In the context of the 331 models, we consider constraints on the extra neutral boson Z ′ predicted by the model, where three different quark family assignments are identified. Using the ansatz of Matsuda as an specific texture for the quark mass matrices, we obtain allowed regions associated with the Z-Z' mixing angle, the mass of the Z ′ boson and the parameter β which determines different 331 models. The Z 1 and Z 2 decays with and without flavor changing are also considered. The flavor changing decays of the Z 1 boson into quarks at tree level are highly suppressed by the Z − Z ′ mixing angle, obtaining the same order of magnitude as the standard model prediction at one loop level. The Z 2 decay widths are calculated with and without flavor changing, where oblique radiative corrections at one loop accounts for about 1% − 4% deviations. *

The quark mass matrices ansatze proposed by Fritzsch, Du-Xing and Fukuyama-Nishiura in the framework of the general two Higgs doublet model are studied. The corresponding Yukawa matrices in the flavor basis in the different cases considered are discussed. The corresponding Cabbibo-Kobayashi-Maskawa matrix elements are computed in all cases and compared with their experimental values. The complex phases of the ansatze are taken into account and the CP violating phase δ is computed. Finally, in order to observe the influence of the different kind of textures of Yukawa coupling matrices considered, some phenomenology of two body decays of the top quark, the lightest Higgs boson and the charged Higgs boson is discussed.

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