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1.
H. Tsuchiya M. Sato H. Hayashi H. Kato H. Kureshiro T. Hayashi 《Chromatographia》1996,43(7-8):419-425
Summary Reversed-phase ion-pair HPLC with fluorimetric detectors connected in series was studied for the simultaneous determination of two tetrahydro--carbolines and two -carbolines. After additon of internal standards the samples were reacted with fluorescamine, and then subjected to serial extractions to remove their precursor (tryptamine) from the analytical system. This treatment not only suppressed the artefactual formation of tetrahydro--carbolines and -carbolines during analysis, but also effectively purified them. Under optimum conditions, using trifluoroacetic acid as counter ion, all analytes were separated within 14 min and without major interfering peaks. The quantitative ranges were 0.25–80.0 ng mL–1 for both tetrahydro--carbolines and 0.1–30.0 ng mL–1 for both -carbolines. Replicate spiking experiments showed that recovery from most of the samples tested was over 90% and the relative standard deviation ranged from 0.7 to 10.4% within and between assays. The proposed method was applicable to various materials such as soy sauce, vinegar, ketchup, tabasco, beer, wine, sake, whisky, brandy, cows' milk, coffee, cocoa, cheese, cigarette smoke and urine. 相似文献
2.
Sierra D. Durham Brianna Sierra Maximillian J. Gomez Jennifer K. Tran Marc O. Anderson Nick A. Whittington-Davis Scott Eagon 《Tetrahedron letters》2017,58(28):2747-2750
The oxidation of tetrahydro-β-carbolines to β-carbolines using silver carbonate was developed as an alternative to current methods. The oxidation is extremely mild and provides the products in modest to good yields after purification. A number of functional groups are tolerated by this methodology, including reduction-sensitive groups which are often cleaved with other methods. Though the mechanism is not fully understood, the reaction proceeds in an open flask, is not sensitive to light or moisture, and provides a viable synthetic route to compounds that are not easily prepared via other methodologies. 相似文献
3.
Peter Bernhardt 《Tetrahedron letters》2010,51(33):4400-8564
Strictosidine synthase triggers the formation of strictosidine from tryptamine and secologanin, thereby generating a carbon-carbon bond and a new stereogenic center. Strictosidine contains a tetrahydro-β-carboline moiety—an important N-heterocyclic framework found in a range of natural products and synthetic pharmaceuticals. Stereoselective methods to produce tetrahydro-β-carboline enantiomers are greatly valued. We report that strictosidine synthase from Ophiorrhiza pumila utilizes a range of simple achiral aldehydes and substituted tryptamines to form highly enantioenriched (ee >98%) tetrahydro-β-carbolines via a Pictet-Spengler reaction. This is the first example of aldehyde substrate promiscuity in the strictosidine synthase family of enzymes and represents a first step toward developing a general biocatalytic strategy to access chiral tetrahydro-β-carbolines. 相似文献
4.
Eudesmanederivativeshavebeendrawingconsiderableattentionduetotheirwidespectrumofbiologicalproperties,particularlyantifeedant,cellgroWthinhibitoryandplantgroWthregulatingactivitiesl'2.Recently,twoepimericeudesmanederivatives( )-5a-hydroxy-6-selinene1and(-)-56-hydroxy-6-selinene2wereisolated3fromtheaerialpartsofCSubtraPicaFMell.,andtheirstructuresweredeterminedbyspectroscopicmethods.Herein,wereportafacilesynthesisofbothtwodiastereomers1and2from( )-dihydrocarvone3infivesteps,usingtheregioselect… 相似文献
5.
Microwave-assisted conjugate addition of indole on nitro-olefins furnished nitro compounds, which were reduced to tryptamines. Further, by using Pictet-Spengler condensation, new 1,4-disubstituted-1,2,3,4-tetrahydro-β-carbolines were synthesized in diastereoselective manner. Dehydrogenation of the tetrahydro-β-carbolines produced new 1,4-disubstituted-β-carbolines. As a new observation, in some of the cases, Pictet-Spengler condensation and dehydrogenation gave two products, namely 1,4-disubstituted-β-carbolines and 1,4-disubstituted-γ-carbolines. A mechanism is proposed for this observation. 相似文献
6.
Ziquan Zhao Yan Sun Lilin Wang Xuan Chen Yanpei Sun Long Lin Yulin Tang Fei Li Dongyin Chen 《Tetrahedron letters》2019,60(11):800-804
Organic base DBN has been identified as an efficient reagent for promoting the dehydrogenative/decarboxylative aromatization of tetrahydro-β-carbolines under air atmosphere, to access the corresponding β-carbolines in moderate to good yields. The utility of this protocol for the gram-scale synthesis of β-carboline alkaloids eudistomin U (7) and harmane (10) has also been demonstrated. 相似文献
7.
The alkylation of indoles by aziridinium ions generated in situ from β-amino chlorides was explored. The outcome of this reaction strongly relied on the substitution pattern of the starting β-amino chloride and requires silver tetrafluoroborate activation to proceed in reasonable yield. Ephedrine- and pseudoephedrine-derived N-cyanomethyl-β-amino chlorides afforded the corresponding tryptamines in a regio- and stereoselective manner and subsequent silver(I)-promoted Pictet–Spengler reactions produced 4-phenyl substituted THBCs in good yields. Unexpected epimerization at C-3 was found in these reactions, producing trans-3,4-disubstituted THBCs stereoselectively. 相似文献
8.
