首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 234 毫秒
1.
棉红铃虫性信息素已在我国广泛地应用于该虫的测报.该性信息素的合成已有报道。为了使原有的合成路线更适宜于大量生产,本文报道如下的改进合成路线。  相似文献   

2.
双异丙烯基二茂金属(Sn,Ti)的合成   总被引:1,自引:0,他引:1  
虽然,廿多年来各同学者对二茂铁衍生物进行了深入的研究,但却极少报道合成二茂锡衍生物,仅见1959年Wilkinson等合成双甲熬二茂锡以及Cowley等合成(Me3SiC5H4)2Sn和[(i-Pr2N)2PC5H4]2sn,二茂钛衍生物的报道较多,但除Rausch等报道过合成低产率的乙烯基二氯二茂钛(Ⅳ)外,几乎没有报道过类似的烯烃二茂钛(Ⅳ)的合成。  相似文献   

3.
含钛分子筛的水热合成工作已有报道,有关催化性能的研究尚未见报,本文报道了十五烷裂解反应中Ti-ZSM-5分子筛的催化行为,所用Ti-ZSM-5分子筛的合成与表征见文献[2]。  相似文献   

4.
苯甲酰甲酸酯是重要的有机合成中间体,常用作不对称合成试剂.。文献[1-6]报道了合成苯甲酰甲酸酯的几种方法。这些方法各存在一些缺点,如试剂昂贵,反应步骤多,操作困难,收率低等。文献[5,6]报道了氧化相应的扁桃酸酯合成苯甲酰甲酸甲酯和乙酯的方法,反应简单,收率良好,但没有报道其它酯的合成方法。  相似文献   

5.
噻吩并嘧啶酮衍生物是一类具有良好生物活性的稠杂环化合物.文献中已报道了多种这类杂环的合成方法,然而2-氨基取代的噻吩并嘧啶酮衍生物却缺乏有效的制备方法.最近,氮杂Wittig反应广泛地应用于氮杂环的合成,该反应原料易得、条件温和、反应选择性好,已成为一种合成氮杂环的有效手段.我们曾报道应用氮杂Wittig反应合成咪唑啉酮和喹唑啉酮杂环的新方法,这里进一步报道应用该法合成噻吩并嘧啶酮杂环.  相似文献   

6.
王先元  张健 《应用化学》1989,6(6):58-60
某些人工合成的金属卟啉,由于其活化分子氧的功能,被广泛用作生物模拟氧化反应中的催化剂。金属四苯基卟啉及其衍生物是用得最普遍的模型化合物。文献中巳报道过各种四苯基卟啉衍生物的合成方法,但尚未见带烷硫基的四苯基卟啉衍生物的系统合成方法。本文报道这类四苯基卟啉衍生物及其金属配合物的合成。 本文采用通常的一步法合成四苯基卟啉衍生物,即首先参照文献方法合成烷硫基苯甲  相似文献   

7.
合成5-氯2-氨基苯膦酸的新方法   总被引:1,自引:0,他引:1  
报道了以2.5-二氯苯胺为原料合成5-氯-2氨基苯膦酸的新方法,总产率达41%,是文献报道的以间氯苯胺为原料的合成方法的总产率的近3倍。  相似文献   

8.
三年前,本刊曾报道107号元素合成的尝试。1981年4月西德G.Münzenberg等向Z.Physik投稿的最近实验报道,表明他们实现了这一元素的合成。  相似文献   

9.
利用天然手性源来合成一些复杂的手性化合物,其合成策略往往具有很高的艺术性.本文主要对糖类和甘露糖以及一些氨基酸类天然产物作为合成子来合成手性分子的一些新方法作了报道.  相似文献   

10.
2-羟基雌甾化合物是人体内对生理机能有重要意义的雌激素代谢产物,其在生物体内的含量极少,需用化学方法合成来满足研究、应用的需要。迄今为止,已报道了较多合成2-羟基和4-羟基雌甾化合物的方法[1-3],但选择性和产率并不十分理想。我们在文献报道的合成路线[1]的基础上,合成了  相似文献   

