據(jù)2月19日的《科學(xué)》雜志報道說,，新的研究證明了硅酸鹽離子是如何曾經(jīng)在一個原始的地球上使得復(fù)雜糖分子的增長變得容易,。研究人員說，這一發(fā)現(xiàn)擴(kuò)大了生命起源的可能的環(huán)境范圍,。
Joseph Lambert及其同僚開展了一系列的在室溫中用簡單的糖分子進(jìn)行的化學(xué)反應(yīng),。他們發(fā)現(xiàn)，硅酸鹽離子是穩(wěn)定那些基本反應(yīng)物從而形成更復(fù)雜的糖的關(guān)鍵,。在硅酸鈉存在的情況下,，簡單的2碳和3碳糖分子會自動地形成較大的4碳和6碳化合物。這一觀察為一種經(jīng)典的甲醛聚糖反應(yīng)（即從甲醛可制造出復(fù)雜的糖分子）可為這個星球上的生命提供所需的必要建材提供了證據(jù),。從理論上說,，簡單的甲醛分子可形成像核糖這樣的復(fù)雜糖分子，而這些糖分子最終會形成RNA,。然而,，這些反應(yīng)究竟是如何在數(shù)十億年之前在地球上完成的一直是存在著許多爭議的話題。由于硅酸鹽離子在地球早期的表層水中相對比較豐富,，這一發(fā)現(xiàn)提示，甲醛聚糖類的反應(yīng)是合成復(fù)雜糖分子的一種可行的途徑,，可能也是地球上生命開始的途徑,。（生物谷Bioon.com）
生物谷推薦原始出處：
Science 19 February 2010:DOI: 10.1126/science.1182669
The Silicate-Mediated Formose Reaction: Bottom-Up Synthesis of Sugar Silicates
Joseph B. Lambert,* Senthil A. Gurusamy-Thangavelu, Kuangbiao Ma
Understanding the mechanism of sugar formation and stabilization is important for constraining theories on the abiotic origin of complex biomolecules. Although previous studies have produced sugars from small molecules through the formose and related reactions, the product mixtures are complex and unstable. We have demonstrated that simple two- and three-carbon molecules (glycolaldehyde and glyceraldehyde), in the presence of aqueous sodium silicate, spontaneously form silicate complexes of four- and six-carbon sugars, respectively. Silicate selects for sugars with a specific stereochemistry and sequesters them from rapid decomposition. Given the abundance of silicate minerals, these observations suggest that formose-like reactions may provide a feasible pathway for the abiotic formation of biologically important sugars, such as ribose.
Department of Chemistry, Northwestern University, Evanston, IL 60208, USA.
