Session 6 environmental biotechnology

Applied Biochemistry and Biotechnology -     

Session 5 Environmental biotechnology

Applied Biochemistry and Biotechnology -     

Session 5 emerging topics in industrial biotechnology

Applied Biochemistry and Biotechnology -     

Structure and stability of B6, B,and B clusters

We investigated various isomers of B₆, B, and B clusters with ab initio [Hartree–Fock (HF), MP2)] and density functional theory (DFT) methods. Ten B₆ isomers, 6 B isomers, and 6 B isomers are determined to be local minima on their potential energy hypersurfaces by the HF, B3LYP, B3PW91, and MP2 methods. Fourteen of these structures are first reported. The most stable neutral B₆ cluster is the capped pentagonal pyramid (C_5v), in agreement with the results reported previously. Hexagon B (C_2h) isomer and fan‐shaped B (C_2v) isomer are found to be the most stable on the cationic and anionic energy hypersurfaces, respectively. Natural bond orbital analysis suggests that there are three‐centered bonds in the most stable B₆ neutral and ionic clusters. The multicentered bonds are responsible for the special stability of the lowest‐energy isomer. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 269–278, 2003     

RNA表观遗传修饰——N~6-甲基腺嘌呤与植物的生长发育

RNA表观遗传修饰N~6-甲基腺嘌呤(m~6A)是真核生物信使RNA(mRNA)上存在的最为广泛的中间化学修饰。它在哺乳动物中存在较为广泛,证实m~6A为mRNA上的动态可逆化修饰,它由甲基转移酶复合物(编码器)催化形成,同时可以被去甲基酶(消码器)氧化去甲基;m~6A可以被结合蛋白(读码器)识别,进而调控mRNA的剪接、稳定性、翻译、出核等。相较之下,m~6A在植物中的研究较少。本文将简要回顾目前m~6A的研究进展,重点综述m~6A在植物中的研究结果,展望m~6A在植物生长发育和应对外界刺激时的潜在重要功能。     

Vitamin B6 analogs

4-Acetyl-3-hydroxy-5-hydroxymethyl-2-methylpyridine 5-phosphate (IV) was synthesized by oxidation of 3-hydroxy-5-hydroxymethyl-4-(-hydroxyethyl)-2-methylpyridine 5-phosphate (III) with chromic anhydride. Compound III was obtained by phosphorylation of 3-hydroxy-5-hydroxymethyl-4-(-hydroxyethyl)-2-methylpyridine with polyphosphoric acid (PPA). The UV and PMR spectra of the synthesized compounds were studied.See [1] for communication XIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 499–503, April, 1971.The authors sincerely thank Academician A. E. Braunshtein for his constant interest in this work, V. I. Ivanov and A. F. Vanin for their fruitful discussions, and K. F. Turchin and I. I. Chervin for kindly providing the possibility for obtaining the PMR spectra.     

Vitamin B6 analogs

3-O-Methylpyridoxal phosphate and 3-O-methylpyridoxamine phosphate were synthesized and their UV spectra were studied.See [7] for communication IX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 368–372, March, 1971.     

6A6B, 6A6C,and 6A6D-ditosylates of β-cyclodextrin

Regio-isomers, 6A6B, 6A6C, and 6A6D-ditosylates of β-cyclodextrin prepared by the reaction of β-cyclodextrin with tosyl chloride were easily and effectively separated through reversed phase column chromatography and assigned.