Lourdes Castañeda

In this communication we describe a novel acid-cleavable linker strategy for antibody–drug conjugation. Functional disulfide bridging of the single interchain disulfide bond of a trastuzumab Fab fragment yields a homogeneous antibody–drug conjugate bearing a thiomaleamic acid linker. This linker is stable at physiological pH and temperature, but quantitatively cleaves at lysosomal pH to release the drug payload.

In this review, the natural source, structure, biological activities and the synthesis of labdanes diterpenes with highly functionalized B rings, described to date are shown. The structures for these compounds have been classified taking into account the number of oxygenated positions of the B ring. In this manner the classification has 7 groups of deoxygenated labdanes, 6 of trioxygenated and one group of the tetraoxygenated ones.

A new access to tricyclic diterpenes of podocarpane ­skeleton has been opened, in excellent overall yields, and an efficient synthesis of (+)-nimbiol from sclareol has been achieved.