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1.
Jeannine M. Coburn Nicholas Bernstein Rahul Bhattacharya Udayanath Aich Kevin J. Yarema Jennifer H. Elisseeff 《PloS one》2013,8(3)
Articular cartilage has a limited ability to self-repair because of its avascular nature and the low mitotic activity of the residing chondrocytes. There remains a significant need to develop therapeutic strategies to increase the regenerative capacity of cells that could repair cartilage. Multiple cell types, including chondrocytes and mesenchymal stem cells, have roles in articular cartilage regeneration. In this study, we evaluated a platform technology of multiple functionalized hexosamines, namely 3,4,6-O-tributanoylated-N-acetylgalactosamine (3,4,6-O-Bu3GalNAc), 3,4,6-O-tributanoylated-N-acetylmannosamine (3,4,6-O-Bu3ManNAc) and 3,4,6-O-Bu3GlcNAc, with the potential ability to reduce NFκB activity. Exposure of IL-1β-stimulated chondrocytes to the hexosamine analogs resulted in increased expression of ECM molecules and a corresponding improvement in cartilage-specific ECM accumulation. The greatest ECM accumulation was observed with 3,4,6-O-Bu3GalNAc. In contrast, mesenchymal stem cells (MSCs) exposed to 3,4,6-O-Bu3GalNAc exhibited a dose dependent decrease in chondrogenic differentation as indicated by decreased ECM accumulation. These studies established the disease modification potential of a hexosamine analog platform on IL-1β-stimulated chondrocytes. We determined that the modified hexosamine with the greatest potential for disease modification is 3,4,6-O-Bu3GalNAc. This effect was distinctly different with 3,4,6-O-Bu3GalNAc exposure to chondrogenic-induced MSCs, where a decrease in ECM accumulation and differentiation was observed. Furthermore, these studies suggest that NFκB pathway plays a complex role cartilage repair. 相似文献
2.
Langqiu Chen Shen-De Shi Yong-Qing Liu Qing-Jiao Gao Xing Yi Kai-Ke Liu Hao Liu 《Carbohydrate research》2011,346(10):1250
A novel 1,2-cis stereoselective synthesis of protected α-d-Gal-(1→2)-d-Glc fragments was developed. Methyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-α-d-galactopyranosyl-(1→2)-3-O-benzoyl-4,6-O-benzylidene-α-d-glucopyranoside (13), methyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-α-d-galactopyranosyl-(1→2)-3,4,6-tri-O-benzoyl-α-d-glucopyranoside (15), methyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-α-d-galactopyranosyl-(1→2)-3-O-benzoyl-4,6-O-benzylidene-β-d-glucopyranoside (17), and methyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-α-d-galactopyranosyl-(1→2)-3,4,6-tri-O-benzoyl-β-d-glucopyranoside (19) were favorably obtained by coupling a new donor, isopropyl 2-O-acetyl-3-O-allyl-4,6-O-benzylidene-1-thio-β-d-galactopyranoside (2), with acceptors, methyl 3-O-benzoyl-4,6-O-benzylidene-α-d-glucopyranoside (4), methyl 3,4,6-tri-O-benzoyl-α-d-glucopyranoside (5), methyl 3-O-benzoyl-4,6-O-benzylidene-β-d-glucopyranoside (8), and methyl 3,4,6-tri-O-benzoyl-β-d-glucopyranoside (12), respectively. By virtue of the concerted 1,2-cis α-directing action induced by the 3-O-allyl and 4,6-O-benzylidene groups in donor 2 with a C-2 acetyl group capable of neighboring-group participation, the couplings were achieved with a high degree of α selectivity. In particular, higher α/β stereoselective galactosylation (5.0:1.0) was noted in the case of the coupling of donor 2 with acceptor 12 having a β-CH3 at C-1 and benzoyl groups at C-4 and C-6. 相似文献
3.
