排序方式: 共有65条查询结果,搜索用时 0 毫秒
31.
Kokotos G Kotsovolou S Constantinou-Kokotou V Wu G Olivecrona G 《Bioorganic & medicinal chemistry letters》2000,10(24):2803-2806
A number of alkanesulfonyl halides (chlorides and fluorides) and esters were synthesized and their effect on the activity of lipoprotein lipase (LPL) was studied. Sulfonyl fluorides proved to be efficient inhibitors of LPL when the enzyme was incubated with a 10-fold molar excess of the inhibitors in a buffer containing bile salts (deoxycholate). Hexadecane- and dodecanesulfonyl fluorides caused 50% inhibition of LPL activity at concentrations of 10 to 20 μM. 相似文献
32.
Alex L Pereira Thiago N Silva Ana CMM Gomes Ana CG Araújo Loreny G Giugliano 《BMC microbiology》2010,10(1):57
Background
Enteroaggregative Escherichia coli (EAEC) are enteropathogenic strains identified by the aggregative adhesion (AA) pattern that share the capability to form biofilms. Citrobacter freundii is classically considered as an indigenous intestinal species that is sporadically associated with diarrhea. 相似文献33.
Summary Lipidic-amino acids (LAAs) are a class of compounds combining structural features of amino acids with those of fatty acids. They are non-natural-amino acids with saturated or unsaturated long aliphatic side chains. Synthetic approaches to optically active LAAs and lipidic 2-amino alcohols (LAALs) are summarized in this review. A general approach to enantioselective synthesis of saturated LAAs is based on the oxidative cleavage of 3-amino -1,2-diols obtained by the regioselective opening of enantiomerically enriched long chain 2,3-epoxy alcohols. Unsaturated LAAs are prepared in their enantiomeric forms by Wittig reactionvia methyl (S)-2di-tert-butoxycarbonylamino-5-oxo-pentanoate. This key intermediate aldehyde is obtained by selective reduction of dimethyl N,N-di-Boc glutamate with DIBAL. (R) or (S) LAALs may be prepared starting from D-mannitol or L-serine. LAAs are converted into LAALs by chemoselective reduction of their fluorides using sodium borohydride with retention of optical purity. Replacement of the hydroxyl group of LAALs by the azido group, followed by selective reduction leads to unsaturated optically active lipidic 1,2-diamines.Abbreviations Bn
benzyl
- Boc
tert-butoxycarbonyl
- DDQ
2,3-dichloro-5,6-dicyano-1,4-benzoquinone
- DET
diethyl tartrate
- DIBAL
diisobutyl aluminum hydride
- DMAP
4-dimethylaminopyridine
- DMF
N,N-dimethylformamide
- DMSO
dimethyl sulfoxide
- EDC
N-ethyl-N-(3-dimethylaminopropyl)carbodiimide
- Et3N
triethylamine
- HMPA
hexamethylphosphoramide
- HOBt
1-hydroxybenzotriazole
- KN(TMS)2
potassium bis(trimethylsilyl)-amide
- LAA
lipidic-amino acid
- LAAAl
lipidic 2-amino alcohol
- LDA
lipidic 1,2-diamine
- LP
lipidic peptide
- MPM-Cl
p-methoxybenzyl chloride
- MsCl
methanesulphonyl chloride
- MTPA
-methoxy--(trifluoromethyl)phenylaccitc
- PLA2
phospholipase A2
- TBIIP
tert-butyl hydroperoxide
- THF
tetrahydrofuran
- TMSCl
trimethylsilyl chloride
- Tr
trityl
- Z
benzyloxycarbonyl 相似文献
34.
35.
Miller DJ Hemmrich G Ball EE Hayward DC Khalturin K Funayama N Agata K Bosch TC 《Genome biology》2007,8(4):R59
Background
Characterization of the innate immune repertoire of extant cnidarians is of both fundamental and applied interest - it not only provides insights into the basic immunological 'tool kit' of the common ancestor of all animals, but is also likely to be important in understanding the global decline of coral reefs that is presently occurring. Recently, whole genome sequences became available for two cnidarians, Hydra magnipapillata and Nematostella vectensis, and large expressed sequence tag (EST) datasets are available for these and for the coral Acropora millepora. 相似文献36.
