label: maytansinoid
label_lc: maytansinoid
description: "Any member of the group of 19-membered lactams that is maytansine or structurally related to it. Maytansinoids have been isolated from members of the higher plant families Celastraceae, Rhamnaceae, and Euphorbiaceae, as well as some mosses and certain Actinomycetes, but the term is used to cover both naturally occurring compounds and their semisynthetic derivatives."