17:15 〜 18:45
[MIS07-P03] 隕石母天体内における水熱過程での単糖類生成について、カンラン石による影響の検討
キーワード：隕石母天体、単糖類、糖、水熱過程、カンラン石
1. Introduction
How monosaccharides were formed in the prebiotic environment is not uncovered, despite many theories have been proposed. One of them is that monosaccharides were formed in space and then brought to the earth via meteorites and interplanetary dust particles.
The source of the meteorites, i.e., the meteorite parent bodies, expected to initially contain materials such as water and formaldehyde derived from molecular clouds, as well as energy sources such as heat and gamma rays from radioactive elements, making the parent bodies a plausible site for monosaccharide production [1-3]. Indeed, monosaccharides have been reported in meteorites [4].
The monosaccharides are synthesized by polymerization of formaldehyde in aqueous solution, so called a formose reaction. This reaction is usually catalyzed by divalent metal ions such as calcium hydroxide. Not divalent metal ions but other base catalysts such as ammonia could be used [5] (formose-type reaction).
We have been conducting in vitro heating experiments on formose-type reactions in meteorite parent bodies, and in the course of the experiments, we felt it necessary to take into account the influence of minerals that existed in the environment of the meteorite parent bodies. Therefore, the purpose of this study was to experimentally investigate the effect of minerals on the formose-type reaction.
2. Methods
Heating experiments was performed on a solution consisting of water, formaldehyde, ammonia, and methanol to which olivine powder was added. After derivatization was performed on the heated sample, GC/MS analysis was performed and the amount of monosaccharides were quantified from the chromatograms obtained. The same experiment was also conducted when olivine was not added to the aqueous solution, and the results were compared to verify whether there was a difference in the amount of monosaccharides produced.
3. Results and discussion
The results of the experiments showed that the amount of monosaccharides produced tended to increase in the presence of olivine. Since no monosaccharides were detected when the same experiment was conducted with olivine in water, the contamination from olivine was minimum, and this change is considered to be the result of catalytic effect of olivine on the formation of monosaccharides from the aqueous solutions.
Although the mechanism by which olivine increased the monosaccharides production is currently not well understood, simulation results indicate that magnesium ions in olivine dissolve in aqueous solution and act as a catalyst for formose-type reactions [6]. Thus, the amount of magnesium ions in the heated samples will be investigated.
4. References
[1] J.M. Greenberg and A. Li, Silicate core organic refractory mantle particles as interstellar dust and as aggregated in comets and stellar disks, Adv. Space Res., 19, 981-990, (1997)
[2] C. Hayashi et al., Formation of the solar system, In Protostars and planets Ⅱ, pp. 1100-1153, (1985)
[3] Y. Kebukawa et al., Exploring the potential formation of organic solids in chondrites and comets through polymerization of interstellar formaldehyde, The Astrophysical Journal, 771, 19, (2013)
[4] Y. Furukawa et al., Extraterrestrial ribose and other sugars in primitive meteorites, PNAS, 116, 24440-24445, (2019)
[5] C. Meinert et al., Ribose and related sugars from ultraviolet irradiation of interstellar ice analogs, Science, 352, 208-212, (2016)
[6] A. Omran et al., Serpentinization-Associated Mineral Catalysis of the Protometabolic Formose System, Life, 13, 1297, (2023)
How monosaccharides were formed in the prebiotic environment is not uncovered, despite many theories have been proposed. One of them is that monosaccharides were formed in space and then brought to the earth via meteorites and interplanetary dust particles.
The source of the meteorites, i.e., the meteorite parent bodies, expected to initially contain materials such as water and formaldehyde derived from molecular clouds, as well as energy sources such as heat and gamma rays from radioactive elements, making the parent bodies a plausible site for monosaccharide production [1-3]. Indeed, monosaccharides have been reported in meteorites [4].
The monosaccharides are synthesized by polymerization of formaldehyde in aqueous solution, so called a formose reaction. This reaction is usually catalyzed by divalent metal ions such as calcium hydroxide. Not divalent metal ions but other base catalysts such as ammonia could be used [5] (formose-type reaction).
We have been conducting in vitro heating experiments on formose-type reactions in meteorite parent bodies, and in the course of the experiments, we felt it necessary to take into account the influence of minerals that existed in the environment of the meteorite parent bodies. Therefore, the purpose of this study was to experimentally investigate the effect of minerals on the formose-type reaction.
2. Methods
Heating experiments was performed on a solution consisting of water, formaldehyde, ammonia, and methanol to which olivine powder was added. After derivatization was performed on the heated sample, GC/MS analysis was performed and the amount of monosaccharides were quantified from the chromatograms obtained. The same experiment was also conducted when olivine was not added to the aqueous solution, and the results were compared to verify whether there was a difference in the amount of monosaccharides produced.
3. Results and discussion
The results of the experiments showed that the amount of monosaccharides produced tended to increase in the presence of olivine. Since no monosaccharides were detected when the same experiment was conducted with olivine in water, the contamination from olivine was minimum, and this change is considered to be the result of catalytic effect of olivine on the formation of monosaccharides from the aqueous solutions.
Although the mechanism by which olivine increased the monosaccharides production is currently not well understood, simulation results indicate that magnesium ions in olivine dissolve in aqueous solution and act as a catalyst for formose-type reactions [6]. Thus, the amount of magnesium ions in the heated samples will be investigated.
4. References
[1] J.M. Greenberg and A. Li, Silicate core organic refractory mantle particles as interstellar dust and as aggregated in comets and stellar disks, Adv. Space Res., 19, 981-990, (1997)
[2] C. Hayashi et al., Formation of the solar system, In Protostars and planets Ⅱ, pp. 1100-1153, (1985)
[3] Y. Kebukawa et al., Exploring the potential formation of organic solids in chondrites and comets through polymerization of interstellar formaldehyde, The Astrophysical Journal, 771, 19, (2013)
[4] Y. Furukawa et al., Extraterrestrial ribose and other sugars in primitive meteorites, PNAS, 116, 24440-24445, (2019)
[5] C. Meinert et al., Ribose and related sugars from ultraviolet irradiation of interstellar ice analogs, Science, 352, 208-212, (2016)
[6] A. Omran et al., Serpentinization-Associated Mineral Catalysis of the Protometabolic Formose System, Life, 13, 1297, (2023)