11.
Three new glycosides, (3β,5α,8α,11α,12β,14β,17α,20R)‐3‐[(2,6‐dideoxy‐4‐O‐(6‐deoxy‐3‐O‐methyl‐β‐D ‐allopyranosyl)‐3‐O‐methyl‐β‐D ‐arabino‐hexopyranosyl)oxy]‐12‐O‐tigloyl‐8,20 : 11,20‐diepoxypregnane‐12,14‐diol ( 1 ), (3β,5α,8α,11α,12β,14β,17α,20R)‐3‐[(2,6‐dideoxy‐4‐O‐(6‐deoxy‐3‐O‐methyl‐β‐D ‐ allopyranosyl)‐3‐O‐methyl‐β‐D ‐arabino‐hexopyranosyl)oxy]‐12‐O‐(2‐methylbutanoyl)‐8,20 : 11,20‐diepoxypregnane‐12,14‐diol ( 2 ), and (3β,5α,11α,12β,14β,17α)‐12‐acetoxy‐3‐[(2,6‐dideoxy‐4‐O‐(6‐deoxy‐3‐O‐methyl‐β‐D ‐allopyranosyl)‐3‐O‐methyl‐β‐D ‐arabino‐hexopyranosyl)oxy]‐20‐oxo‐8,14‐epoxypregnan‐ 11‐yl isobutyrate ( 3 ) were isolated from the stems of Marsdenia tenacissima. The structures of the new compounds were elucidated by means of spectral data, including HR‐ESI‐MS, and 1D‐ and 2D‐NMR.  相似文献   

12.
Six new triterpenoid glycosides, gynosaponins I–VI ( 1 – 6 , resp.), together with three known compounds, ginseng Rb1 ( 7 ), gypenoside XLIX ( 8 ), and gylongiposide I ( 9 ), were isolated from the aerial parts of Gynostemma pentaphyllum. Based on ESI‐MS, IR, 1D‐ and 2D‐NMR data (HMQC, HMBC, COSY, and TOCSY), the structures of the new compounds were determined as (3β,12β,20S)‐trihydroxydammar‐24‐ene 20‐O‐[α‐rhamnopyranosyl‐(1→2)]‐β‐glucopyranoside ( 1 ), (3β,12β,20S)‐trihydroxydammar‐24‐ene 20‐O‐[α‐rhamnopyranosyl‐(1→2)] [α‐rhamnopyranosyl‐(1→3)]‐β‐glucopyranoside ( 2 ), (3β,12β,20S)‐trihydroxydammar‐24‐ene 3‐Oβ‐glucopyranosyl‐20‐O‐[α‐rhamnopyranosyl‐(1→2)]‐β‐glucopyranoside ( 3 ), (3β,12β,20S)‐trihydroxydammar‐24‐ene 3‐Oβ‐glucopyranosyl‐20‐O‐[α‐rhamnopyranosyl‐(1→2)] [α‐rhamnopyranosyl‐(1→3)]‐β‐glucopyranoside ( 4 ), (3β,12β,20S)‐trihydroxydammar‐24‐ene 3‐O‐{[β‐glucopyranosyl‐(1→2)]‐β‐glucopyranosyl}‐20‐O‐[α‐rhamnopyranosyl‐(1→2)]‐β‐glucopyranoside ( 5 ), and (3β,12β,20S)‐trihydroxydammar‐24‐ene 3‐O‐{[β‐glucopyranosyl‐(1→2)]‐β‐glucopyranosyl}‐20‐O‐[α‐rhamnopyranosyl‐(1→2)] [α‐rhamnopyranosyl‐(1→3)]‐β‐glucopyranoside ( 6 ).  相似文献   