Reaction of trifluoro(fluoroxy)methane at ca. −80° with 3,4,6-tri-O-acetyl-D-galactal affords trifluoromethyl 3,4,6-tri-O-acetyl-2-deoxy-2-fluoro-α-D-galactopyranoside (2, 39%), 3,4,6-tri-O-acetyl-2-deoxy-2-fluoro-α-D-galactopyranosyl fluoride (3, 37%), trifluoromethyl 3,4,6-tri-O-acetyl-2-deoxy-2-fluoro-α-D-talopyranoside (4, 3%), and 3,4,6-tri-O-acetyl-2-deoxy-2-fluor-α-D-talopyranosyl fluoride (5, 2%). The structures of compounds 2–5 have been established by n.m.r. spectroscopy. Acid hydrolysis of 2 or 3 allords 2-deoxy-2-fluoro-D-galactose. 相似文献
4.
M. R. Aouad 《Nucleosides, nucleotides & nucleic acids》2016,35(1):1-15
The solvent-free 1,3-dipolar cycloaddition reaction of dimethylacetylene dicarboxylate (1) with 2-chlorophenyl azide (2) afforded 1,2,3-triazole diester 3 that upon hydrazinolysis, furnished the corresponding bis-acid hydrazide 4. The treatment of compound 4 with carbon disulfide in a refluxing potassium hydroxide solution furnished the desired bis-1,3,4-oxadiazole-2-thione 5 tethered to a 1,2,3-triazole moiety. The respective SOx-glycosides 9–11 were obtained by glycosylation of bis-oxadiazole 5 with 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide (6), 2,3,4,6-tetra-O-acetyl-α-d-galactopyranosyl bromide (7), and 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-d-glucopyranosyl chloride (8) in dry acetone in the presence of Et3N, which acted as a base. However, alkylation of 5 with halogeno-alkanol 12 or 13, chloroglycerol 14, bromoethers 20 or 21, and epichlohydrin 22 in the presence of K2CO3 in DMF yielded the corresponding acyclonucleoside analogs 16–18 and 23–25. The isopropylidenes 19 and acetyl derivatives 26–28 of the products were also prepared. The newly synthesized compounds were characterized by 1H NMR, 13C NMR, 2D NMR, and mass spectra. The compounds were screened for their antibacterial and antifungal activities. A number of the tested compounds exhibited significant antimicrobial activity compared to the reference drugs. 相似文献
5.
Lydmila D. Garaeva Irina V. Yartseva Stalina Ya. Melnik 《Nucleosides, nucleotides & nucleic acids》2013,32(6):1295-1303
Abstract A synthesis of 4,6-dimethylthio-1-(2-deoxy-β-D-erythro-pentofuranosyl)pyrazolo[3,4-d]pyrimidine-3-carbonitrile (4) is described using the stereospecific sodium salt glycosylation procedure. Condensation of the sodium salt of 4,6-dimethylthiopyrazolo[3,4-d]pyrimidine-3-carbonitrile (1) with 1-chloro-2-deoxy-3,5-di-O-p-toluoyl-α-D-eythro-pentofuranose (2) gave exclusively the corresponding blocked nucleoside (3) with β-anomeric configuration, which on deprotection provided 2′-deoxyriboside 4. Aglycone functional groups transformations of 4 led to related 3,4,6-trisubstituted pyrazolo[3,4-d]pyrimidine-2′-deoxynucleosides. These compounds are devoid of any significant cytotoxic activity in vitro. 相似文献
6.
