal phenyl group with heteroaryl groups in the cyclohexene series provided compounds such as 28l with excellent ex vivo activity with much reduced hERG liability.  相似文献   

13.
The X-ray structure of previously studied dipeptidomimetic inhibitors bound in the active site of neuronal nitric oxide synthase (nNOS) presented a possibility for optimizing the strength of enzyme-inhibitor interactions as well as for enhancing bioavailability. These desirable properties may be attainable by replacement of the terminal amino group of the parent compounds (1-6) with a hydroxyl group (11-13, and 18-20). The hypothesized effect would be twofold: first, a change from a positively charged amino group to a neutral hydroxyl group might afford more drug-like character and blood-brain barrier permeability to the inhibitors; second, as suggested by docking studies, the incorporated hydroxyl group might displace an active site water molecule with which the terminal amino group of the original compounds indirectly hydrogen bonds. In vitro activity assays of the hydroxyl-terminated analogs (11-13 and 18-20) showed greater than an order of magnitude increase in K(i) values (decreased potency) relative to the amino-terminated compounds. These experimental data support the importance to enzyme binding of a potential electrostatic interaction relative to a hydrogen bonding interaction.  相似文献   

14.
Ten analogues of 6'-chloro-3-benzylideneanabaseine (CBA) bearing substituents at the ortho- and the para-positions of the phenyl group were synthesized, together with two related compounds. The affinity of the synthesized compounds for nicotinic acetylcholine receptors (nAChRs) in the nerve cord of the American cockroach (Periplaneta americana L.) was examined by the radioligand binding assay using [(3)H]epibatidine (EPI), a nAChR agonist. All 12 tested compounds inhibited [(3)H]EPI binding, showing K(i) values ranging from 14.6 to 6830nM. The potency variation of para-substituted CBA analogues was explained by the steric (Delta B(1)) and electronic (sigma(p)) parameters of the para-substituents, or by the steric parameter and the charge of the N1 nitrogen atom (qN(1)). Among the CBA analogues, only two compounds containing a dimethylamino group and a methoxy group at the para-position showed high insecticidal activity against the German cockroach (Blattella germanica) when injected after pretreatment with metabolic inhibitors. High-affinity analogues of CBA might be suitable probes for use in classifying and characterizing insect nAChR subtypes.  相似文献   

15.
Hydroxy chalcones, for example, Licochalcone A, has for several years been known to be antibacterial. The low aqueous solubility and the medium antibacterial potency have limited the usefulness of the compounds. We describe the bioisosteric replacement of the essential 4'-hydroxy group in the hydroxy chalcones with bioisosters of varied degrees of acidity resulting in both more potent and more soluble compounds. The more acidic 4'-hydroxy analogues (e.g., 3'-fluoro- or 3',5'-difluoro-) gave almost inactive compounds whereas exchanging the hydroxy group with a carboxy group resulted in a potent compound with a high aqueous solubility. Further optimisation and SAR-analysis resulted in soluble and potent carboxy chalcones [e.g., 3,5-dibromo- and 3,5-di(trifluoromethyl)-].  相似文献   

16.
In order to develop orally active CCR5 antagonists, 1-propyl- or 1-isobutyl-1-benzazepine derivatives containing a sulfoxide moiety have been designed, synthesized, and evaluated for their biological activities. Sulfoxide compounds containing a 2-pyridyl group were first investigated, which led to discovering that the presence of a methylene group between the sulfoxide moiety and 2-pyridyl group was necessary for increased inhibitory activity in a binding assay. After further chemical modification, it was found that replacement of the pyridyl group with an imidazolyl or 1,2,4-triazolyl group enhanced activity in the binding assay and that S-sulfoxide compounds were more active than R-isomers. Particularly, compounds (S)-4r, (S)-4s, and (S)-4w exhibited highly potent CCR5 antagonistic activities (IC50=1.9, 1.7, 1.6 nM, respectively) and inhibitory effects (IC50=1.0, 2.8, 7.7 nM, respectively) in the HIV-1 envelope mediated membrane fusion assay, together with good pharmacokinetic properties in rats. In addition, we established the synthesis of (S)-4r and (S)-4w by asymmetric oxidation with titanium-(S)-(-)-1,1'-bi-2-naphthol complex.  相似文献   

