4-Methylumbelliferyl Sulfate Potassium Salt（CAS:15220-11-8）

Met-enkephalin analog found in opioid extracts of brain and adrenal chromaffin cells that is an artifact generated by trichloroacetic acid extraction. MUS is used as a fluorimetric substrate for arylsulphatase enzyme.
Subsitution of the hydroxyl group of 4-methylumbelliferone (4-methyl-7-hydroxy-coumarin) causes the excitation wavelength of the umbelliferone to shift to shorter values and also brings about a decrease in fluorescence.
Fluorescence: max. Abs = 334 mm; max. Em. = 370 mm