The one obtained in greater quantity was subjected to various chemical transformations, generating a library of 16 compounds, epoxylathyrol (10), epoxyboetiranes (14, 21–28) and epoxycarbamoylboetiranes B and C (29–30) (Figure 4), which were evaluated as P-gp-mediated MDR reversers at non-cytotoxic doses in L5178Y ABCB1 transfected mouse T-lymphoma cells, by the accumulation of rhodamine-123 assay [24]. Here, ABCB1 is linked to lymphoma.