r**a
发帖数: 121 | 1 看了这个文章，这样一来，似乎leucine就没有特殊了
而且，aa ester也有同样的作用了
而且，tor是不是变成了lysosome 的aa sensor了
或者说，只要改变了vATPase的结构，就影响了tor了
继续看他们倒底在做什么啦，呵呵 |
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s******y
发帖数: 28562 | 3 MCE (mixed cellulose ester) 是给含蛋白的溶液用的
NYLON, PTFE, PVDF 都不能用在含蛋白的溶液上，具体要用哪一种要看你
是不是要过滤有机溶剂,如过只是一般的水溶液而且不含蛋白，那么随便哪个都行。 |
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z*h
发帖数: 773 | 4 Electrofuel does not work. Joule limited is a joke. It may be worse than
Keasling's process.
Fatty acid esters may work due to unique market that ethanol and hydrogen
cannot work. But it may not compete with more efficiency ways in long terms.
Efficiency,cost and competing technologies. |
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A******y
发帖数: 2041 | 5 What's your reaction condition? You need to first make the activated NHS
ester PEG Phospholipid (or buy it if you can) in organic solvent. After
that you can do it in PBS buffer etc. If you run the EDC/NHS activation in
water solution, it won't work. |
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A******y
发帖数: 2041 | 6 Are you sure the one you buy is not already activated? EDC activation
require anhydrous condition (just go search online). Once Osu-ester is form
, it can react with amine in aqueous condition. If you think it is the
micelle, then you have to re-think you sequence of reaction.
COOH. |
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c****u
发帖数: 584 | 7 NHS ester label BSA 效率应该很高啊。你都有30％了. 会不会是biocore灵敏度低.
或非特异高？
positive |
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B******1
发帖数: 9094 | 8 I heard that Dr. Dale Boger once said: to be a true chemist, you have to
distill diazomethane a dozen times . . .
As to Trimethylsilyl Diazomethane, which is a methylating reagent, what kind
of harm can it do in a human body other than making a few methyl esters of
free acids? That beats me.
I know diazomethane is harmless since legend has it that a crazy chemist
sprayed a few mL of a solution of CH2N2 in ether on his arms and he was Okay afterwards. |
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O*R
发帖数: 609 | 9 Title: Synthesis of some phosphate mono-esters.
Author: Agarwal, Anupam. Anni Laboratories, Agra, India.
Journal: Oriental Journal of Chemistry
Year published: 2007
Volume (issue): 23(2)
Pages: 773-774.
发到g*******[email protected]吧，发2个包子答谢！ |
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b*******n
发帖数: 12321 | 10 Is it possible to get 1 isomer of the mono-NHS-folate? It doesn't matter
alpha or gamma NHS ester, but don't
want a mixture of the two.
Thank you in advance! |
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b*****r
发帖数: 203 | 11 It is a sodiated peak. The one at 151.09649 is the actual protonated peak.
The molecular formula for the 173 peak is C6H13O4Na1, mass accuracy: -4.6
ppm. There is no double bond in it. My guess is it is a compound with two
ester bonds. |
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b*****r
发帖数: 203 | 12 I think so. In many cases for this type of neutral species, it should be easy to adduct Na
+. I know esters can easily adduct a Na+. Usually sodiated peaks are more stable at high energy. You may be able to test it by decreasing the tube lens voltage. With decreased tube lens
voltage, the intensity of protonated peak may increase. You might want to look up literature to see if there are any reports on alcohols with Na+ adduct.
On the other hand, the chance for you to see the acid you proposed is |
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p****e
发帖数: 38 | 13 我做poly(N-Hydroxysuccinimide methacrylate),用带amine group的荧光染料去染，
试了很多次都没染上去，到底是怎么回事啊
从NMR或TLC来看， N-Hydroxysuccinimide methacrylate单体和脂肪胺是很容易反应的 |
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m****e
发帖数: 255 | 14 你用的荧光染料上胺基是脂肪胺么？是不是位阻太大？ |
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w******n
发帖数: 13202 | 15 有机溶剂中，我一般用三乙胺或DIEA.