13.
A new cardenolide and two new pregnane glycosides, periplogenin 3‐[Oβ‐glucopyranosyl‐(1→4)‐β‐sarmentopyranoside] ( 1 ), (3β,20S)‐pregn‐5‐ene‐3,17,20‐triol 20‐[Oβ‐glucopyranosyl‐(1→6)‐O‐glucopyranosyl‐(1→4)‐β‐canaropyranoside] ( 2 ), and (3β,14β,17α)‐3,14,17‐trihydroxy‐21‐methoxypregn‐5‐en‐20‐one 3‐[Oβ‐oleandropyranosyl‐(1→4)‐Oβ‐cymaropyranosyl‐(1→4)‐β‐cymaropyranoside] ( 3 ), were isolated from the root barks of Periploca sepium Bge , together with seven related known compounds, periplogenin, xysmalogenin, (3β,20S)‐pregn‐5‐ene‐3,17,20‐triol, (3β,14β,17α)‐3,14,17‐trihydroxy‐21‐methoxypregn‐5‐en‐20‐one, (3β,20S)‐pregn‐5‐ene‐3,20‐diol 3‐β‐glucopyranoside 20‐β‐glucopyranoside, (3β,20S)‐pregn‐5‐ene‐3,20‐diol 3‐[O‐2‐O‐acetyl‐β‐digitalopyranosyl‐(1→4)‐β‐cymaropyranoside] 20‐[Oβ‐glucopyranosyl‐(1→6)‐Oβ‐glucopyranosyl‐(1→2)‐β‐digitalopyranoside], and (3β,20S)‐ pregn‐5‐ene‐3,20‐diol 20‐[Oβ‐glucopyranosyl‐(1→6)‐β‐glucopyranoside]. Their structures were elucidated on the basis of spectroscopic analyses.  相似文献   

14.
Eight new acylated preatroxigenin saponins 1 – 8 were isolated as four inseparable mixtures of the trans‐ and cis‐4‐methoxycinnamoyl derivatives, atroximasaponins A1/A2 ( 1 / 2 ), B1/B2 ( 3 / 4 ), C1/C2 ( 5 / 6 ) and D1/D2 ( 7 / 8 ) from the roots of Atroxima congolana. These compounds are the first examples of triterpene saponins containing preatroxigenin (=(2β,3β,4α,22β)‐2,3,22,27‐tetrahydroxyolean‐12‐ene‐23,28‐dioic acid as aglycone. Their structures were elucidated on the basis of extensive 1D‐ and 2D‐NMR studies and FAB‐MS as 3‐O(β‐D ‐glucopyranosyl)preatroxigenin 28‐{Oβ‐D ‐xylopyranosyl‐(1→4)‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐O‐[Oβ‐D ‐glucopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→3)]‐4‐O‐(trans‐4‐methoxycinnamoyl)‐β‐D ‐fucopyranoyl} ester ( 1 ) and its cis‐isomer 2 , 3‐O‐(β‐D ‐glucopyranosyl)preatroxigenin 28‐{Oβ‐D ‐xylopyranosyl‐(1→4)‐Oα‐L ‐rhamnopyranosyl‐(1→ 2)‐O‐[O‐6‐O‐acetyl‐β‐D ‐glucopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→3)]‐4‐O‐(trans‐ 4‐methoxycinnamoyl)‐β‐D ‐fucopyranosyl} ester ( 3 ) and its cis‐isomer 4 , 3‐O‐(β‐D ‐glucopyranosyl)preatroxigenin 28‐{Oβ‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐O‐[O‐6‐ O‐acetyl‐β‐D ‐glucopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→3)]‐4‐O‐(trans‐4‐methoxycinnamoyl)‐β‐D ‐fucopyranoyl} ester ( 5 ) and its cis‐isomer 6 , 3‐O‐(β‐D ‐glucopyranosyl)preatroxigenin 28‐{Oβ‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐O‐[Oβ‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→3)]‐4‐O‐(trans‐4‐methoxycinnamoyl)‐β‐D ‐fucopyranosyl ester ( 7 ) and its cis‐isomer 8 .  相似文献   

15.
Four new furostanol steroid saponins, borivilianosides A–D ( 1 – 4 , resp.), corresponding to (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐hydroxyfurostan‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→3)‐Oβ‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside ( 1 ), (3β,5α,22R,25R)‐ 26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→3)‐Oβ‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside ( 2 ), (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→2)]‐Oβ‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 3 ), and (3β,5α,25R)‐26‐(β‐D ‐glucopyranosyloxy)furost‐20(22)‐en‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→2)]‐Oβ‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 4 ), together with the known tribuluside A and (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl Oβ‐D ‐xylopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐Oβ‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside were isolated from the dried roots of Chlorophytum borivilianum Sant and Fern . Their structures were elucidated by 2D ‐NMR analyses (COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry.  相似文献   

