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1.
目的 对(2S,3R)- 1-二甲氨基-3-(3-甲氧基苯基)-2-甲基戊-3-醇合成工艺进行研究.方法 以3-戊酮为起始原料,经Mannich反应、手性拆分、Grignard反应等步骤合成(2S,3R)-1-二甲氨基-3-(3-甲氧基苯基)-2-甲基戊-3-醇,并对化学拆分进行工艺优化.结果 合成(2S,3R)-1-二甲氨基-3-(3-甲氧基苯基)-2-甲基戊-3-醇,总收率为30.6%.结论 工艺改进后提高了目标产物的收率,同时也减少了原料的浪费. 相似文献
2.
(-)-(S)-Brevicolline (1) and related beta-carbolines were synthesized using an enantiomerically pure Michael-acceptor synthon (3). Subsequent Pictet-Spengler reaction afforded the tetrahydro-beta-carboline skeleton, which, in turn, was transformed to the beta-carboline by catalytic dehydrogenation. 相似文献
3.
Ishii H Krane S Itagaki Y Berova N Nakanishi K Weldon PJ 《Journal of natural products》2004,67(8):1426-1430
Pelage extracts of the banteng (Bos javanicus), the domestic cattle (B. taurus), the gaur (B. frontalis), and the yak (B. grunniens) were investigated by FABMS and NMR. An 18-carbon hydroxyfuranoid acid, 1 (10-hydroxy-6,9-oxidooctadecanoic acid), first reported from the wool of the domestic sheep (Ovis aries) was confirmed in B. frontalis; we suspend judgment on the occurrence of this compound in the other species we examined. The stereochemistry of 1, determined by Mosher NMR and CD tweezer methods, was assigned as 6S, 9R, 10R. We propose the name bovidic acid for this and homologous alpha-hydroxylated 2,5-tetrahydrofuranoid carboxylic acids, in reference to the family Bovidae, which represents their sole known natural source. 相似文献
4.
(+/-)-Norarmepavine [3] [corrected] prepared by Bischler-Napieralski synthesis afforded, on reaction with (S)-(-)-1-phenylethylisocyanate, ureas 4 and 5 which were separated and purified by crystallization from EtOH and 70% HOAc. Alcoholysis of 4 and 5 with sodium butoxide in n-BuOH afforded (S)-norarmepavine [3a] and (R)-norarmepavine [3b] [corrected], respectively. Hplc analysis of ureas prepared from 3a and 3b with (S)-(-)-1-phenylethylisocyanate showed them to be optically pure alkaloids. Refluxing 3a and 3b with 48% HBr afforded the hydrobromide salts of (S)-norcoclaurine [1a] and its (R)-isomer 1b, respectively. 相似文献
5.
目的 合成罗替戈汀关键手性中间体S(-)2-(N-正丙基)胺基-5-甲氧基四氢萘.方法 以5-甲氧基-2-四氢萘酮为起始物,经过正丙胺胺化、10%钯炭催化氢化还原、手性拆分3个步骤合成得到该中间体.结果手性中间体S(-)2-(N-正丙基)胺基-5-甲氧基四氢萘的总收率为21.5%.结论该路线的原料廉价易得、收率高,适合罗替戈汀的关键手性中间体S(-)2-(N-正丙基)胺基-5-甲氧基四氢萘的工业化生产. 相似文献
6.
El Sayed KA Laphookhieo S Yousaf M Prestridge JA Shirode AB Wali VB Sylvester PW 《Journal of natural products》2008,71(1):117-122
Tobacco-derived (1 S,2 E,4 S,6 R,7 E,11 E)-2,7,11-cembratriene-4,6-diol (1) and (1 S,2 E,4 R,6 R,7 E,11 E)-2,7,11-cembratriene-4,6-diol (2) were first shown to display potential antitumor-promoting activity in the mid-1980s. However, very little is currently understood regarding the structural activity relationships of tobacco cembranoids. The aim of this present study was to explore antiproliferative activity of various derivatives of (1 S,2 E,4 S,6 R,7 E,11 E)-2,7,11-cembratriene-4,6-diol (1) using semisynthetic and biotransformation approaches. Derivatives of 1 include esterified, oxidized, halogenated, and nitrogen- and sulfur-containing compounds (3-17). Biotransformation of 1 using Mucor ramannianus ATCC 9628 and Cunninghamella elegans ATCC 7929 afforded the known 10 S,11 S-epoxy analogue of 1 (4) as the main metabolite. Biotransformation of the 6-O-acetyl analogue (3) using the marine symbiotic Bacillus megaterium strain MO31 afforded (1 S,2 E,4 S,6 R,7 E,11 E,10 R)-2,7,11-cembratriene-4,6,10-triol (18). (1 S,2 E,4 S,6 R,7 E,11 E,13 R)-2,7,11-Cembratriene-4,6,13-triol-6-O-acetate (6), (1 S,2 E,4 S,6 R,7 E,11 E,13 S)-2,7,11-cembratriene-4,6,13-triol-6-O-acetate (7), the rearranged alpha-ketol (1 S,2 E,4 S,7 Z,11 E)-2,7,11-cembratrien-4-ol-6-one (11), and the secocembranoid 12 showed antiproliferative activity against highly malignant +SA mammary epithelial cells with an IC50 range of 15-30 microM. 相似文献
7.
