[122. Steroidal alkaloids. LXXII. Buxacease (10th communication). Alkaloids of the cycloxobuxidine group isolated from Buxus falearica Willd: N-3-isobutyryl cycloxobuxidine F (baleabuxidine), N-3-isobutyryl cycloxobuxidine H,N-3-benzoyl cycloxobuxidine F, and cycloxobuxoxazine C (baleabuxoxazine)].