共查询到20条相似文献,搜索用时 10 毫秒
1.
Takeshi Kitahara Katsutoshi Miura Yasuhiro Warita Yoshikazu Takagi Kenji Mori 《Bioscience, biotechnology, and biochemistry》2013,77(4):1129-1133
A novel synthesis of ( ± )-methyl epijasomonate (2) and the first synthesis of ( ± )-methyl cucurbate (4) were achieved starting from 2-allylcyclohexane-1,3-dione (8). The synthetic epimer 2 had a stronger jasmin flavor than the trans-isomer 1 with 95% purity. 相似文献
2.
The response surface methodology (RSM) was used to optimize the extraction conditions for the acetylcholinesterase (AchE) inhibitory activity and extraction yield from Camellia japonica seed cake. Predicted values for AchE inhibition and extraction yield were 19.41 and 13.35%, respectively, which are in good agreement with the experimental values from validation, suggesting that RSM may provide a useful tool to optimization processes. 相似文献
3.
Adel M. Attia Galal H. Elgemeie Ibrahim S. Alnaimi 《Nucleosides, nucleotides & nucleic acids》2013,32(8):1355-1363
Abstract The synthesis of new 4- and 5-substituted-3-cyanopyridine nucleosides has been performed by reacting the silylated pyridines and penta-O-acetyl-α -D-glycopyranose in dichloroethane in the presence of SnCl4. The free nucleosides were tested for their potential activity against HIV and different types of tumor. 相似文献
4.
《Inorganica chimica acta》1986,114(2):141-144
The preparations and properties of tris(dipivaloylmethanato)technetium(III), tris(trifluoroacetylacetonato)technetium(III), and tris(hexafluoroacetonato)technetium(III) are described. The oxidation of the dipivaloyl derivative to tris(dipivaloyl)technetium(IV) hexafluorophosphate was shown to take place readily. Voltammetric studies and magnetic resonance results on the new complexes are reported. The large shifts observed for the complexes seem to be due to a contact interaction. 相似文献
5.
(S)-(?)-Vertinolide 1 was synthesized via the tetronic acid derivative 6 from (S)-(?)-tetrahydro-2-methyl-5-oxo-2-furancarboxylic acid 3. (±)-Vertinolide was also synthesized from (±)-3. 相似文献
6.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1671-1674
The synthesis of (±)-methyl bishomononactate, one of the monomeric components of polynactin antibiotics (macrotetrolides), was achieved via cis-selective iodoetherification as the key step. 相似文献
7.
Synthesis and Properties of O-β-D-Ribofuranosyl-(1″-2′)-Adenosine-5″-O-Phosphate and Its Derivatives
Andrei A. Rodionov Ekaterina V. Efimtseva Sergey N. Mikhailov Jef Rozenski Ingrid Luyten Piet Herdewijn 《Nucleosides, nucleotides & nucleic acids》2013,32(10-12):1847-1859
Abstract The synthesis of O-β-D-ribofuranosyl-(1″-2′)-adenosine-5″-O-phosphate and its suitably protected derivative for oligonucleotide synthesis have been developed. 相似文献
8.
Tamizi Sugiyama Hideki Tateba Takeshi Hashizume 《Bioscience, biotechnology, and biochemistry》2013,77(11):2755-2756
The antifungal activity of 22 derivatives of 1-(3,5-dichlorophenyl)-2,5-pyrrolidinedione and 6 derivatives of 3-(3,5-dichlorophenyl)-2,4-oxazolidinedione, having various substituents on the imido rings, against Botrytis cinerea was determined by the agar medium dilution method. The structure-activity relationships were analyzed using the physicochemical parameters of the molecules: such as the hydrophobic log P, the electronic σ*, and the steric Esc values with the multiple regression technique. Only the hydrophobic effect is significant in determining the activity variations of both series of compounds. Furthermore, the structure-activity relationships of these two series of compounds are represented by an identical equation, having only the hydrophobic term as a variable. 相似文献
9.