水溶液的话，调pH到8.3。基本没有问题。属于百试百灵的那种反应。
对你的聚合物，就不知道如何了。 |
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T***T
发帖数: 85 | 18 UV弱 你就应该用STAIN阿 看不清楚你怎么过柱提纯呢
我也同感应该不拖尾这个 |
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q****e
发帖数: 3660 | 20 Hi, I am looking for the following paper, thank you in advance for your time.
Syntheses and applications of sucrose-based esters
Journal Journal of Surfactants and Detergents
Publisher Springer Berlin / Heidelberg
ISSN 1097-3958 (Print) 1558-9293 (Online)
Issue Volume 4, Number 4 / October, 2001
Please send it to l****************[email protected]
Thank you! |
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l*****l
发帖数: 25 | 21 请问哪位同仁实验室装有Cambrdige Structural Database, 能否帮忙查
抗坏血酸棕榈酸酯 C22H38O7 (Ascorbyl palmitate / Ascorbyl fatty
acid ester / 6-O-palmitoylascorbic acid / 2-4,5-Dihydroxy-3
-oxo-2-furyl-2-hydroxyethyl hexadecanoate / L-Ascorbic acid 6-hexadecanoate)
只需要晶体空间群,晶胞参数,不胜感激! |
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d****i
发帖数: 360 | 22 One more paper please! Thanks a lot! E-mail: x**********[email protected]
Degradable Poly(β-amino ester) nanoparticles for cancer cytoplasmic drug
delivery
Show Abstract Shen, Y., Tang, H., Zhan, Y., Van Kirk, E.A., Murdoch, W.
J. 2009 Nanomedicine: Nanotechnology, Biology, and Medicine 5 (2), pp. 192-
201 |
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s*******h
发帖数: 3731 | 23 try your luck with the famous Nicolaou reaction...
trimethyltin hydroxide?
it is a selective methyl ester hydrolysis reaction published on ACIE...
many peptide guys use it nowadays... |
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x********e
发帖数: 1064 | 25 Zlatoidsky P. (1994). Helvetica Chimica Acta, 77,150.
Preparation of Boc-Amino-Acid or Peptide Aldehydes via Reduction of
Corresponding Phenyl Esters (p 150-154)
Please send to t*********[email protected] |
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w**q
发帖数: 43 | 26 Just a thought.
For ester alone, s-cis form is favored(anomeric, A1,2 and dipole).
After addn of AlCl3, for Me, the s-trans...AlCl3 could be stable since Me is
small. But for Et, both s-cis...AlCl3 and s-trans...AlCl3 are unstable
complex due to steric effect. s-cis...AlCl3 is ready for IM cleavage of Et. |
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x*********i
发帖数: 170 | 27 converting ester to aldehyde under -78, do I need to slowly add the DIBAL?
Please share the experience, thank you very much |
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q****e
发帖数: 3660 | 28 METHOD FOR PRODUCING GLYCEROL MONOFATTY ACID ESTER
PAJ 06-01-10 10120910 JP NDN- 043-0524-5862-7
PATENT APPLICATION NUMBER- 2008298307
DATE FILED- 2008-11-21
PUBLICATION NUMBER- 10120910 JP
DOCUMENT TYPE- A
PUBLICATION DATE- 2010-06-03
INTERNATIONAL PATENT CLASS- C07C06708 ; C11C00304 ; C07C06930; C07B06100
APPLICANT- KAO CORP
PUBLICATION COUNTRY- Japan
Hope this patent is not written in Japanese :)
Thank you for your help! |
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s**********e
发帖数: 2888 | 30 是不是变成fatty acid ester之后会容易纯化一点？
我现在做的两个fatty acid isomers的混合物，结构差异很小，一个是一个primary
alcohol，一个是secondary alcohol，有没有什么化学反应可以区分的？
因为需要大量的分离，所以虽然HPLC可以实现，但是还是想找到尽量简单的方法。
谢谢 |
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s***o
发帖数: 58 | 31 Tetrahedron, 48(22), 4623-8; 1992
Convenient methods for the reduction of amides, nitriles, carboxylic esters,
acids and hydroboration of alkenes using the sodium borohydride-iodine
system |
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q****e
发帖数: 3660 | 32 Study on the kinetics of synthesis of sorbitan oleic acid ester
Yinbao Xie; Xinsheng Xu; Jinzong Yang; Shude Li
Dep. Fine Chem. Eng., Dalian Univ. Technol., Dalian, 116012, Peop. Rep.
