The Ca(2+)-ATPase in the sarcoplasmic reticulum of skeletal muscle reacts with o-phthalaldehyde (OPA) to form a fluorescent isoindole product. The stoichiometry of labelling of the ATPase is 9 nmol of isoindole/mg of ATPase, corresponding to a 1:1 molar ratio of isoindole: ATPase. There is no evidence for any intermolecular cross-linking. Isoindole formation is faster in the presence of methyla...

THE TITLE COMPOUND [SYSTEMATIC NAME: 2-(1H-1,2,3-benzotriazol-1-ylmeth-yl)isoindole-1,3-dione], C(15)H(10)N(4)O(2), was prepared by the reaction of 1H-benzotriazole and 2-bromo-methyl-isoindole-1,3-dione. The benzotriazole and isoindole units are almost planar and make a dihedral angle of 70.2 (1)° (mean planes include C and N atoms). A weak C-H⋯O intra-molecular hydrogen bond involving a carbo...

In the title compound, C(16)H(16)N(4)O(6), the planes of the isoindole and dinitro-benzene groups make a dihedral angle between of 84.15 (8)°. The N atom of the isoindole group is displaced by 0.2937 (3) Å from the plane through the remaining atoms. An intra-molecular N-H⋯O inter-action occurs. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds occur.

Chicken liver mitochondrial phosphoenolpyruvate carboxykinase is inactivated by o-phthalaldehyde. The inactivation followed pseudo first-order kinetics, and the second-order rate constant for the inactivation process was 29 M-1 s-1 at pH 7.5 and 25 degrees C. The modified enzyme showed maximal fluorescence at 427 nm upon excitation at 337 nm, consistent with the formation of isoindole derivativ...

Abstract Background Since Nicotiana tabacum (tobacco) has important significance to humans for their medicinal uses, find antivirus activities inhibitors from tobacco, increase its value, and comprehensive utilization of by-products, our group had investigated the chemical constituents stems Y-202, a cultivar tobacco which high resistance mosaic virus (TMV). Results Four new isoindolinone-type ...

In the title compound, C(10)H(6)F(3)NO(2), the isoindole ring system is planar, the maximum atomic deviation being 0.012 (2) Å. The C-C bond of the trifluoro-ethyl group is twisted with respect to the isoindole ring by a dihedral angle of 62.58 (17)°. Weak inter-molecular C-H⋯O and C-H⋯F hydrogen bonding is present in the crystal structure.

In the title compound, C(15)H(11)NO(3), the dihedral angle between the meth-oxy-benzene and isoindole ring systems is 70.21 (3)°. The meth-oxy C atom is close to being coplanar with its attached ring [deviation = 0.133 (2) Å] and is oriented away from the isoindole moiety. In the crystal, inversion dimers linked by pairs of C-H⋯O hydrogen bonds generate R(2) (2)(10) loops. Further C-H⋯O inter-a...

Guanosine cyclic 3',5'-monophosphate (cGMP) dependent protein kinase is inactivated by o-phthalaldehyde. The loss of phosphotransferase activity following treatment with o-phthalaldehyde was rapid, and the second-order rate constant at 25 degrees C and pH 7.3 was 35 M-1 s-1. The inactivation reaction did not follow saturation kinetics. The cGMP-dependent protein kinase was protected from inacti...

This review highlights the chemical and biological aspects of natural products containing an oxidized or reduced isoindole skeleton. This motif is found in its intact or modified form in indolocarbazoles, macrocyclic polyketides (cytochalasan alkaloids), the aporhoeadane alkaloids, meroterpenoids from Stachybotrys species and anthraquinone-type alkaloids. Concerning their biological activity, m...

Yeast hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1), a homodimer, was rapidly and irreversibly inactivated by o-phthalaldehyde at 25 degrees C (pH 7.3). The reaction followed pseudo-first-order kinetics over a wide range of the inhibitor concentration. The second-order-rate constant for the inactivation of hexokinase was estimated to be 45 M-1.s-1. Hexokinase was protected more by ...