《Chemical Speciation and Bioavailability》2013,25(2):133-146
AbstractA new series of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Sr(II), Hg(II), Ag(I), Tl(I) and UO2(II) complexes of 2-(2-(4-carboxyphenyl)guanidino)acetic acid ligand have been synthesised and characterised by elemental analyses, IR, UV-Vis spectra, mass spectra (ligand and its zinc(II) complex), 1H NMR spectra (ligand and its mercury(II) complex), magnetic moments, conductances, thermal analyses (DTA and TGA) and ESR measurements. The IR data show that, the ligand behaves as neutral tridentate, (2), [(H2 LL)3 CCu2 ((OAc)4 ((H2 OO)2 ] ], neutral bidentate, (3), [(H2LL)Cu(OAc)2]].1/2H2OO, (13), [(HL)2CCuCl2((H2OO)2]], (17), [(H2LL)Cu(OOSO2))(H2OO)J,dibasic hexadentate, (4), [(L) Ni4((OAc)6((H2OO)J.4H2OO, (5), [(L)Mn4(OAc)6(H2O)10]. 4H2O, (6), [(L)Co4(OAc)6(H2O)10] . 4H2O, monobasic bidentate, (7), [(HL)(UO2)(OAc)(H2O)3], (12), [(HL)2Cu], (15), [(HL)2Fe2(Cl4)(H2O)2]. 7H2O, (16), [(HL)2Cr2(Cl4)(H2O)2]. 7H2O, (21 ), [(H2L)Cd (OOSO2)(H2O)3]. 2H2O, monobasic tridentate, (8), [(L)2HHg2((OAc)2 (H2O)6].H2O, (9), [(L)2Zn2(OAc)2(H2O)6].H2O, (10), [(L) 2ZZn2((OAc)2((H2OO)6]].H2OO, (11), [(L)Tl4(OAc)3 (H2O)6], (18), [(HL)(OH)Cr2(SO4)2(H2O)5]. H2O, (19), [(HL)3Ag3NO3], or dibasic tridentate, (14), [(L) Sr(Cl)20 ((H2 OO)24 ]], (20), [(L)3 CCu (H2 OO)2 ] ]. Molar conductances in DMF indicate that, the complexes are non-electrolyte. The ESR spectra of Cu(II) complexes (2), (3) and (20) at room temperature show axial type symmetry with g// > g-> 2.00, indicating a d(x2-y2) ground state with significant covalent bond character in an octahedral or square planar geometry. However, Cu(II) complexes (12) and (13) show isotropic type, indicating square planar and octahedral structure. Complexes Mn(II) (5) and Co(II) (6) show broad signals in the low field region indicating spin exchange interaction take place between metal(II) ion. Hg(II) complex (9), Tl(I) complex (11), Cr(III) complex (16), Cu(II) complex (17) and Cd(II) complex (21) showed potential antiproliferative activity where they showed inhibitory effect on breast carcinoma (MCF-7 cell line) in comparing with the standard drug. 相似文献
7.
为了解华石斛(Dendrobium sinense)的化学成分,采用多种柱色谱技术从其全草乙醇提取液中分离纯化了10个化合物,经波谱分析分别鉴定为:鼓槌石斛素(1)、2′,4′-二羟基查尔酮(2)、2,5,7-三羟基-4-甲氧基-9,10-二氢菲(3)、4,7-二羟基-2,3-二甲氧基-9,10-二氢菲(4)、2,5-二羟基-3,4-二甲氧基-9,10-二氢菲(5)、2,7-二羟基-3,4,6-三甲氧基-9,10-二氢菲(6)、(E)松柏醛(7)、反式对羟基肉桂酸酯(8)、对羟基苯丙酸甲酯(9)和十二元内环酯(10)。所有化合物均为首次从华石斛中分离得到,其中化合物2、6、7和10对乙酰胆碱酯酶具有一定的抑制活性。 相似文献
8.
Mina A. Nashed 《Carbohydrate research》1979,71(1):299-304
2-Methyl-(3,4,6-tri-O-benzoyl-1,2-dideoxy-α-d-galactopyrano)-[2′,1′:4,5]-2-oxazoline (7) was prepared from 1-propenyl 2-acetamido-3,4,6-tri-O-benzoyl-2- deoxy-β-d-galactopyranoside (6). The latter was prepared from allyl 2-acetamido-2-deoxy-β-d-glucopyranoside (1) through selective benzoylation at O-3 and O-6, conversion into the 4-p-bromobenzenesulfonate 4, inversion of configuration at C-4 to afford allyl 2-acetamido-3,4,6-tri-O-benzoyl-β-d-galactopyranoside (5), and subsequent isomerization with palladium-charcoal to give 6. 相似文献
9.
