NEW NITRIC OXIDE-RELEASING ZWITTERIONS DERIVED FROM POLYAMINES

The reaction of nitric oxide (NO) with polyamines has been studied, resulting in the discovery of a new type of NO-releasing compound having the structure RN[N(O)NO]-(CH2)xNH2+R' (3). Numerous examples of these zwitterionic polyamine/NO adducts have been prepared and found to be very stable solids which release NO in solution. The new compounds contain as much as 45% NO by weight and are capable of releasing it all at rates which have been shown to vary in a predictable way with structure. The half-lives in buffered aqueous solution at pH 7.4 and 22-degrees-C were shown to vary from extremely short (1.3 min for diamine 8, MeN[N(O)NO]-(CH2)4NH2+Me) to very long (56 h for triamine 18, H2NCH2CH2N[N(O)NO]-CH2CH2NH3+). In general, the longest half-lives were achieved by triamine/NO adducts and derivatives of ethylenediamine (x = 2). For any given value of x, a small increase in the size of R resulted in a relatively large increase in half-life but changes in R' appeared to have little effect. Data are presented which should allow the selection of the proper compounds to achieve a wide range of desired NO generation rates. These NO-containing zwitterions should prove to be important resources in studies of the biology of NO and may also have important pharmaceutical and chemical applications.