16.
The hydrolysis reactions of N-(O,O'diisopropyl)phosphoryl-L-α-alanine (DIPP-L-α-Ala), N-(O,O'diisopropyl)- phosphoryl-D-α-alanine (DIPP-D-α-Ala), N-(O,O'-diisopropyl)phosphoryl-β-alanine (DIPP-β-Ala) and N-(O,O'-diisopropyl)phosphoryl-γ-amino butyric acid (DIPP-γ-Aba), were studied by HPLC and their hydrolysis reaction kinetic equations were obtained. Under acid conditions, the reaction rate of DIPP-L-α-Ala was close to that of DIPP-D-α-Ala and the same rule was true between DIPP-β-Ala and DIPP-γ-Aba. Meantime, the reaction rate of DIPP-L/D-α-Ala was as 10 times as that of DIPP-β-Ala or DIPP-γ-Aba. Under basic conditions, the hydrolysis reactions of DIPP-β-Ala and DIPP-γ-Aba almost did not take place and the reaction rate of DIPP-L/D-α-Ala was about 1/10 of that under acid conditions. Moreover, theoretical calculation further illuminated the differences of the hydrolysis rate from the view of energy. The results would provide some helpful clues to why nature chose a-amino acids but not other kinds of analogs as protein backbones.  相似文献   

17.
The five new presenegenin glycosides 1 – 5 were isolated from Securidaca welwitschii, together with one known sucrose diester. Compounds 1 – 4 were obtained as pairs of inseparable (E)/(Z)‐isomers of a 3,4‐dimethoxycinnamoyl derivative, i.e., 1 / 2 and 3 / 4 . Their structures were elucidated mainly by 2D‐NMR techniques and mass spectrometry as 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐{Oβ‐D ‐xylopyranosyl‐(1→4)‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐glucopyranosyl‐(1→3)]‐4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]‐β‐D ‐fucopyranosyl} ester ( 1 ) and its (Z)‐isomer 2 , 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28{Oβ‐D ‐galactopyranosyl‐(1→4)‐Oβ‐D ‐xylopyranosyl‐(1→4)‐O‐3‐O‐acetyl‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐glucopyranosyl‐(1→3)]‐4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]‐β‐D ‐fucopyranosyl} ester ( 3 ) and its (Z)‐isomer 4 , and 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐[Oβ‐D ‐galactopyranosyl‐(1→3)‐Oβ‐D ‐xylopyranosyl‐(1→4)‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐fucopyranosyl] ester ( 5 ) (presenegenin=(2β,3β,4α)‐2,3,27‐trihydroxyolean‐12‐ene‐23,28‐dioic acid).  相似文献   

18.
Five new triterpene saponins 1 – 5 were isolated from the roots of Muraltia ononidifolia E. Mey along with the two known saponins 3‐O‐[Oβ‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐[Oβ‐D ‐xylopyranosyl‐(1→4)‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester and 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐[Oα‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester (medicagenic acid=(4α,2β,3β)‐2,3‐dihydroxyolean‐12‐ene‐23,28‐dioic acid). Their structures were elucidated mainly by spectroscopic experiments, including 2D‐NMR techniques, as 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐[Oβ‐ D ‐apiofuranosyl‐(1→3)‐Oβ‐D ‐xylopyranosyl‐(1→4)‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester ( 1 ), 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐{[Oβ‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl} ester ( 2 ), 3‐O‐[Oβ‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐{Oβ‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐Oα‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl} ester ( 3 ), 3‐O‐[Oβ‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐[Oα‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester ( 4 ), and 3‐O‐[Oβ‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid ( 5 ).  相似文献   

