boldenone is structurally similar to dbol, some modifications, yet it is nothing like dbol. The esterification is completely different all together.
Testosterone is the parent hormone, this can be presented in a base (TNE - test 'no ester'), or with some ester attached to it: acetate, propionate, phenylpropionate, cypionate, enanthate, decanoate, isocoproate, undecanoate, testosterone cyclohexanecarboxylate... (maybe a few more). The ester takes up some usable space of the compound - so if you weighed out 200mg of test base it would be 200 mg of testosterone. 200mg of test propionate is 167.44mg of testerone - the rest being the propionate ester. 200mg of test cypionate is 139.80mg of testosterone with the rest being the cypionate ester.
The ester dictates the release into the body; half-life being the common metric. If you injected the same amount of each of the above 3 examples into your body at the same amount of each week, your peak blood plasma concentrations of cypionate would reach the highest value due to its' slower release into the body. Faster acting esters tend to contain more parent hormone content than longer acting esters, and they also tend to be more painful. Boldenone propionate was making many people sick. In fact, I've never seen a 10ml vial priced as low as I have seen bold prop priced when a source is trying to get rid of it because it sucks so bad.
As far as the nandrolone base? I have not seen any uses of it - I can only assume that it does not have a lot of utility in the bodybuilding world without being esterfied.