フォスフォラン中のpK(a) の理論的評価:フォスファートエステルの水解への影響

Xabier Lopez¹, Michael Schaefer, Annick Dejaegere

¹Kimika Fakultatea, Euskal Herriko Unibertsitatea, P.K. 1072, 20080 Donostia, Spain.

Journal of the American Chemical Society

|May 2, 2002

まとめ

この研究では,リン酸エステル水解の重要な要因であるエチレンフォスフォランの酸度を計算します. この結果は,実験データと一致する重要なpK (a) 値を提供し,化学反応を理解するのに役立ちます.

科学分野:

コンピューティング・ケミストリー
物理有機化学物理有機化学

背景:

リン酸塩の酸塩特性 (pK(a)) を理解することは,リン酸エステル水解のメカニズムを解釈するために重要である.
リン酸塩は,リン酸塩基を含む様々な生化学的および化学的プロセスにおいて重要な役割を果たします.

研究の目的:

モデルフォスフォラン,特にエチレンフォスフォランの酸解離定数 (pK(a)) を計算する.
リン酸エステル水解に関連するpK (a) 値に関する理論的洞察を提供するため.

主な方法:

密度関数理論 (DFT) を利用して,ガス相プロトネーションエネルギーを計算した.
溶解修正を計算するために連続体介電法を使用した.
相対的なpK (a) 評価の基準としてディメチルリン酸を使用した最適化されたヴァン・デル・ワールズ半径.

主要な成果:

エチレンフォスフォランの計算されたpK (pK1) (a) とpK (pK2) (a) はそれぞれ7.9と14.3です.
これらの計算された値は,以前に提案された実験値の範囲内にあります.
この結果は,フォスフォランpK (a) の決定のための計算アプローチの妥当性を裏付けています.

結論:

エチレンフォスフォランの計算されたpK (a) 値は,実験観察と一致しています.
これらの発見は,リン酸エステル水解を理解するための重要なメカニズム的意味を持つ.
この研究は,リン酸塩酸塩の性質を予測するための計算戦略を検証しています.

さらに関連する動画

08:59

Defining Substrate Specificities for Lipase and Phospholipase Candidates

Published on: November 23, 2016

08:21

Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method

Published on: May 18, 2018

関連する概念動画

01:01

Phosphodiester Linkages

Overview
Phosphodiester bond forms when a phosphoric acid molecule (H3PO4) links with two hydroxyl groups (–OH) of two other molecules, forming two ester bonds. Two water molecules are released in this process. The phosphodiester bond is commonly found in nucleic acids (DNA and RNA) and plays a critical role in their structure and function.
Phosphodiester Bonds Link Nucleotides Together
DNA and RNA are polynucleotides or long chains of nucleotides that are linked together. A nucleotide is...

01:02

Phosphorylation

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...

02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...

01:13

Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis

Hydrolysis of esters under acidic conditions proceeds through a nucleophilic acyl substitution. In the presence of excess water, the reaction proceeds in a reversible manner, forming carboxylic acids and alcohols.
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...

01:26

Variables Affecting Phosphorescence and Fluorescence

Fluorescence and phosphorescence are essential phenomena in fields like analytical chemistry, biological imaging, and materials science, where they detect molecular properties and visualize cellular structures. Understanding the variables that influence these luminescent behaviors is crucial for maximizing accuracy and efficiency in their applications. These variables can broadly be grouped into chemical structure, solvent properties, and external conditions, each playing a distinct role in...

01:14

Photoluminescence: Applications

Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...

関連する実験動画