Costes N Michel S Tillequin F Koch M Pierré A Atassi G 《Journal of natural products》1999,62(3):490-492
Sharpless asymmetric dihydroxylation of acronycine (1) gave (1R, 2R)-1,2-dihydroxy-1,2-dihydroacronycine (2) and (1S,2S)-1, 2-dihydroxy-1,2-dihydroacronycine (3), which allowed determination of the absolute configuration of natural cis-1,2-dihydroxy-1, 2-dihydroacronycine as 1R,2R. The cis isomer had been previously isolated from various Sarcomelicope species. Benzylic reduction of isomers 2 and 3 gave the alcohols 4 (2R) and 5 (2S), respectively. Acetylation of 2 and 3 afforded the corresponding esters 6 and 7. No significant difference of cytotoxicity was observed between these (1R,2R)- and (1S,2S)-enantiomers and the recently described, highly active racemic cis-1,2-diacetoxy-1,2-dihydroacronycine, when tested against L-1210 cells in vitro. 相似文献
8.
目的:探讨3'-乙酰氧基被N-7亲核试剂取代的反应条件、分离精制方法和新头孢菌素的体外抗菌活性。方 法:7-(香豆素-3-甲酰胺)头孢菌素在Nal或KSCN的存在下与吡啶和β-甲基吡啶反应,产物用大孔吸附树脂及葡 聚糖凝胶柱层析分离。结果:合成的二个新头孢菌素化合物,由红外光谱、元素分析和核磁共振谱确证其化学结构。体外抗菌试验表明,对某些革兰阴性菌有一定的抑菌作用。结论:该反应中加入大量的Nal可缩短短反应时间并减少杂质。大孔吸附树脂可有效果将头孢菌素与无机盐分离。 相似文献
9.
目的:探讨3'-乙酰氧基被N-亲核试剂取代的反应条件、分离精制方法和新头孢菌素的体外抗菌活性。方法:7-(香豆素-3-甲酰胺)头孢菌素在NaI或KSCN的存在下与吡啶和β-甲基吡啶反应,产物用大孔吸附树脂及葡聚糖凝胶柱层析分离。结果:合成的二个新头孢菌素化合物,由红外光谱、元素分析和核磁共振谱确证其化学结构。体外抗菌试验表明,对某些革兰阴性菌有一定的抑菌作用。结论:该反应中加入大量的NaI可缩短反应时间并减少杂质。大孔吸附树脂可有效地将头孢菌素与无机盐分离。 相似文献
10.
The total synthesis of (-)-julocrotine (1) starting from l-glutamic acid in 41% overall yield is described. The methodology utilizes protection, deprotection, and regioselection (carbonyl differentiation via oxazolidinone) protocols, and glutarimide ring formation is the key step. 相似文献
11.
Devijver C Salmoun M Daloze D Braekman JC De Weerdt WH De Kluijver MJ Gomez R 《Journal of natural products》2000,63(7):978-980
The Caribbean marine sponge Haliclona vansoesti was found to contain a high amount (5% dry wt) of a new analogue of 4-sphingenine, (2R,3R, 7Z)-2-aminotetradec-7-ene-1,3-diol (1). Its structure was determined by detailed spectroscopic analysis. The relative configuration was deduced from the NMR data of the corresponding acetonide 5, while the absolute configuration was secured via protection of the primary alcohol and amino groups, and esterification of the secondary alcohol with Mosher's reagent. 相似文献
12.
