Family of sesquiterpenes isolated from the roots of Yingzhao, (Artabotrys uncinatus (L.) Merr.) a traditional Chinese herbal medicine for treatment of malaria. Yingzhaosu A & C contain a peroxy group which is needed for antimalarial activity. Isoln of A: X.-T. Liang et al., Acta Chim. Sin. 37, 215 (1979), C.A. 92, 146954 (1980); of C: L. Zhang et al., J. Chem. Soc. Chem. Commun. 1988, 523. Structure of C: eidem, Sci. China Ser. B 32, 800 (1989). Total synthesis of A: X.-X. Xu et al., Tetrahedron Lett. 32, 5785 (1991); stereocontrolled synthesis: W.-S. Zhou in Newer Trends Essent. Oils. Flavours, Sel. Pap. Int. Symp., K. L. Dhar et al., Eds. (Tata McGraw-Hill, New Delhi, India, 1993) pp 43-50. Enantioselective synthesis of C: X.-X. Xu, H.-Q. Dong, J. Org. Chem. 60, 3039 (1995).
Contains a unique dioxabicyclo[3.3.1]nonane ring system.
Occurs naturally as an enantiomeric mixture of the (3R,6S), (3S,6R) with a predominance of the former.
Antimalarial.