- Preparation method of nitrogen-substituted aspartic acid
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The invention discloses a preparation method of nitrogen-substituted aspartic acid, the method comprises the following steps: providing a nitrogen-substituted aspartic acid compound with the structural formula as shown in the specification, wherein R1 is alkyl, and R2 is an amino protecting group; performing deprotection treatment on the nitrogen-substituted aspartic acid compound to obtain the nitrogen-substituted aspartic acid with the structural formula as shown in the specification, and the preparation method disclosed by the invention can be used for reducing the cost of preparing the nitrogen-substituted aspartic acid and enabling the nitrogen-substituted aspartic acid to be suitable for industrial production.
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Paragraph 0054; 0055; 0056; 0057; 0058; 0059; 0060-0062
(2019/01/24)
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- Pig growth urges the medicinal preparation preparation method of gene expression (by machine translation)
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The invention discloses a Pig growth gene expression urges the medicinal preparation preparation method, the present invention relates to a synthesis of amino acid derivatives, in particular to a Pig growth gene expression urges the medicinal preparation D - aspartic acid derivatives, N - methyl - D - aspartic acid of preparation method, through D - aspartic acid as the raw material, the D - aspartic acid with methanol and thionyl chloride reaction generating D - aspartic acid dimethyl ester hydrochloride, then with 40% formaldehyde of the woven fabric under the alkaline condition generating N - hydroxymethyl - D - aspartic acid, using pd/c as the catalyst under normal temperature and pressure hydrogenation to obtain N - methyl - D - aspartic acid; simple preparation method of the invention, the prepared product quality is stable, and in the preparation of environmental pollution, can promote the growth of livestock and at the same time, improve the utilization rate of the feed and the improvement of the quality of the carcass raising the Pig, popularization and application. (by machine translation)
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- Grassypeptolides A-C, cytotoxic bis-thiazoline containing marine cyclodepsipeptides
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Grassypeptolides A-C (1-3), a group of closely related bis-thiazoline containing cyclic depsipeptides, have been isolated from extracts of the marine cyanobacterium Lyngbya confervoides. Although structural differences between the analogues are minimal, comparison of the in vitro cytotoxicity of the series revealed a structure-activity relationship. When the ethyl substituent of 1 is changed to a methyl substituent in 2, activity is only slightly reduced (3-4-fold), whereas inversion of the Phe unit flanking the bis-thiazoline moiety results in 16-23-fold greater potency. We show that both 1 and 3 cause G1 phase cell cycle arrest at lower concentrations, followed at higher concentrations by G2/M phase arrest, and that these compounds bind Cu2+ and Zn 2+. The three-dimensional structure of 2 was determined by MS, NMR, and X-ray crystallography, and the structure of 3 was established by MS, NMR, and chemical degradation. The structure of 3 was explored by in silico molecular modeling, revealing subtle differences in overall conformation between 1 and 3. Attempts to interconvert 1 and 3 with base were unsuccessful, but enzymatic conversion may be possible and could be a novel form of activation for chemical defense.
- Kwan, Jason C.,Ratnayake, Ranjala,Abboud, Khalil A.,Paul, Valerie J.,Luesch, Hendrik
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experimental part
p. 8012 - 8023
(2011/03/20)
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