Cinchonidine (1),
cinchonine (2), quinine (3), and noscapine (narcotine, 4) are the alkaloids which are used for the treatment of biological diseases like malaria, analgesic pain, anti-inflammatory, cancer, and stroke treatment [5].
Together they isolated a number of alkaloids such as brucine,
cinchonine, quinine, and strychnine.
Several synthetic compounds, such as verapamil (Tsuruo et al., 1981; Salmon et al., 1991), PSC833 (Boesch et al., 1991; Twentyman and Bleehen, 1991), GF120918 (Hyafil et al., 1993), LY335979 (Dantzig et al., 2001), etc., and natural products, such as the quinone alkaloids
cinchonine (Genne et al., 1992), quinine (Solary et al., 1990), etc., are known to at least partially overcome P-gp mediated MDR.
A number of various other chemicals can also be synthesised from cinchona, and these include
cinchonine, cinchonidine and quinidine.