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 N gamma-acetyl-L-2,4-diaminobutyric acid (gamma-NADA), the metabolic precursor of ectoine. Here, we demonstrate the crystallization ability of gamma-NADA by using cooling crystallization in aqueous solvents and find that it forms rod-shaped crystals. According to a single crystal structure determination, gamma-NADA is orthorhombic with space group P2(1)2(1)2(1) and a = 5.3647(1), b = 8.3652(2), c = 16.9149(5) angstrom, Z = 4, R-1 = 3.48%, wR(2) = 7.33% (all data). Additionally, gamma-NADA is analyzed via Raman, IR, H-1, and C-13 NMR spectroscopy.