Crystal structure and spectroscopic analysis of the compatible solute nγ-acetyl-l-2,4-diaminobutyric acid

Compatible solutes are low molecular weight, highly water-soluble and neutrally net-charged molecules with various protective functionalities that accumulate and are produced in microorganisms. Their multi-purpose functionalities, also adaptable in vitro, make them potential components in healthcare and cosmetic products. One promising but insufficiently examined representative of this molecule class is Nγ-acetyl-L-2,4-diaminobutyric acid (γ-NADA), the metabolic precursor of ectoine. Here, we demonstrate the crystallization ability of γ-NADA by using cooling crystallization in aqueous solvents and find that it forms rod-shaped crystals. According to a single crystal structure determination, γ-NADA is orthorhombic with space group P2₁ 2₁ 2₁ and a = 5.3647(1), b = 8.3652(2), c = 16.9149(5) Å, Z = 4, R₁ = 3.48%, wR₂ = 7.33% (all data). Additionally, γ-NADA is analyzed via Raman, IR,¹ H, and¹³ C NMR spectroscopy.