14048-37-4Relevant academic research and scientific papers
Synthesis of carbohydrates in mineral-guided prebiotic cycles
Kim, Hyo-Joong,Ricardo, Alonso,Illangkoon, Heshan I.,Kim, Myong Jung,Carrigan, Matthew A.,Frye, Fabianne,Benner, Steven A.
experimental part, p. 9457 - 9468 (2011/08/04)
One present obstacle to the "RNA-first" model for the origin of life is an inability to generate reasonable "hands off" scenarios for the formation of carbohydrates under conditions where they might have survived for reasonable times once formed. Such scenarios would be especially compelling if they deliver pent(ul)oses, five-carbon sugars found in terran genetics, and exclude other carbohydrates (e.g., aldotetroses) that may also be able to function in genetic systems. Here, we provide detailed chemical analyses of carbohydrate premetabolism, showing how borate, molybdate, and calcium minerals guide the formation of tetroses (C4H8O4), heptoses (C7H14O7), and pentoses (C 5H10O5), including the ribose found in RNA, in "hands off" experiments, starting with formaldehyde and glycolaldehyde. These results show that pent(ul)oses would almost certainly have formed as stable borate complexes on the surface of an early Earth beneath a humid CO2 atmosphere suffering electrical discharge. While aldotetroses form extremely stable complexes with borate, they are not accessible by pathways plausible under the most likely early Earth scenarios. The stabilization by borate is not, however, absolute. Over longer times, material is expected to have passed from borate-bound pent(ul)oses to a branched heptulose, which is susceptible to Cannizzaro reduction to give dead end products. We show how this fate might be avoided using molybdate-catalyzed rearrangement of a branched pentose that is central to borate-moderated cycles that fix carbon from formaldehyde. Our emerging understanding of the nature of the early Earth, including the presence of hydrated rocks undergoing subduction to form felsic magmas in the early Hadean eon, may have made borate and molydate species available to prebiotic chemistry, despite the overall "reduced" state of the planet.
Beneficial effect of internal hydrogen bonding interactions on the β-fragmentation of primary alkoxyl radicals. Two-step conversion of D-xylo- and D-ribofuranoses into L-threose and D-erythrose, respectively
Hernandez-Garcia, Luis,Quintero, Leticia,Sanchez, Mario,Sartillo-Piscil, Fernando
, p. 8196 - 8201 (2008/02/13)
(Chemical Equation Presented) Primary alkoxyl free radicals were generated from their readily synthesized N-phthalimido derivatives under reductive conditions. Primary alkoxyl radicals derived from their corresponding xylo- and ribofuranose derivatives underwent, exclusively, an unusual β-fragmentation affording L-threose and D-erythrose derivatives, respectively. This occurs because the alkoxyl radical is capable of achieving an internal hydrogen-bonding interaction leading to a stable six-membered ring intramolecular hydrogen-bonded structure. When the hydroxyl group is protected, the β-fragmentation pathway is prevented and the hydrogen atom transfer (HAT) pathway occurs. Computational studies provided strong support for the experimental observations.
Aldol Reaction between Small Sugars. Preparation of DL-threo-2-Pentulose and DL-lyxo-3-Hexulose and their Isolation as O-Isopropylidene Derivatives
Morgenlie, Svein
, p. 745 - 748 (2007/10/02)
The improved diastereoselectivity obtained with strongly basic anion-exchange resin as catalyst in aldol condensation between two-, three- and four-carbon "sugars" has been utilised in the preparation of DL-threo-2-pentulose and DL-lyxo-3-hexulose, which were isolated as their O-isopropylidene derivatives.A possible reason for the observe preference of formation of the lyxo-diastereomer in condensation between glycolaldehyde and glycero-tetrulose is suggested.