Raymond J. Bergeron Jan Wiegand Neelam Bharti James S. McManis Shailendra Singh 《Biometals》2011,24(2):239-258
The current solution to iron-mediated damage in transfusional iron overload disorders is decorporation of excess unmanaged
metal, chelation therapy. The clinical development of the tridentate chelator deferitrin (1, Table 1) was halted due to nephrotoxicity. It was then shown by replacing the 4′-(HO) of 1 with a 3,6,9-trioxadecyloxy group, the nephrotoxicity could be ameliorated. Further structure–activity relationship studies
have established that the length and the position of the polyether backbone controlled: (1) the ligand’s iron clearing efficiency
(ICE), (2) chelator tissue distribution, (3) biliary ferrokinetics, and (4) tissue iron reduction. The current investigation
compares the ICE and tissue distribution of a series of (S)-4,5-dihydro-2-[2-hydroxy-4-(polyether)phenyl]-4-methyl-4-thiazolecarboxylic acids (Table 1, 3–5) and the (S)-4,5-dihydro-2-[2-hydroxy-3-(polyether)phenyl]-4-methyl-4-thiazolecarboxylic acids (Table 1, 8–10). The three most effective polyether analogues, in terms of performance ratio (PR), defined as mean ICEprimate/ICErodent, are 3 (PR 1.1), 8, (PR 1.5), and 9, now in human trials, (PR 2.2). At the onset of the clinical trial on 9, no data were available for ligand 3 or 8. This is unfortunate, as 3 has many advantages over 9, e.g., the ICE of 3 in rats is 2.5-fold greater than that of 9 and analogue 3 achieves very high levels in the liver, pancreas, and heart, the organs most affected by iron overload. Finally, the impact
of 3 on the urinary excretion of kidney injury molecule-1 (Kim-1), an early diagnostic biomarker for monitoring acute kidney toxicity,
has been carried out in rats; no evidence of nephrotoxicity was found. Overall, the results suggest that 3 would be a far superior clinical candidate to 9. 相似文献
10.
Natalia Kleczewska Piotr Ruszkowski Aleksandra Singh Roksana Trznadel 《Nucleosides, nucleotides & nucleic acids》2013,32(9):605-641
AbstractA series of novel 4-chlorophenyl N-alkyl phosphoramidates of 3′-[4-fluoroaryl-(1,2,3-triazol-1-yl)]-3′-deoxythymidines (20–49) was synthesized by means of phosphorylation of 3′-[4-aryl-(1,2,3-triazol-1-yl)]-3′-deoxythymidines (7–11) with 4-chlorophenyl phosphoroditriazolide (14), followed by a reaction with the appropriate amine. The synthesized compounds 7–11 and 20–49 were evaluated along with four known anticancer compounds for their cytotoxic activity in human cancer cell lines: cervical (HeLa), nasopharyngeal (KB), breast (MCF-7), osteosarcoma (143B) (only selected compounds 20, 24, 28, 32–36, 38, 40, 46) and normal human dermal fibroblast cell line (HDF) using the sulforhodamine B (SRB) assay. Among 3′-[4-aryl-(1,2,3-triazol-1-yl)]-3′-deoxythymidines (7–11) the highest activity in all the investigated cancer cells was displayed by 3′-[4-(3-fluorophenyl)-(1,2,3-triazol-1-yl)]-3′-deoxythymidine (9) (IC50 in the range of 2.58–3.61?μM) and its activity was higher than that of cytarabine. Among phosphoramidates 20–49 the highest activity was demonstrated by N-n-propyl phosphoramidate of 3′-[4-(3-fluorophenyl)-(1,2,3-triazol-1-yl)]-3′-deoxythymidine (35) in all the cancer cells (IC50 in the range of 0.97–1.94?μM). Also N-ethyl phosphoramidate of 3′-[4-(3-fluorophenyl)-(1,2,3-triazol-1-yl)]-3′-deoxythymidine (33) exhibited good activity in all the used cell lines (IC50 in the range of 4.79–4.96?μM). 相似文献
11.
Anna S. Efremova Alexandra L. Zakharenko Stanislav I. Shram Irina V. Kulikova Mikhail S. Drenichev Maria V. Sukhanova 《Nucleosides, nucleotides & nucleic acids》2013,32(9):510-528
Nearly 30 synthetic nucleosides were tested with human recombinant poly(ADP-ribose) polymerase 1 as potential inhibitors of this enzyme. The most active compounds were some disaccharide analogues of thymidine: 3′-O-β-D-ribofuranosyl-5-iodo-dUrd (2d; IC50 = 45 μM), 3′-O-β-D-ribofuranosyl-2′-deoxythymidine (2e; IC50 = 38 μM), and 3′-O-β-D-ribofuranosyl-2′-deoxythymidine oxidized (4; IC50 = 25 μM). These compounds also reduced H2O2-induced synthesis of poly(ADP-ribose) in cultured human ovarian carcinoma (SKOV-3) cells in a dose-dependent manner. Furthermore, compounds 2d or 2e until a concentration of 1 mM did not affect growth of SKOV-3 cells, whereas dialdehyde compound 4, as well as thymidine, exhibited a significant cytotoxicity. 相似文献
12.