19.
Four new tirucallane triterpenoid saponins, named munronosides I–IV ( 2 – 5 ), along with three known triterpenoids, sapelin B ( 1 ), melianodiol, and (3β)‐22,23‐epoxytirucall‐7‐ene‐3,24,25‐triol, were isolated from the EtOH extract of the whole plants of Munronia delavayi Franch by chromatographic methods. On the basis of spectroscopic evidences, the structures of 2 – 5 were elucidated as (20S,23R,24S)‐21,25‐epoxy‐29‐{{Oβ‐d‐ glucopyranosyl‐(1→3)‐O‐[α‐l‐ rhamnopyranosyl‐(1→6)]‐β‐d‐ glucopyranosyl}oxy}‐23,24‐dihydroxytirucall‐7‐ene‐3,21‐dione ( 2 ), (3β,20S,23R,24S)‐21,25‐epoxy‐29‐{{Oβ‐d‐ glucopyranosyl‐(1→3)‐O‐[α‐l‐ rhamnopyranosyl‐(1→6)]‐β‐d‐ glucopyranosyl}oxy}‐3,23,24‐trihydroxytirucall‐7‐en‐21‐one ( 3 ), (20S,23R,24S)‐24‐(acetyloxy)‐21,25‐epoxy‐29‐{{Oβ‐d‐ glucopyranosyl‐(1→3)‐O‐[α‐l‐ rhamnopyranosyl‐(1→6)]‐β‐d‐ glucopyranosyl}oxy}‐23‐hydroxytirucall‐7‐ene‐3,21‐dione ( 4 ), and (3β,20S,23R,24S)‐24‐(acetyloxy)‐21,25‐epoxy‐29‐{{Oβ‐d‐ glucopyranosyl‐(1→3)‐O‐[α‐l‐ rhamnopyranosyl‐(1→6)]‐β‐d‐ glucopyranosyl}oxy}‐3,23‐dihydroxytirucall‐7‐en‐21‐one ( 5 ).  相似文献   

20.
Wittig olefination of (2S,3R,5S,6R)‐5‐(acetyloxy)‐tetrahydro‐6‐[(methoxymethoxy)methyl]‐3‐(phenylthio)‐ 2H‐pyran‐2‐acetaldehyde ((+)‐ 10 ) with {2‐[(2S,3R,4R,5R,6S)‐tetrahydro‐3,4,5‐tris(methoxymethoxy)‐6‐methyl‐ 2H‐pyran‐2‐yl]ethyl}triphenylphosphonium iodide ((?)‐ 11 ) gave a (Z)‐alkene derivative (+)‐ 12 that was converted into (αR,2R,3S,4R,5R,6S)‐tetrahydro‐α,3‐dihydroxy‐2‐(hydroxymethyl)‐5‐(phenylthio)‐6‐{(2Z)‐4‐[(2S,3S,4R,5S,6S)‐tetrahydro‐3,4,5‐trihydroxy‐6‐methyl‐2H‐pyran‐2‐yl]but‐2‐enyl}2H‐pyran‐4‐acetic acid ( 8 ), (αR,2R,3S,4R,6S)‐tetrahydro‐α,3‐dihydroxy‐2‐(hydroxymethyl)‐6‐{4‐[(2S,3S,4R,5S,6S)‐tetrahydro‐3,4,5‐trihydroxy‐6‐methyl‐2H‐pyran‐2‐yl]butyl}‐2H‐pyran‐4‐acetic acid ( 9 ), and simpler analogues without the hydroxyacetic side chain such as (2S,3S,4R,5S,6S)‐tetrahydro‐6‐methyl‐2‐{(2Z)‐4‐[(2S,3R,5S,6R)‐tetrahydro‐5‐hydroxy‐6‐(hydroxymethyl)‐3‐(phenylthio)‐2H‐pyran‐2‐yl]but‐2‐enyl}‐2H‐pyran‐3,4,5‐triol ( 30 ), (2S,3S,4R,5S,6S)‐tetrahydro‐6‐methyl‐2‐{[(2S,5S,6R)‐tetrahydro‐5‐hydroxy‐6‐(hydroxymethyl)‐2H‐pyran‐2‐yl]butyl}‐2H‐pyran‐3,4,5‐ triol ((?)‐ 41 ) and (2S,3S,4R,5S,6S)‐tetrahydro‐6‐methyl‐2‐{(2Z/E))‐4‐[(2R,5S,6R)‐tetrahydro‐5‐hydroxy‐6‐(hydroxymethyl)‐2H‐pyran‐2‐yl]but‐2‐enyl}‐2H‐pyran‐3,4,5‐triol ( 43 ). The key intermediates (+)‐ 10 and (?)‐ 11 were derived from isolevoglucosenone and from L ‐fucose, respectively. The following IC50 values were measured in a ELISA test for the affinities of sialyl Lewis x tetrasaccharide, 8, 9, 30 , (?)‐ 41 , and 43 toward P‐selectin: 0.7, 2.5–2.8, 7.3–8.0, 5.3–5.9, 5.0–5.2, and 3.4–4.1 mM , respectively.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号