Probe for measuring phytase activity

A myo-inositol derivative compound of the following nominal formula:

• Wherein R1, R2, R3 and R4 are identical, and are selected from the group consisting of PO3H2, PO3Na2, PO3K2, PO3Li2, PO3Ca, PO3Mg, PO3(NH4)2, PO3(RNH3)2, PO3(R2NH2)2, PO3(R4N)2, PO(OR)2, H, COZ and BHPP, where R is benzyl or alkyl of 1 to 6 carbon atoms and Z is an alkyl or arylalky group that provides a cleavable ester protecting group;
• R5 is selected from the group consisting of H, benzyl, 4-methoxybenzyl, COZ, PO3H2, PO3Na2, PO3K2, PO3Li2, PO3Ca, PO3Mg, PO3(NH4)2, PO3(RNH3)2, PO3(R2NH2)2, PO3(R4N)2, PO(OR)2, and BHPP, where R is benzyl or alkyl of 1 to 6 carbon atoms and Z is an alkyl or arylalky group that provides a cleavable ester protecting group;
• X is selected from the group consisting of CH2, CH2CH2O, and CH2CH2CH2O;
• n is an integer from 1 to 8;
• L1 is a single bond or CH2;
• L2 is selected from the group consisting of a single bond, CONH, CH2CONH, CH2CH2CONH, CH2CH2NHCO, CH2CH2NHCONH, CH2CH2NHCSNH, CH2CH2NHSO2, CH2CH2CH2NHCO, CH2CH2CH2NHCONH, CH2CH2CH2NHCSNH, CH2CH2CH2NHSO2, NHCO, NHCONH, NHCSNH, OCONH, CH2, CH2CH2, CH2CH2O, CH2CH2S, CH2CH2NH, CH2CH2CH2, CH2CH2CH2O, CH2CH2CH2S, CH2CH2CH2NH, and NH—SO2;
• and
• R6 is selected from the group consisting of UV-visible chromophores, UV-chromophores, fluorescent moieties, and radiolabeled moieties.