The synthesis is described of the glycotripeptide derivatives 2-acetamido-3,4,6-tri-O-acetyl-N-[N-(benzyloxycarbonyl)-L--seryl-L-nitroarginyl-L-aspart-4-oyl]-2-deoxy-β-D-glucopyranosylamine, 2-acetamido-3,4,6-tri-O-acetyl-N-[N-(benzyloxycarbonyl)-L-seryl-L-nitroarginyl-L-aspart-1-oyl-(1-p-nitrobenzyl ester)-4-oyl]-2-deoxy-β-D-glucopyranosylamine, and 2-acetamido-3,4,6-tri-O-acetyl-N-[N-(benzyloxycarbonyl)-L-nitroarginyl-L-aspart-1-oyl-(L-leucine methyl ester)-4-oyl]-2-deoxy-β-D-glucopyranosylamine, and of the glycopentapeptide and glycohexapeptide derivatives 2-acetamido-3,4,6-tri-O-acetyl-N-[N-(benzyloxycarbonyl)-L-nitroarginyl-L-aspart-1-oyl-(L-leucyl-L-threonyl-threonyl-Nε-tosyl-L-lysine-(p-nitrobenzyl ester)-4-oyl]-2-deoxy-β-D-glycopyranosylamine and 2-acetamido-3,4,6-tri-O-acetyl-N-[N-(benzyloxycarbonyl)-L-nitroarginyl-L-aspart-1-oyl-(L-leucyl-L-threonyl-Nε-tosyl-L-lysyl-L-aspartic 1,4-di-p-nitrobenzyl ester)-4-oyl]-2-deoxy-β-D-glucopyranosylamine. 相似文献
13.
Elumalai Kumaran Meenakshisundaram Santhi Kalpattu K. Balasubramanian Shanmugasundaram Bhagavathy 《Carbohydrate research》2011,(13):1654
Montmorillonite K-10 clay-catalyzed substitution reactions of 3,4,6-tri-O-alkyl-2-C-hydroxymethyl-d-glycals, 3,4,6-tri-O-acetyl-d-glycals, 3,4,6-tri-O-alkyl-d-glycals, and 3,4-(dihydro-2H-pyran-5-yl)methanol with a few alcohols and phenols are described. The reactions of 2-C-hydroxymethyl-d-glycals with phenols were similar to those of 2-C-acetoxymethyl-d-glycals and afforded pyrano[2,3-b]benzopyrans. This montmorillonite K-10 clay-catalyzed transformation is facile both under ambient (Method 1) and microwave conditions (Method 2). Ferrier rearrangement of 3,4-(dihydro-2H-pyran-5-yl)methanol with p-cresol, 2,6-xylenol, and ethanol led to totally unexpected transformations. Reaction of 2-C-hydroxymethyl-d-galactal with 2,6-dimethylphenol in the presence of montmorillonite K-10 led to a novel domino transformation affording 4-(5′,6′-dihydro-4H-pyran-3′-ylmethyl)-2,6-dimethylphenol. In contrast, 3,4,6-tri-O-acetyl-d-glucal furnished the Ferrier rearrangement product, 2,6-dimethylphenyl 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside. Also, isomerization of 3,4,6-tri-O-alkyl-d-glycals to products of allylic rearrangement, 2,3-unsaturated-O-glycosides in good yields is reported. 相似文献
14.
Three related pairs of diastereoisomers, the previously unknown 3,4,6-tri-O-acetyl-1,2-O-ethylidene- and 3-O-acetyl-1,2:4,6-di-O-ethylidene-α-d-glucopyranoses, and the known 3,4,6-tri-O-acetyl-1,2-O-benzylidene-α-d-glucopyranose, were prepared by reduction of intermediate dioxolenium chloride ions with sodium borohydride. Each pair of isomers was separated into its components by preparative t.l.c. Four correlations of n.m.r. parameters with dioxolane configuration were used to assign the structure of each isomer of a diastereoisomeric pair: (1) Deshielding of the 2′-substituent when endo: (2) deshielding of H-2 or H-5 by bulky exo or endo 2′-substituents; (3) larger values of J2,3 and J3,4 when a bulky 2′-substituent has an exo orientation; and (4) the presence of long-range (4J) coupling of H-2 and H-4 of the pyranose ring only in molecules with a bulky 2′-substituent in an endo orientation. The degree to which the pyranose ring is distorted by the cis-fusion of a dioxolane ring in such derivatives, as well as by endo phenyl, methyl, and proton substituents, is evaluated. 相似文献
15.