Abstract The first synthesis of nitro-multideoxy-sugar containing nucleosides was achieved. 1-(4,6-O-Benzylidene-3-deoxy-3-nitro-β-D-glucopyranosyl)uracil (3) was converted in 75% yield into 1-(4,6-O-benzylidene-2,3-dideoxy-3-nitro-arabinohexopyranosyl)uracil (7) by acetylation followed by NaBH4 reduction in methanol. De-O-benzylidenation with CF3CO2H afforded crystalline 1-(2,3-dideoxy-3-nitro-β-D-arabinohexopyranosyl)uracil (S) was obtained in 87% yield. Raney Ni reduction of 8 afforded the corresponding 3′-amino-nucleoside 9. Acetylation of 8 followed by NaBH4 treatment afforded an 8:1 mixture from which 1-(2,3,4-trideoxy-3-nitro-β-D-threohexopyranosyl)-uracil (14) was obtained in pure crystalline form. After Raney Ni reduction of the mixture, 1-(3-amino-2,3,4-trideoxy-β-d-threo-hexopyranosyl)uracil (16) and its erythro epimer 21 were isolated. 1-(4,6-O-Benzylidene-2,3-dideoxy-3-nitro-β-d-lyxohexopyranosyl)uracil (24) was prepared in 72% yield from 1-(4,6-O-benzylidene-3-deoxy-3-nitro-β-d-galactopyranosyl)uracil (4) by acetylation and subsequent reduction with NaBH4. De-O-benzylid-enation of 23 afforded 1-(2,3,4-trideoxy-3-nitro-β-d-lyxohexopyranosyl)uracil (25) in 83% yield. Schmidt-Rutz reaction of 25 followed by NaBH4 reduction afforded a mixture of threo and elythro isomers of 2′,3′,4′-trideoxy-3′-nitro-hexopyranosyluracil, from which pure 16 and 21 were obtained. 相似文献
10.
《Bioscience, biotechnology, and biochemistry》2013,77(9):1386-1391
Bacillus stearothermophilus CGTase had a wider acceptor specificity than Bacillus macerans CGTase did and produced large amounts of transfer products of various acceptors such as D-galactose, D-mannose, D-fructose, D- and L-arabinose, d- and L-fucose, L-rhamnose, D-glucosamine, and lactose, which were inefficient acceptors for B. macerans CGTase. The main component of the smallest transfer products of lactose was assumed to be α-D-glucosyl O-β-D-galactosyl-(l→4)-β-D-glucoside. 相似文献
11.
John A. Secrist III Anita Shortnacy-Fowler L. Lee Bennett Jr. John A. Montgomery 《Nucleosides, nucleotides & nucleic acids》2013,32(5):1017-1029
Abstract A series of 8-substituted purine ribonucleosides were prepared from 2′, 3′, 5′-tri-O-acetyl-8-bromoadenosine and evaluated for cytotoxicity and antiviral activity. Four of these nucleosides (6b-9b) were significantly toxic to both HEp-2 and L1210 cells in culture but the most cytotoxic one (9b) was inactive against the P388 leukemia in mice. None of these nucleosides showed significant antiviral activity against Herpes Simplex 1 or 2, vaccinia, or influenza A. 相似文献
12.
Takashi Kudoh Akira Matsuda Satoshi Shuto Takashi Murayama Yasuo Ogawa 《Nucleosides, nucleotides & nucleic acids》2013,32(4-6):583-599
We previously showed that 3″-deoxy-cyclic ADP-carbocyclic-ribose (3″-deoxy-cADPcR, 3) is a stable and highly potent analogue of cyclic ADP-ribose (cADPR, 1), a Ca2+-mobilizing second messenger. From these results, we newly designed another 3″-modified analogues of cADPcR and identified the N1-“xylo”-type carbocyclic analogue, i.e., cADPcX (4), as one of the most potent cADPR-related compounds reported so far. 相似文献
13.
Kamal N. Tiwari Anita T. Shortnacy-fowler Loredana Cappellacci William B. Parker William R. Waud John A. Montgomery 《Nucleosides, nucleotides & nucleic acids》2013,32(1-2):329-340
Abstract 4′-thio-β-D-arabinofuranosylcytosine was synthesized by a facile route in high yields. It was evaluated for antitumor activity against a panel of human tumors, both in vitro and in vivo. 相似文献
14.