17.
A series of dihydroxyphenylpyrazole compounds were identified as a unique class of reversible Hsp90 inhibitors. The crystal structures for two of the identified compounds complexed with the N-terminal ATP binding domain of human Hsp90alpha were determined. The dihydroxyphenyl ring of the compounds fits deeply into the adenine binding pocket with the C2 hydroxyl group forming a direct hydrogen bond with the side chain of Asp93. The pyrazole ring forms hydrogen bonds to the backbone carbonyl of Gly97, the hydroxyl group of Thr184 and to a water molecule, which is present in all of the published HSP90 structures. One of the identified compounds (G3130) demonstrated cellular activities (in Her-2 degradation and activation of Hsp70 promoter) consistent with the inhibition of cellular Hsp90 functions.  相似文献   

18.
In experiments on the nerve-muscle junction of larvae of the fly Calliphora vicina, regularities of the blocking action of organic cations on ion channels of glutamate postsynaptic receptors have been studied. The measurements were performed by potential fixation on the muscle cell membrane. In total, effects of 26 compounds were studied. The following regularities of structural-functional relations have been revealed: (1) the channels are not blocked by monocation compounds; (2) bication derivatives block efficiently the channels with a certain distance between hydrophobic group and terminal amino group; (3) bication compounds with trimethylammonium terminal group are significantly more efficient than compounds with non-substituted amino group. All these regularities are characteristics of blockade of the AMPA channels, but not of the vertebrate-type NMDA channels. Earlier it was shown that differences in structural-functional relations during blockade of the AMPA and MNDA channels were determined by different location of the hydrophobic and hydrophilic components of the binding area as well as by different diameter of the channels. The fact that channels of the fly larva receptor demonstrate the same regularities of blockade as the vertebrate AMPA channels indicates their structural similarity that is a consequence of their high homology.  相似文献   

19.
As a kind of promising energetic materials, the double furazan-based and furoxan-based compounds have raised concerns of many researchers in recent years. In this paper, the optimized structures, energetic properties, heat of formation (HOF), detonation properties, and bond dissociation energies of these compounds were calculated by density functional theory (DFT) method. The results show that the N-O bond, which is close to the adjacent coordinated oxygen atom in furoxan ring, is more fragile than the other N-O bonds in the ring. The double furazan-based derivatives are more stable than the double furoxan-based derivatives. All the titled compounds are divided into five groups because of the different substitute groups on both ends. The HOFs of the substances offer the order of 4 group (the both ends are 1,2,3,4-tetrazine ) ≈ 5 group (1,2,4,5-tetrazine) > 3 group (tetrazole) ≈ 1 group (1,2,3-triazole) > 2 group (1,2,4-triazole). All the title compounds also can be divided into three types with the different linkages, -N=N-, -N=N(O)-, and -NH-NH-. The results show that the HOFs of the compounds with different linkages obey the order -N=N- type > -N=N(O)- type> -NH-NH- type. For all titled compounds, bis(4-(1,2,4,5-tetrazin-3-yl)-1,2,5-oxadiazol-3-yl) diazene (E5) has the best gas-phase and solid-phase HOFs. The heat of detonation(Q) of bis(3-(1,2,3,4-tetrazin-5-yl)-1,2,5-oxidiazole-2 -oxide)diazene-1,2-diyl (B4) is the best of all titled compounds. The density of bis((3-2H-tetrazol-5-yl)-1,2,5-oxidiazole -2-oxide)oxidodiazene-1,2-diyl (A3) is the best and the second best is bis((4-2H-tetrazol-5-yl)-1,2,5-oxidiazol-3-yl) diazene (E3). The detonation velocities and detonation pressure of A3 and E3 are better than other titled compounds. 1,2-bis((4-2H-tetrazol-5-yl)-1,2,5 -oxidiazol-3-yl) diazene-1-oxide (D3) and 1,2-bis((4-2H-tetrazol-5-yl)-1,2,5-oxidiazol-3-yl) hydrazine (F3) have superior D and P with low sensitivity. The tetrazole ring plays a vital role in improving detonation velocities and pressure. The results can provide some foundational information for designing new high-density energetic materials.  相似文献   

20.
Boron-neutron capture therapy (BNCT) and magnetic resonance imaging (MRI) are quite attractive techniques for treatment and diagnosis of cancer, respectively. In order to develop practical tools for BNCT and MRI, novel compounds containing both the trifluoromethyl group and 10B atom in a single molecule were designed. In the present study, p-boronophenylalanine and p-boronophenylalaninol with the trifluoromethyl group were synthesized, and 19F NMR measurements of these compounds were carried out.  相似文献   

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