The synthetic (E)-isomer (3b) of natural combretastatin A-1 (1a) isolated from the African bushwillow Combretum caffrum was the focus of chiral hydroxylation (Sharpless) reactions as part of a structure-activity relationship study. The resulting (R,R)- and (S,S, )-diols (6 and 7) and synthetic intermediates were evaluated against a series of cancer cell lines, microorganisms, and tubulin. Chiral diols 6 and 7 showed increased activity against the P-388 murine lymphocytic leukemia cell line with ED(50) values of 3.9 and 2.9 microg/mL, respectively, when compared to the precursor (E)-stilbene 3b. In contrast, (E)-stilbene 3b exhibited more potent antibiotic activity than the chiral diols (6 and 7). Both diols, (R,R)-6 and (S, S)-7, displayed less cancer cell growth inhibition and less antibiotic activity than did natural combretastatin A-1 (1a) (P-388 ED(50) 0.25 microg/mL). 相似文献
13.
目的研究生物不对称催化苯乙酮酸合成手性药物前体R(-)-扁桃酸。方法通过对本实验室保存的12株酵母菌进行初筛,获得对底物苯乙酮酸具有较高催化活性的菌株S.c.1,S.c.3和S.c.10。进一步对其进行紫外与微波诱变,得到R(-)-扁桃酸高产菌株S.c.10.2.8。结果在转化培养中,初始底物浓度为20mmol·L-1,pH6.6,温度34℃,R(-)-扁桃酸得率85%,对映体过量值(e.e)>99%。结论生物转化法在生产手性药物前体R(-)-扁桃酸中前景广泛。 相似文献
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15.
The synthesis of sodium narcistatin (8) was improved (88% overall yield) and the modified reaction sequence was utilized to synthesize three new 3,4-cyclic phosphate prodrugs, sodium 7-deoxynarcistatin (5), sodium 7-deoxy-trans-dihydronarcistatin (6), and sodium trans-dihydronarcistatin (7). The human cancer cell line inhibitory isocarbostyril precursors were isolated from the bulbs of Hymenocallis littoralis obtained by horticultural production or reduction of narciclasine (1a --> 4) from the same source. 相似文献
16.
目的:优化板蓝根中(R,S)-告依春的提取方法。方法:采用薄层色谱法和高效液相色谱法比较了水、80%甲醇为溶剂超声、水煮提3种不同提取方法对(R,S)-告依春的影响。结果:最佳提取条件为:水为溶剂,超声处理。结论:优化的提取方法简单快速,结果准确。 相似文献
17.
Kossuga MH MacMillan JB Rogers EW Molinski TF Nascimento GG Rocha RM Berlinck RG 《Journal of natural products》2004,67(11):1879-1881
A new antifungal agent, (2S,3R)-2-aminododecan-3-ol (1), has been isolated from the ascidian Clavelina oblonga collected in Brazil. The structure of 1 was established by analysis of spectroscopic data, including absolute stereochemistry determined by circular dichroism analysis of the dibenzoyl derivative 2. Compound 1 displayed antifungal activity against Candida albicans ATCC 10231 with a MIC of 0.7 mug/mL and against Candida glabrata with a MIC of 30 microg/mL. 相似文献
18.
20-(S)和20-(R)人参皂苷Rg2对心源性休克犬血流动力学和血氧含量的影响 总被引:7,自引:0,他引:7
目的 观察比较 2 0 - ( S)和 2 0 - ( R)人参皂苷 Rg2 ( ginsenoside Rg2 )不同构型对犬急性心源性休克血流动力学和血氧含量的影响。方法 结扎冠状动脉左前降支 ( L AD)造成心源性休克模型 ,分别 iv1mg/ kg的 2 0 - ( S) -人参皂苷 Rg2 ,2 0 - ( R) -人参皂苷 Rg2 、混合型人参皂苷 Rg2 ,观察比较对休克犬血流动力学和血氧含量各项指标的作用。结果 两种不同构型和混合型的人参皂苷 Rg2 ,与溶媒对照组比较 ,对平均动脉压 ( MAP)、左室内压( L VSP)、左室内压最大变化速率 (± dp/ dtmax)均有升高作用 ,增加心输出量 ( CO)、心脏指数 ( CI)、心博指数( SI)、动脉血氧含量、静脉血氧含量。结论 人参皂苷 Rg2 不同构型对犬急性心源性休克均具有较好的治疗作用。两种构型 Rg2 组比较 ,各项指标作用强度无显著差异。 相似文献
19.