We discuss the truncation of low energy effective action of QCD below the c
hiral symmetry breaking (CSB) scale, including all operators of dimensional
ity less or equal to 6 which can be built with quark and chiral fields. We
perform its bosonization in the scalar, pseudoscalar, vector and axial-vect
or channels in the large-N-c and leading-log approximation. Constraints on
the coefficients of the effective lagrangian are derived from the requireme
nt of Chiral Symmetry Restoration (CSR) at energies above the CSB scale in
the scalar-pseudoscalar and vector-axial-vector channels, from matching to
QCD at intermediate scales, and by fitting some hadronic observables. In th
is truncation two types of pseudoscalar states (massless pions and massive
H-mesons), as well as a scalar, vector and axial-vector one arise as a cons
equence of dynamical chiral symmetry breaking. Their masses and coupling co
nstants as well as a number of chiral structural constants are derived. A r
easonable fit of all parameters supports a relatively heavy scalar meson (q
uarkonium) with the mass similar to 1 GeV and a small value of axial pion-q
uark coupling constant g(A) similar or equal to 0.55.