O**********0
发帖数: 61 | 1 ☆─────────────────────────────────────☆
BHistory (往者的影子) 于 (Fri Sep 9 00:20:11 2011, 美东) 提到:
俺曾认为生命是进化起源的，后来越找越发现进化论像是信仰而非科学结论。可是每有
飞机网友觉着俺如此看待进化论是反科学了。
所以俺本着科学的精神，问个问题，求各位飞机进化论牛人给个科学的答案。
大家知道达尔文进化论是以遗传机制为基础的，第一个有遗传机制的生命怎么来的，当
时根本没有提及。
后人发现这一问题后，就又提出了化学进化论，就是无机分子在某种机制下，自动组合
出了第一个有遗传的生命。此后达尔文进化论似乎可以take care（其实未必，今后再
讨论）。
今天我们先看比第一个有遗传生命的出现简单万亿倍的问题，第一个蛋白质如何化学进化出
现？
先亮亮俺一个愚昧基督徒的愚见：
已知最简单的具有遗传机制的单细胞生命的复杂度已经远远超出人们最初的想象，大概
有400种蛋白质几十万个组成。其中较小的蛋白质大概100个氨基酸，如果在随机热运动
中组成，因为自然界对称的氨基酸不少于40种（20多种氨基酸及... 阅读全帖 |
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s*****l
发帖数: 1844 | 2 Are you kidding me? Discovery research is already outsourced, and is the
easiest part to outsource. Small molecules systhesis and bioactivity test,
early phase animal study, raw material systhesis, etc. are good examples. So
far most of the big pharma's sites in China are doing at least some
research.
Development part is more difficult to outsource because regulation is much
more strict. Development part is to make DS, DP for clinical trials, and the
quality of the product is much more critical ... 阅读全帖 |
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E*********r
发帖数: 4984 | 3 I think I am probably the best person to answer this question as one of my
projects at San Francisco General Hospital is to differentiate cholesterol
imbalance. There are two major routes for cholesterol accumulation in the
body.
The first one is through in vivo biosynthesis via a key enzyme called HMGCoA
reductase. Therefore, in order to lower cholesterol based on de novo
systhesis, a drug family called statins, is widely used because it inhibits
this key enzyme. Nowadays, measuring the conc... 阅读全帖 |
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l**********t
发帖数: 5754 | 4 although the probability is not equal, comparing a complicated organic
systhesis of functional peptide with the simplest inorganic reaction is a
bit self-serving. |
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E*****m
发帖数: 25615 | 5
systhesis --> synthesis |
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c**r
发帖数: 2019 | 6 Well, maybe I have to apologize. You are right, organic,
especially natural-product-systhesis, is fine. However, it's
no better than ChE or Polymer. A Chinese student in
analytical division just downstairs my lab went to P&G last
year. But it was only a sort of randomcy. |
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s*****r
发帖数: 477 | 7 需要合成D-amino acid peptide做in vivo blocking，请有经验的人推荐一下哪些公司
质量比较好？ |
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s*****r
发帖数: 477 | 8 需要合成D-amino acid peptide做in vivo blocking，请有经验的人推荐一下哪些公司
质量比较好？ |
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l**********e
发帖数: 146 | 9 用过Genscript,好用还不贵，但是我的是常规的8aa的多肽，不知道具体你的样品情况
。 |
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f******g
发帖数: 382 | 11 我用过GeneScript做全D的， 还可以。 |
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d********w
发帖数: 1110 | 12 请教一个问题。合成monomer的最后一步上phosphoramidite 的时候，我用的是2-
ethylcyano-n,n-diisopropylchlorophosphoramidite.我用EA:HEXANE=3:1把产品走出
来，可是做31P NMR时发现在大约15ppm的地方有一个很高的峰，过了好几遍柱子也除不
掉。请问有人有类似经验吗？ |
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e******y
发帖数: 106 | 13 你把用的chloro-phosphoramidite做个31P 看看是不是它被氧化了 |
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d********6
发帖数: 76 | 14 柱子走出来的东西用极少量DCM溶解了，慢慢加到hexanes或者pentane里面把产品沉淀出来。
有的时候可以除掉杂质。 |
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c***r
发帖数: 3965 | 15 氧化了。
重新走柱子，要用氮气flash column.
最后样品要充分抽干，全程氮气保护 |
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d********w
发帖数: 1110 | 16 应该不是氧化的产品。因为我的产品有颜色和荧光，我把nmr样品重新走tlc，可以看到
基本上还是我的产品一个很大的点。可是nmr里面15ppm那个峰要比我150ppm的产品的峰
高好大一截。 |
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d********w
发帖数: 1110 | 17 我又把产品用NaHCO3洗了一下，15ppm的杂质峰还在那里。做了一个chloro-
phosphoramidite的原料的谱，觉得是原料被部分氧化了。可问题是这个杂质和我的产
品极性差不多，过柱总是一起出来，又没办法通过uv或者stain看到它，我该怎么纯化
呢？ |
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e******y
发帖数: 106 | 18 这个氧化的杂质应该不影响你下一步反应.如果你只需要纯品做核磁用 用prepTLC纯化
几十毫克就好了. |
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g***e
发帖数: 589 | 21 你这个展开剂极性太大，估计是水解的 phosphoramidite 跟着产物一起下来了吧，我
用过类似的展开剂，产物和原料分不开。你用ninhydrine做显色剂看看。 |
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d********w
发帖数: 1110 | 22 水解的产物是酸，应该能用NaHCO3 aq 洗掉的。我个人感觉是氧化后的P(V) 副产品,
因为它的磷谱和不纯的原料中的一个峰位移是一样的。 |
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s*****l
发帖数: 1844 | 23 Does not the patent belong to the company,even though some scientists' name
may be on the patent since company pays salary, provides all equipment, and
sponsors the project?
BTW, what do you mean by inventing a drug? The person who figured out the
systhesis of a potential blockbuster got laidoff here because of politics.
This guy may not invent the drug, but without him the synthesis/scale up is
impossible or would be delayed a lot. He clearly contributed a lot to the
potential success of the d... 阅读全帖 |
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