四川大学学报（自然科学版）
四川大學學報（自然科學版）
사천대학학보（자연과학판）
JOURNAL OF SICHUAN UNIVERSITY（NATURAL SCIENCE EDITION）
2015年
1期
123-133
,共11页
尼克酰胺核苷%构象稳定性%平滑势能面扫描%格子搜寻方法%密度泛函理论%从头算 Hartree-Fock方法%溶剂效应
尼剋酰胺覈苷%構象穩定性%平滑勢能麵掃描%格子搜尋方法%密度汎函理論%從頭算 Hartree-Fock方法%溶劑效應
니극선알핵감%구상은정성%평활세능면소묘%격자수심방법%밀도범함이론%종두산 Hartree-Fock방법%용제효응
Nicotinamide riboside%Conformational preference%Relaxed potential energy surface scan%GRID search method%Density functional theory%Ab initio Hartree-Fock method%Solvent effect
采用从头算(HF与MP2)和密度泛函理论(DFT)方法,在3-21G 和6-31+G?水平上研究了尼克酰胺核苷(NR)的构象.分别探讨了在气相及液相(水和氯仿)中 NR 分子和一水合物异构体的相对稳定性,分析了溶剂分子的参与对NR异构体的相对稳定性和几何结构参数的影响.结果表明：孤立的NR分子在气相中存在36种稳定构象,其中最稳定的为南式构象NR-S,而最稳定的北式构象为NR-K’,能量比前者高出10.6 kJ/mol (ΔG298K).NR 分子中酰胺基团优势构象为反式,ω,P 或γ参数的改变可以为 NR 分子提供大约8.4~23.7 kJ/mol(ΔG298K )稳定化能.不管是南式还是北式褶皱,最稳定 NR 分子构象中都存在多根分子内氢键,且5’-OH 基团都为顺式构象(γ≈-63°).溶剂效应使一部分NR分子构象相对稳定性降低,而一部分则升高,改变了NR分子各构象的相对稳定性顺序.水分子的加入与酰胺基团结合形成氢键,对NR分子的构型影响较大,而与糖环上羟基结合形成氢键,则影响较小.
採用從頭算(HF與MP2)和密度汎函理論(DFT)方法,在3-21G 和6-31+G?水平上研究瞭尼剋酰胺覈苷(NR)的構象.分彆探討瞭在氣相及液相(水和氯倣)中 NR 分子和一水閤物異構體的相對穩定性,分析瞭溶劑分子的參與對NR異構體的相對穩定性和幾何結構參數的影響.結果錶明：孤立的NR分子在氣相中存在36種穩定構象,其中最穩定的為南式構象NR-S,而最穩定的北式構象為NR-K’,能量比前者高齣10.6 kJ/mol (ΔG298K).NR 分子中酰胺基糰優勢構象為反式,ω,P 或γ參數的改變可以為 NR 分子提供大約8.4~23.7 kJ/mol(ΔG298K )穩定化能.不管是南式還是北式褶皺,最穩定 NR 分子構象中都存在多根分子內氫鍵,且5’-OH 基糰都為順式構象(γ≈-63°).溶劑效應使一部分NR分子構象相對穩定性降低,而一部分則升高,改變瞭NR分子各構象的相對穩定性順序.水分子的加入與酰胺基糰結閤形成氫鍵,對NR分子的構型影響較大,而與糖環上羥基結閤形成氫鍵,則影響較小.
채용종두산(HF여MP2)화밀도범함이론(DFT)방법,재3-21G 화6-31+G?수평상연구료니극선알핵감(NR)적구상.분별탐토료재기상급액상(수화록방)중 NR 분자화일수합물이구체적상대은정성,분석료용제분자적삼여대NR이구체적상대은정성화궤하결구삼수적영향.결과표명：고립적NR분자재기상중존재36충은정구상,기중최은정적위남식구상NR-S,이최은정적북식구상위NR-K’,능량비전자고출10.6 kJ/mol (ΔG298K).NR 분자중선알기단우세구상위반식,ω,P 혹γ삼수적개변가이위 NR 분자제공대약8.4~23.7 kJ/mol(ΔG298K )은정화능.불관시남식환시북식습추,최은정 NR 분자구상중도존재다근분자내경건,차5’-OH 기단도위순식구상(γ≈-63°).용제효응사일부분NR분자구상상대은정성강저,이일부분칙승고,개변료NR분자각구상적상대은정성순서.수분자적가입여선알기단결합형성경건,대NR분자적구형영향교대,이여당배상간기결합형성경건,칙영향교소.
A conformation analysis on the nicotinamide riboside(NR)in gas phase and in water as well as chloroform was performed by ab initio(HF and MP2)and density functional theory(DFT)methods at 3-2 1 G and 6-3 1+G? level.The effects of one-water molecule on relative stabilities,conformational pa-rameters of NR were analyzed.The results indicate that there are 3 6 stable conformers for NR in the gas phase.The south conformer NR-S is the most stable form of all conformations in the gas phase.The most stable north puckering is the conformer NAR-K’,which is about 10.6 kJ/mol (ΔG298K)above the globle minimain NAR-S.The carboxamide group of the NR is preferred in an anti configuration.Varies of the key geometrical parametersω,P orγprovide about 8.4~23.7 kJ/mol(ΔG298K)relative stabilities for NR.The most stable conformer of NR both for south and north puckering adopts a syn configuration withγabout-63°and by doing so,forms stronger intramolecular hydrogen bond interactions.Solvent effects both in water and chloroform change the order of the relative stability of NR,by decreasing or in-creasing the relative stabilities of NR molecules.The addition of one-water molecule will influence great-ly the conformational parameters of NR due to the stronger hydrogen bond interactions with carboxam-ide group of NR,while this influence will be negligible if the hydrogen bonds formed between water molecule and hydroxy groups of furanose ring.
