伪枝藻素：修订间差异
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| 伪枝藻素 | |
|---|---|
| |
| IUPAC名 (3E,3'E)-3,3'-bis(4-hydroxybenzylidene)-[1,1'-bi(cyclopenta[b]indole)]-2,2'(3H,3'H)-dione | |
| 别名 | Scytonemin |
| 识别 | |
| CAS号 | 152075-98-4 
|
| 性质 | |
| 化学式 | C36H20N2O4 |
| 摩尔质量 | 544.6 g/mol g·mol⁻¹ |
| 外观 | brown solid[1] |
| 溶解性 | 25mg/ml DMSO |
| λmax | 325-425nm nm |
| 若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。 | |
伪枝藻素（英語：Scytonemin）是一种生物色素，由许多藍细菌合成，包括Calothrix sp.[2]、Lyngbya aestuarii[3]等，最早在1849被人发现，但直到1993年才解析了其结构[4]。据信，伪枝藻素对细菌起到了防曬油的作用，吸收325-425 nm的紫外线，并在250 nm有个吸收峰[4]，在暴露在紫外线的情况下才启动它的生物合成[5]。
生物合成
The biosynthesis in Lyngbya aestuarii was recently explored by Balskus, Case, and Walsh. It proceeds by the conversion of L-tryptophan to 3-indole pyruvic acid, followed by coupling to p-hydroxyphenylpyruvic acid. Cyclization of the resultant β-ketoacid yields a tricyclic ketone. Oxidation and dimerization yields the completed natural product. Three scytonemin biosynthetic enzymes are necessary, denoted as ScyA-C.[3]
![Scytonemin biosynthesis in Lyngbya aestuarii.[3]](/wiki/File:Scytonemin_biosynthesis.png)
参考文献
- ^ Scytonemin CAS (152075-98-4). Santa Cruz Biotechnology, Inc. [2011-05-30].
- ^ Dillon, Jesse G.; Castenholz, Richard W. The synthesis of the UV-screening pigment, scytonemin, and photosynthetic performance in isolates from closely related natural populations of cyanobacteria (Calothrix sp.). Environmental Microbiology. 2003, 5 (6): 484–91. PMID 12755715. doi:10.1046/j.1462-2920.2003.00436.x.
- ^ 3.0 3.1 3.2 Balskus, Emily P.; Case, Rebecca J.; Walsh, Christopher T. The biosynthesis of cyanobacterial sunscreen scytonemin in intertidal microbial mat communities. FEMS Microbiology Ecology. 2011: 1–11. doi:10.1111/j.1574-6941.2011.01113.x.
- ^ 4.0 4.1 Proteau, P. J.; Gerwick, W. H.; Garcia-Pichel, F.; Castenholz, R. The structure of scytonemin, an ultraviolet sunscreen pigment from the sheaths of cyanobacteria. Experientia. 1993, 49 (9): 825–9. PMID 8405307. doi:10.1007/BF01923559.
- ^ M. Bandaranayake, Wickramasinghe. Mycosporines: are they nature’s sunscreens?. Natural Product Reports. 1998, 15 (2): 159–72. PMID 9586224. doi:10.1039/A815159Y.
外部链接
- Balskus, Emily P.; Case, Rebecca J.; Walsh, Christopher T. The biosynthesis of cyanobacterial sunscreen scytonemin in intertidal microbial mat communities. FEMS Microbiology Ecology. 2011: no–no. doi:10.1111/j.1574-6941.2011.01113.x.