  In [ZH], R.B. Zhang found a way to link certain formal deformations of the
Lie algebra o(2l+1) and the Lie superalgebra osp(1,2l). The aim of this article
is to reformulate the Zhang transformation in the context of the quantum
enveloping algebras "\`a la" Drinfeld-Jimbo and to show how this construction
can explain the main theorem of [GL2]: the annihilator of a Verma module over
the Lie superalgebra osp(1,2l) is generated by its intersection with the
centralizer of the even part of the enveloping algbra.