China
Journal
Riyong Huaxue Gongye (1995), (6), 1-7
Thank you! |
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p**********m
发帖数: 472 | 33 你说的对，保护集团估计不太行，可能是形成的ENOLATE intramolecular 跟ester 反
应，还是会形成氧anion， 其实跟没保护一样。
对于第一个comment， 估计你没看清楚，连得是一个碳，这个ALPHA 氢我估计更酸把 |
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w******e
发帖数: 1187 | 34 我用的RNA约80base，2'-F modified。直接用chemical synthesis同时加functional
group太贵，只好自己从DNA template trancribe出RNA，同时加amino-GMP在
5’加amino group，再从amino group变成其他functional group using NHS
ester.
我不是化学出身所有上述都是第一回做，提心吊胆，每步的yield也不知道怎么
确定。不知道有没有公司会
提供外包服务，我提供RNA，帮我在两端加上各种group？非常感谢！ |
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s********s
发帖数: 579 | 36 Efficient syntheses of 4-iodopyridine and of 4-pyridylboronic acid pinacol
ester
Synthetic communications [0039-7911] Coudret yr:1996 vol:26 iss:19 pg:3543 |
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s***r
发帖数: 67 | 37 标题: A novel organocatalytic tool for the iminium activation of alpha,beta-
unsaturated ketones
作者: Bartoli, G; Melchiorre, P
来源出版物: SYNLETT 期: 12 页: 1759-1772 出版年: 2008
标题: Bronsted Acid-Thiourea Co-catalysis: Asymmetric Synthesis of Functionalized 1,4-Dihydropyridines from beta-Enamino Esters and alpha,beta-Unsaturated Aldehydes
作者: Yoshida, K; Inokuma, T; Takasu, K, et al.
来源出版物: SYNLETT 期: 12 页: 1865-1869 出版年: 2010
标题: Divergent stereoinduction mechanisms in urea-catalyzed additio... 阅读全帖 |
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b*******t
发帖数: 57 | 38 Title: Functional selectivity in phosphonate ester dealkylation with
bromotrimethylsilane
Authors: Charles E. McKenna and John Schmidhuser
Journal: J. Chem. Soc., Chem. Commun., 1979, 739-739
DOI: 10.1039/C39790000739, Paper
link:http://pubs.rsc.org/en/Content/ArticleLanding/1979/C3/C39790000739
Thanks in advance! |
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d****i
发帖数: 360 | 39 Polymer
Volume 13, Issue 10, October 1972, Pages 462-464
High polymers of acrylic and methacrylic esters of N-hydroxysuccinimide as
polyacrylamide and polymethacrylamide precursors
P. Ferrutia, A. Bettellia and Angelino Feréa
Thanks a lot! |
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d****i
发帖数: 360 | 40 Help me please! Thanks a lots!