Kazuhiro Haraguchi Masanori Sumino Hiromichi Tanaka 《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):835-839
For the synthesis of 2′,3′ -didehydro-3′ -deoxy-4′ -C-ethynylthymidine (8: 4′ -Ed4T), a recently reported promising anti-HIV agent, a new approach was developed. Since treatment of 1-(2,5-dideoxy-β-l-glycero-pent-4-enofuranosyl)thymine with Pb(OBz)4 allowed the introduction of a 4′-benzoyloxy leaving group, nucleophilic substitution at the 4′ -position became feasible for the first time. Thus, reaction between the 4′-benzoyloxy derivative (11) and Me3SiC ≡ CAl(Et)Cl as a nucleophile led to the isolation of the desired 4′-“down”-ethynyl derivative (15) stereoselectively in 62% yield. 相似文献
16.
Darren Griffith Sara Cecco Ennio Zangrando Alberta Bergamo Gianni Sava Celine J. Marmion 《Journal of biological inorganic chemistry》2008,13(4):511-520
Reaction of 3-pyridinehydroxamic acid and 4-pyridinehydroxamic acid (3-pyha and 4-pyha) with either [NBu4][RuCl4(dmso-S)2] or [(dmso)2H][RuCl4(dmso-S)2] (dmso is dimethyl sulfoxide) in acetone afforded three new ruthenium(III) dimethyl sulfoxide pyridinehydroxamic acid complexes:
[NBu4][trans-RuCl4(dmso-S)(4-pyha)]·CH3COCH3 (1), [3-pyhaH][trans-RuCl4(dmso-S)(3-pyha)] (2) and [4-pyhaH][trans-RuCl4(dmso-S)(4-pyha)] (3). The solid-state structure of [NBu4][trans-RuCl4(dmso-S)(4-pyha)]·CH3COCH3 (1) was determined by X-ray crystallography. 2 and 3 were pharmacologically evaluated for their in vitro cytotoxicity, their ability to inhibit cell invasion and their gelatinase
activity. 2 and 3 were devoid of cytotoxicity against the cell lines tested. 2 inhibited invasion of the highly invasive MDA-MB-231 cells to a much greater extent than 3. Contrary to expectations, neither 2 nor 3 had any inhibitory effect on matrix metalloproteinase (MMP) production and/or activity and in fact 3 was found to enhance the production and/or activity of both MMP-2 and MMP-9. 相似文献
17.
Khodayar Gholivand Mohammad Abdollahi Fresia Mojahed Ahlam Madani Alizadehgan Gholamreza Dehghan 《Journal of enzyme inhibition and medicinal chemistry》2013,28(2):566-576
Eight newly synthesized carbacylamidophosphates with the general formula RC(O)NHP(O)Cl2 with R = pCl–C6H4 1a, pBr–C6H4 2a, C6H5 3a, and pMe–C6H4 4a and RC(O)NHP(O)(NC4H8O)2 R = pCl–C6H4 1b, pBr–C6H4 2b, C6H5 3b, pMe–C6H4 4b, were selected to compare the inhibition kinetic parameters, IC50, Ki, kp and KD, on human erythrocyte acetylcholinesterase (hAChE) and bovine serum butyrylcholinesterase (BuChE), Also, the in vivo inhibition potency of compound 2a, 2b and 3a, were studied. The data demonstrates that compound 2a and compound 2b are the potent sensitive as AChE and BuChE inhibitors respectively, and the inhibition of hAChE is about 10-fold greater than that of BuChE. 相似文献
18.