G. Huang 《Journal of enzyme inhibition and medicinal chemistry》2013,28(2):453-456
The synthesis and stability of 4-methylumbelliferyl (1 → 3)-β-D-pentaglucoside 3 are described. The (1 → 3)-β-D-glucan isolated from the cell walls of Saccharomyces cerevisiae was recovered from the aqueous medium as water-insoluble particles by the spray drying (GS) method. The acid-solubilized (1 → 3)-β-D-oligoglucosides were prepared by partial acid hydrolysis of glucan. The peracetylated (1 → 3)-β-D-pentaglucoside 1 was obtained by isolation of peracetylated (1 → 3)-β-D-oligoglucoside mixture. The peracetylated 4-methylumbelliferyl (1 → 3)-β-D-pentaglucoside 2 was synthesized by treating compound 1 with the 4-methylumbelliferone and a Lewis acid (SnCl4) catalyst. NaOMe in dry methanol was used for the deacetylation of the blocked derivative, to give the target compound 3 in an overall yield of 35%. Activity assays with β-glucosidase indicated that compound 3 was much more stable than the corresponding pentasaccharide. 相似文献
15.
Iványi Z Szabó N Huber J Wölfling J Zupkó I Szécsi M Wittmann T Schneider G 《Steroids》2012,77(5):566-574
Various steroidal benzylidenes were synthetized from pregnenolone with benzaldehyde and p-substituted benzaldehydes. The resulting 17β-chalconyl derivatives of pregnenolone were reacted with hydrazine hydrate in acetic acid solution. Regardless of the starting material, the ring-closure reaction afforded (in contrast with the literature data) a mixture of two steroidal pyrazoline epimers. The epimers were critical isomer pairs, which could be separated only in their acetylated form; their structures were investigated by NMR techniques. The in vitro inhibition of rat testicular C(17,20)-lyase activity and the antiproliferative effects on four human cancer cell lines were measured, and the results obtained from the two epimer series were compared. 相似文献
16.
17.
Abstract Oligonucleotide having 2′-5′ phosphodiester linkage has been synthesised on solid support using indigenously prepared 3′-deoxy-2′-phosphoramidites. The 2′-5′ oligonucleotide showed higher half-life when subjected to 3′-exonuclease, SVPD, digestion. This oligonucleotide formed a stable duplex with complementary RNA but not with DNA. Similarly, it did not form triplex as well either with DNA or RNA duplex. 相似文献
18.
Hiroshi Ohrui Tsutami Misawa Hiroshi Meguro 《Bioscience, biotechnology, and biochemistry》2013,77(7):1825-1829
The photobromination of 1,5-anhydro-2,3-O-isopropylidene-β-d-ribofuranose gave the corresponding (5S)-5-bromo compound. The reduction of the bromide with triphenyltindeuteride gave (5S)-(5-2H1)-1,5-anhydro-2,3-O-isopropylidene-β-d-ribofuranose, with a chiral purity of 76% at C-5, which was converted to (5R)- and (5S)-(5-2H1)-d-riboses and other ribofuranose derivatives. 相似文献
19.
Hiroyoshi Omokawa Shin-ichi Kouya Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(2):393-396
A new synthesis of (±)-9-demethylmunduserone (2) is described. Thermal rearrangement of l-(4-benzyloxy-2-hydroxyphenyl)-4-(3′,4′-dimethoxyphenoxy)-2-butyn-1-one (7) afforded 4-(4-benzyloxy-2-hydroxybenzoyl)-6,7-dimethoxy-2H-chromene (8), 3-(4-benzyloxy-2-hydroxyberrzoyl)-5,6-dimethoxy-2-methylbenzofuran (9) and 9-benzyloxy-2,3-dimethoxy-6a,12a-dihydrorotoxen-12(6H)-one (3). 4-Aroyl-2H-chromene (8) was smoothly converted to 3 in quantitative yield by the treatment with sodium acetate. The structure of 3 was confirmed by an alternative synthesis from methyl tephrosate (10). Debenzylation of 3 with aluminum bromide afforded (±)-9-demethylmunduserone (2) in high yield. 相似文献