Esterase Activity of Chymotrypsin on O-DNP-L-Tyrosine Ethyl Ester Substrates

Nonpeptide-Based Small-Molecule Probe for Fluorogenic and Chromogenic Detection of Chymotrypsin

“…Chymotrypsin (EC 3.4.21.1), one of the most common serine proteases, is involved in many physiological processes, including digestion of dietary proteins, necrosis, and apoptosis. − In addition, it has been implied in the pathogenesis of various diseases, such as pancreatic fibrosis, maldigestion, diabetes mellitus, hypertension, inflammation, and many types of cancer, particularly pancreatic cancer. − Moreover, the chymotrypsin itself is a medicine for reducing redness, swelling, or damages that are associated with various situations like infection and surgery. , Therefore, the detection of chymotrypsin activity is highly important in drug discovery and clinical diagnostics.…”

“…Solvents were dried in a routine way and redistilled. 1 H NMR and 13 C NMR spectra were recorded in DMSO-d 6 on a Varian Mercury 400, 500, and 600 MHz spectrometer, and resonances (δ) are given in ppm relative to tetramethylsilane (TMS). The following abbreviations were used to designate chemical shift mutiplicities: s = singlet, d = doublet, t = triplet, m = multiplet, br = broad, q = quartet.…”

“…The solution was acidified to pH = 5 with 1 M HCl, and the resulting precipitate was filtered, washed with water, and dried to give M2 as a yellow solid (yield: 82%). 1 .75 (q, J = 9.2 Hz, 2H), 3.82 (s, 3H), 2.58 (t, J = 6.6 Hz, 2H), 1.66 (q, J = 7.2 Hz, 2H), 0.97 (t, J = 6.9 Hz, 3H). 13 6.70 (q, J = 16.4 Hz, 2H), 3.84 (s, 3H), 3.54 (t, J = 6.0 Hz, 2H), 2.81 (t, J = 7.2 Hz, 2H), 2.30 (quintuplet, J = 6.9 Hz, 2H).…”

“…The combined residue was subjected to silica gel chromatography to give 2 as brown oil. 1 H NMR (500 MHz, DMSO-d 6 ): δ 8.06 (d, J = 7.5 Hz, 1H), 7.79 (t, J = 5.0 Hz, 1H), 7.74 (d, J = 6.0 Hz, 1H), 7.34− 7.19 (m, 6H), 7.05 (s, 1H), 6.95 (d, J = 2.5 Hz, 1H), 6.86 (d, J = 9.0 Hz, 1H), 6.76−6.70 (m, 3H), 3.81 (s, 3H), 3.08−2.98 (m, 1H), 2.87−2.83 (m, 1H), 2.66−2.59 (m, 1H), 1.24 (d, J = 7.0 Hz, 3H). 13 Determination of Quantum Yield.…”

“…The combined residue was subjected to silica gel chromatography to give probe 1 as white solid (yield: 74%). mp 87−88 °C 1. H NMR (600 MHz, DMSO-d 6 ):…”