Design and Synthesis of Novel 1,2,3-Triazole- and 2-Isoxazoline-Based Bis-Heterocycles as Immune Potentiators

A series of novel bis-heterocycles encompassing isoxazolines and triazoles were synthesized through a novel one-pot procedure that involves in situ generation of nitrile oxide and its 1,3-dipolar cycloaddition to variedly substituted acrylates. The synthesized bis-heterocycles (8a–l) were subjected to in vitro lymphocyte proliferation assays followed by in vivo studies of the more active compounds (8g and 8h) to assess their influence on various aspects of the immune system like ex vivo splenocyte proliferation (T- and B-cell proliferation), antibody production (HA titer), delayed-type hypersensitivity reaction, T-cell subtypes (CD4 and CD8), cytokine production (IL-2, IFN-γ, and IL-4), NO (macrophage) production, and toxic effects. The results from the in vitro and in vivo studies establish that the tested compounds 8g and 8h possess excellent immunopotentiating activity.