Structures of cadinane- and guaiane-type sesquiterpenoids from Enterospermum madagascariensis (Baill.) Homolle.

Three new cadinane- and guaiane-type sesquiterpenoids, 2-hydroxy-10-epi-zonarene 1, 2, 15-dihydroxycalamenene 2 and guaia-4, 6-dien-3-one 3, were isolated from the wood of Enterospermum madagascariensis (Rubiaceae) grown in Madagascar. Their structures were established from concerted application of 2D NMR techniques including gs-COSY, gs-HMQC, gs-HMBC and NOESY.

(1)H and (13)C chemical shifts for 2-aryl and 2-N-arylamino benzothiazole derivatives.

The (1)H and (13)C NMR resonances for forty-three 2-aryl and 2-N-arylamino benzothiazole derivatives were completely assigned using a concerted application of one- and two-dimensional experiments (DEPT, gs-COSY, gs-HMQC and gs-HMBC).