Sayeda S. Mohamed Abeer A. El-Hadi Khadiga M. Abo-Zied 《Biocatalysis and Biotransformation》2017,35(3):215-222
Prednisolone, a synthetic adrenal corticosteroid drug, is known to have anti-inflammatory and autoimmune activity. Biotransformation of prednisolone was carried out to obtain more bioactive prednisolone derivatives. Among six different fungi, Penicillium aurantiacum proved to be the best prednisolone hydroxylator. As a result of prednisolone biotransformation by P. aurantiacum, whole cells four different prednisolone derivatives were investigated. 20β-Hydroxyprednisolone (1) and 21,21-dimethoxy-11β-hydroxypregn-1,4-dien-3,20-dione (2) were detected as the main metabolites. These metabolites together with other two metabolites, 11β-hydroxyandrost-1,4-dien-3,17-dione (3) and 11β,17β-dihydroxyandrost-1,4-dien-3- one (4), were purified and assigned by an interpretation of their spectral data using mass spectroscopy (MS), proton nuclear magnetic resonance (1H-NMR), carbon nuclear magnetic resonance (13C-NMR) and infrared spectroscopy (IR) analyses. The best fermentation conditions for production of compounds 1–4 were as follows: medium (3) consisting of (g/l): glucose 20; l-asparagine 0.7; MgSO4.7H2O 0.5; KH2PO4 1.52; KCl 0.52; Cu (NO3)2 traces; ZnSO4.7H2O traces, supplemented with prednisolone concentration of 0.3?mg/ml, inoculated by 10% of microorganism and incubated for 72?h. Under these optimized conditions, ~94.8% of the added prednisolone was converted to aforementioned derivatives, which have the potential to be used in industrial production of important pharmaceutical compounds. 相似文献
19.
PurposeThe aim was to measure the cardiac motion-induced displacements of major coronary artery bifurcations utilizing electrocardiography (ECG)-gated four-dimensional computed tomography (4D-CT) and to determine the margin of coronary artery bifurcations.MethodsThirty-seven female patients who underwent retrospective ECG-gated 4D-CT in inspiratory breath hold (IBH) were enrolled. The left main coronary artery bifurcation (LM), the obtuse marginal branch bifurcation (OM), the first diagonal branch bifurcation (D1), the second diagonal branch bifurcation (D2), the caudal portion of the left anterior descending branch (APX), the first right ventricular artery bifurcation (V) and the acute marginal branch bifurcation (AM) were contoured. The center of the contour of the coronary arterial bifurcations at end systole was defined as the standard, and the margin were then calculated.ResultsThe margin in the left–right (LR), cranio-caudal (CC), and anterior-posterior (AP) coordinates were as follows: LM 3, 3, and 3 mm; D1 6, 3, and 3 mm; D2 3, 3, and 3 mm; APX 4, 4, and 4 mm; OM 4, 6, and 5 mm; V 6, 8, and 7 mm; and AM 6, 8, and 7 mm, respectively.ConclusionCoronary artery bifurcations should be considered a separate organ at risk (OAR), and different margin should be provided due to the differences resulting from motion displacement. The maximum margin in the LR, CC, and AP coordinates of left coronary artery bifurcations were 6, 6, and 5 mm, and those of the right coronary artery bifurcations were 6, 8, and 7 mm, respectively. 相似文献
20.
The behavior of the acetamido (and benzamido) ambident, nucleophilic group under methylation with methyl iodide and silver oxide has been studied for several 2-acetamido-2-deoxy-D-glucose derivatives. When silver perchlorate was added, alkylation occurred at the oxygen atom, giving methyl imidates that were labile in acidic medium. Benzyl 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranoside was converted into N-(benzyl 3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranoside-2-yl) methyl acetimidate (83%), which was subsequently hydrolyzed quantitatively in acidic medium into the corresponding amine salt. Similar results were obtained with benzyl 3,4,6-tri-O-acetyl-2-benzamido-2-deoxy-β-d-glucopyranoside, methyl 2-acetamido-2-deoxy-3,4,6-tri-O-methyl-β-D-glucopyranoside, and benzyl 2-acetamido-3,4,6-tri-O-benzyl-2-deoxy-β-D-glucopyranoside. Under Kuhn's methylation conditions (methyl iodide-silver oxide-N,N-dimethylformamide), alkylation of the just mentioned derivatives occurred at both oxygen and nitrogen atoms. 相似文献