Effects of gamma-ray for production of sugars by formose-type reaction simulating aqueous alteration in meteorite parent bodies

Abstract

Sugars and sugar derivatives play important biological roles. As a prebiotic sugar formation reaction, the “formose reaction” has been attracted attention. Formose reaction is the reaction that makes various sugars from aldehydes with base catalysts. Meteorite parent bodies are considered to be among the places where the formose-type reaction may have occurred. In order to simulate reactions in the meteorite parent bodies, 3 kinds of the starting mixtures were prepared: (1) formaldehyde : H₂O = 10 : 100, (2) glycolaldehyde : glyceraldehyde : H₂O = 0.009 : 0.09 : 100, (3) formaldehyde : glycolaldehyde : H₂O = 3.6 : 1.8 : 100 (molar ratios). 200 µL of each mixture was heated or irradiated by gamma-ray. An aliquot of each product was derivatized, and analyzed by GC/MS. Aldoses were detected in all the products. In the same starting material, varieties and amounts of aldose produced by gamma-ray irradiation tended to be greater than those of heated samples.