N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid
[CAS# 10191-18-1]

Identification

• Classification: Organic raw materials >> Organometallic salt
• Name: N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid
• Synonyms: BES; N,N-Bis(2-hydroxyethyl)taurine
• Molecular Formula: C₆H₁₅NO₅S
• Molecular Weight: 213.25
• CAS Registry Number: 10191-18-1
• EC Number: 233-465-5
• SMILES: C(CO)N(CCO)CCS(=O)(=O)O

Properties

• Solubility: 1 M (water 20 °C)
• Melting point: 150-157 °C (dec.)

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H319-H332-H335
• Safety Statements: P233-P260-P261-P264-P270-P271-P280-P301+P312-P302+P352-P304-P304+P340-P305+P351+P338-P312-P321-P330-P332+P313-P337+P313-P340-P362-P403-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin sensitization	Skin Sens.	1	H317

Discovery and Applications

N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, commonly known as BES, is an organic compound widely used as a buffer in biochemical and molecular biology applications. Discovered in the mid-20th century, BES belongs to the Good family of buffers, named after Dr. Norman Good, who discovered and characterized many zwitterionic buffers suitable for biological research.

BES has the molecular formula C6H15NO5S and has two hydroxyethyl groups attached to the central amine and ethanesulfonic acid moieties. This structure enables BES to maintain stable pH in solution, particularly in the range of 6.4 to 7.8. Its zwitterionic nature ensures minimal interference with biochemical reactions, making it a top choice for many laboratory applications.

BES is often used in enzyme assays due to its ability to stabilize pH without interacting with enzyme activity. Its low reactivity with enzyme cofactors and substrates ensures accurate measurements of enzyme kinetics.

BES is an effective buffer in electrophoresis, particularly in polyacrylamide gel electrophoresis (PAGE). It helps maintain pH during protein and nucleic acid isolation processes, resulting in reproducible and reliable results.

In cell culture applications, BES helps maintain the physiological pH of the culture medium, which is essential for cell growth and viability. Its buffering capacity supports a variety of cellular processes, ensuring optimal conditions for in vitro experiments.

BES is used in a variety of biochemical assays and experiments where a stable pH is critical. It is compatible with a wide range of biomolecules, making it suitable for different research needs.

BES offers an optimal buffering range that overlaps with many biological processes, making it suitable for a wide range of applications. It has minimal reactivity with biomolecules, reducing the risk of interfering with experimental results. BES does not significantly chelate metal ions, making it suitable for studies involving metal-dependent enzymes and reactions.

References

2024. Synthesis and Structure of a Copper(II) Complex Based on N-2-(2-pyridyl)Ethyl-2-Aminoethanesulfonic Acid. Journal of Structural Chemistry, 65(7).
DOI: 10.1134/s0022476624070102