The tetrahydro-β-carboline (THBC) nucleus is a predominant feature of a vast array of naturally occurring alkaloids. Most of these alkaloids have been found to exhibit significant biological activities, which promote to develop a plethora of synthetic methods for the construction of THBCs. In this review, we focus on the recent developments and studies related to the synthesis of THBCs including total syntheses of related alkaloids mainly over the period of 2000–2017. In addition, a brief account of some significant THBC alkaloids with their sources and bioactivities is also presented in tabular format. 相似文献
9.
Mehdi Ghandi Mahdieh Mahami Ahangaran Alireza Abbasi 《Journal of the Iranian Chemical Society》2017,14(5):1131-1137
A one-pot five-component two-step sequential synthesis of tetrazole-based tetrahydrospiro[indene-2,1′-pyrido[3,4-b]indole]-1,3-diones in moderate to good yields is described. The reaction consists of four-component condensation of aromatic aldehydes with tryptamine, trimethylsilyl azide (TMSN3) and isocyanides, followed by addition of ninhydrin. These reactions presumably proceeded through Ugi-azide/Pictet–Spengler processes, respectively. 相似文献
10.
Functionalized spiro-tetrahydro-β-carbolines were formed by an efficient gold(I)-catalyzed rearrangement reaction of alkynylaziridine indoles. The reaction involved a Friedel–Crafts type intramolecular reaction of alkynylaziridine indoles, following by hydroamination of aminoallene intermediate. 相似文献
11.
Arun K. Sarkar Sushama M. Pawar Khushi L. Matta 《Journal of carbohydrate chemistry》2013,32(2):269-278
ABSTRACT Synthesis of three tetrasaccharides, namely, 0-α-L-fucopyranosyl-(1→3)-0-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→3)-0-(β-D-galactopyranosyl)-(1→4)-β-D-glucopyranose (7), 0-α-L-fucopyranosyl-(1→4)-0-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→3)-0-(β-D-galactopyranosyl)-(1→4)-D-glucopyranose (9), and 0-α-L-fucopyransoyl-(1→3)-0-(2-acetamido-2-deoxy-β-D-glucopyransoyl)-(1→6)-0-(β-D-galactopyranosyl)-(1→4)-D-glucopyranose (15) has been described. Their structures have been established by 13C NMR spectroscopy. 相似文献
12.
对α-氨基-β-酮酸酯(β-含氧二肽)的合成进行了探讨.以Boc保护的(L)-缬氨酸及(L)-异亮氨酸为原料,分别与(D,L)-苏氨酸甲酯盐酸盐进行偶合,再用Dess-Martin试剂(DMP)氧化,分别以48%和38%的总收率得到相应的氨基酮酸酯二肽化合物. 相似文献
13.
《Tetrahedron: Asymmetry》2000,11(23):4681-4686
A short and efficient synthesis of the title compounds is described. (S)-(−)-β-Cuparenone was prepared in 31% yield from p-tolualdehyde and mesityl oxide in eight steps. Absolute stereochemistry was established by means of a diastereoselective cyclopropanation using (R,R)-hydrobenzoin as a recoverable auxiliary. 相似文献
14.
Yan-Ni Sun Cui-Ling Wang Ning Zhang Zheng Wang Zhu-Lan Liu Jian-Li Liu 《中国化学快报》2014,25(11):1503-1506
Tetrahydro-b-carbolines with strictosamide skeleton have been synthesized via intermolecular condensation, selective reduction, and intramolecular cyclization starting from phthalic anhydrides and tryptamine. The reactions are carried out under mild conditions with a wide range of substrates and functional groups. 相似文献
15.
Ring opening of indole functionalised methyleneaziridines (3a-c, 7) with alcohols in the presence of boron trifluoride etherate leads to the formation of 1,1-disubstituted tetrahydro-β-carbolines in moderate to good yields (37-83%). 相似文献
16.
17.
Abstract (R)-(?)-β-Cuparenone has been synthesized from (S)-(+)-acid-2 obtained via resolution of the racemic acid. Two of the noteworthy steps are (a) repeated methylation of ester (+)-8 with LDA/MeI to furnish (+)-10 and (b) the reaction of 12, having two neopentyl units with NaCN. 相似文献
18.
Zemmouri R Kajjout M Castanet Y Eddarir S Rolando C 《The Journal of organic chemistry》2011,76(19):7691-7698
We report here the stereoconvergent formylation of (E/Z)-β-bromo-β-fluorostyrene mixtures with carbon monoxide and sodium formate catalyzed by palladium. Optimization of reaction conditions leads to the corresponding pure (Z)-α-fluorocinnamaldehydes in good yields. The reaction was extended to styrenes bearing electro-attracting or electro-donating groups. The obtained α-fluoroaldehydes were smoothly reduced to the corresponding (Z)-β-fluorocinnamic alcohol by NaBH(4). The reaction could be performed on functionalized substrates as demonstrated by the access to the glucoside of β-fluoroconiferyl alcohol, (Z)-β-fluoroconiferin, a strong inhibitor of lignin polymerization. 相似文献
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20.
聚(β-羟基丁酸酯)和β-羟基丁酸酯-β-羟基戊酸酯共聚物共混改性研究进展 总被引:4,自引:0,他引:4
综述了近年来聚(β-羟基丁酸酯)和β-羟基丁酸酯-β-羟基戊酸酯共聚物经共混改性所得到的共混物的相容性、结晶性、热性能、加工性能、力学性能和生物降解性能。 相似文献