Polymer
Volume 13, Issue 10, October 1972, Pages 462-464
High polymers of acrylic and methacrylic esters of N-hydroxysuccinimide as
polyacrylamide and polymethacrylamide precursors
P. Ferrutia, A. Bettellia and Angelino Feréa
Thanks a lot! |
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m******g
发帖数: 39 | 41 版上大牛,救命啊. 我想用FDAA (Marfey reagent) derivitize 我的amino(NH2)-ester
-salt(HCl) 手性对应体(几乎没有UV吸收). 我的compound溶在含过量TEA的DCM中. 这
样TEA先中和掉compound中的HCl,NH3(+)Cl(-)-R-COOCH3 变成NH2-R-COOCH3 然后和4%
的FDAA in ACN 反应. FDAA过量一些. 反应在50C, 进行2小时. 上HPLC column, 结果
居然没看见我的compound的peak. 看起来就像没反应, FDAA到像是falling apart了.
大牛看看我的反应条件是不是有问题啊? |
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d****i
发帖数: 360 | 42 Journal of Materials Science: Materials in Medicine
Volume 22, Number 3, 469-479, DOI: 10.1007/s10856-011-4243-5
Synthesis and characterization of ionic charged water soluble arginine-based
poly(ester amide)
Jun Wu, Martha A. Mutschler and Chih-Chang Chu
Thanks a lot! |
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y*****n
发帖数: 205 | 45 有一个聚合物，酯是叔丁酯，聚合物又含有双键，二者大概1：1比例（ester/double
bond），在不损害双键的情况下怎么把酯水解阿？三氟乙酸，盐酸之类的会将双键饱和
，聚合物不溶于水，能溶于THF之类的有机溶剂！
如果当作小分子处理的话（含双键的酯），在不用水作溶剂，如何水解？
搞不定阿，
多谢多谢 |
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J*J
发帖数: 132 | 46 不好意思， 不知道那个连接不能用，这是其他的Info
Convenient preparations of t-butyl esters and ethers from t-butanol
Tetrahedron Letters, Volume 38, Issue 42, 20 October 1997, Pages 7345-7348
Stephen W. Wright, David L. Hageman, Ann S. Wright, Lester D. McClure
谢谢了 |
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j*****d
发帖数: 60 | 47 Sorry, since the synthesis of the key intermediate 8 will be publish
somewhere else, I had thought there is a easy way to direct change amide
into thioamide.
By the way, is there a good (easy) way to change ester in a complex natural
product to an amide?
抠出 |
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h********g
发帖数: 143 | 48 大家好，小弟在这里也来问一个-COOH与-OH反应的问题，
我花了挺久来重复一篇paper里面的一个反应，见下图
文章的link是
http://pubs.acs.org/doi/abs/10.1021/jo0518809
paper里面的产率高达98%，但是我做出来的却最高也只有50%。
主要的副产物经过分离纯化之后，NMR、IR、MS确认可能是两种结构，见下图两个ester。
可能是我的原料或者产物和作为溶剂的2-ethoxyethanol反应了。
我怀疑过可能是有氢离子催化的esterification。
我纯化过原料和solvent，也加过过量的K2CO3。但是也没有帮助。
各位大牛能不能指点一下，问题可能出在哪里？
我加的Cu/Cu2O在高温下容易从红色（Cu2O的颜色）变绿（有Cu(II)）。
这个也始终不知道为什么...
拜谢！ |
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s*******h
发帖数: 3731 | 49 梦梦小弟你好，
50%的产率也行了，第一步可以放大吗。。另外你的副产品水解以后就是你的产
品了。。。
ester。 |
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h********g
发帖数: 143 | 50 先拜过超工，沾沾仙气~~
因为我想利用这个反应做成polymer，所以反应产率高点儿，得到的polymer的链才长些。
另外，也觉得重复不出来别人的反应，心里很不爽。有点儿钻牛角尖儿，嘿嘿~~
水解这个主意真的很聪明，超工你太赞了。我去试一试。
就是不知道到时候ester会不会影响polymer的合成，或者post-polymerization的水解
效果怎么样。
2-ethoxyethanol的沸点高达135C，没法加热出去。只能是用过量的碱来移动平衡了。 |
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