John E. Blundell Clare L. Lawton Jason CG Halford 《Obesity (Silver Spring, Md.)》1995,3(Z4):471S-476S
There is an intimate relationship between nutritional intake (eating) and serotonin activity. Experimental manipulations (mainly neuropharmacological) of serotonin influence the pattern of eating behavior, subjective feelings of appetite motivation, and the response to nutritional challenges. Similarly, nutritional manipulations (food restriction, dieting, or altered nutrient supply) change the sensitivity of the serotonin network. Traditionally, serotonin has been linked to the macronutrient carbohydrate via the intermediary step of plasma amino acid ratios. However, it has also been demonstrated that 5-HT drugs will reduce energy intake and reverse body weight gain in rats exposed to weight increasing high fat diets. 5-HT drugs can also reduce food intake and block weight gain of rats on a high fat cafeteria diet. Some diet selection studies in rats indicate that the most prominent reduction of macronutrient intake is for fat. These data indicate that 5-HT activity can bring about a reduction in fat consumption. In turn, different types of dietary fat can alter brain 5-HT activity. In human studies the methodology of food choice experiments has often precluded the detection of an effect of 5-HT manipulation on fat intake. However, there is evidence that in obese and lean subjects some 5-HT drugs can readily reduce the intake of high fat foods. Data also suggest that 5-HT activation can lead to a selective avoidance of fat in the diet. These effects of 5-HT on the intake of dietary fat may involve a pre-absorptive mechanism and there is evidence that 5-HT is linked to cholecystokinin and enterostatin. These proposals have theoretical and practical implications and suggest possible strategies to intensify or advance fat-induced satiety signals. 相似文献
37.
Central nerve terminals contain a small number of synaptic vesicles (SVs) that must sustain the fidelity of neurotransmission across a wide range of stimulation intensities. For this to be achieved, nerve terminals integrate a number of complementary endocytosis modes whose activation spans the breadth of these neuronal stimulation patterns. Two such modes are ultrafast endocytosis and activity‐dependent bulk endocytosis, which are triggered by stimuli at either end of the physiological range. Both endocytosis modes generate endosomes directly from the nerve terminal plasma membrane, before the subsequent production of SVs from these structures. This review will discuss the current knowledge relating to the molecular mechanisms involved in the generation of SVs from nerve terminal endosomes, how this relates to other mechanisms of SV production and the functional role of such SVs. 相似文献
38.
39.
C. Fotakis E. Siapi K. Viras C.G. Kokotos S. Golic Grdadolnik M. Rappolt T. Mavromoustakos 《生物化学与生物物理学报:生物膜》2010,1798(3):422-432
This work presents a thorough investigation of the interaction of the novel synthetic pyrrolidinone analog MMK3 with the model membrane system of dipalmitoylphosphatidylcholine (DPPC) and the receptor active site. MMK3 has been designed to exert antihypertensive activity by functioning as an antagonist of the angiotensin II receptor of subtype 1 (AT1). Its low energy conformers were characterized by 2D rotating-frame Overhauser effect spectroscopy (ROESY) in combination with molecular dynamics (MD) simulations. Docking study of MMK3 shows that it fits to the AT1 receptor as SARTANs, however, its biological activity appears to be lower. Thus, differential scanning calorimetry (DSC), Raman spectroscopy and small angle X-ray scattering (SAXS) experiments on the interaction of MMK3 with DPPC bilayers were carried out and results demonstrate that the drug is well incorporated into the membrane leaflets and furthermore causes partial bilayer interdigitation, although less effective than SARTANs. Thus, it appears that the nature of the bilayer matrix and the stereoelectronic active site requirements of the receptor are responsible for the low bioactivity of MMK3. 相似文献
40.
Small-subunit ribosomal RNA sequence from Naegleria gruberi supports the polyphyletic origin of amoebas 总被引:2,自引:0,他引:2
We have sequenced the small-subunit ribosomal RNA gene of the amoebo-
flagellate protozoan Naegleria gruberi. Comparison of this sequence with
the rRNA sequences of other eukaryotes resulted in a phylogenetic tree that
supports the suggested polyphyletic origin of amoebas and suggests a
flagellate ancestry for Naegleria.
相似文献