Alkaloids from Plants with Antimalarial Activity: A Review of Recent Studies

Abstract

Malaria is one of the major health problems in developing countries. The disease kills a large number of people every year and also affects financial status of many countries. Resistance of the plasmodium parasite, the causative agent, to the existing drugs, including chloroquine, mefloquine, and artemisinin based combination therapy (ACT), is a serious global issue in malaria treatment and control. This warrants an urgent quest for novel compounds, particularly from natural sources such as medicinal plants. Alkaloids have over the years been recognized as important phytoconstituents with interesting biological properties. In fact, the first successful antimalarial drug was quinine, an alkaloid, which was extracted from Cinchona tree. In the present review work, the alkaloids isolated and reported recently (2013 till 2019) to possess antimalarial activity are presented. Several classes of alkaloids, including terpenoidal, indole, bisindole, quinolone, and isoquinoline alkaloids, were identified with a promising antimalarial activity. It is hoped that the reports of the review work will spur further research into the structural modification and/or development of the interesting compounds as novel antimalarial drugs.

Figure 1

Structures of some antimalarial drugs.

Figure 2

Structures of terpenoidal and steroidal alkaloids.

Figure 3

Structures of indole and related alkaloids with promising antiplasmodial activity.

Figure 4

Structures of isoquinoline alkaloids.

Figure 5

Structures of bisbenzylisoquinoline (40, 41, and 44) and hasubanane (42 and 43) alkaloids.

Figure 6

Structures of naphthylisoquinoline (45) and dimeric naphthylisoquinoline (46–48-) alkaloids.

Figure 7

Structures of apophine (49, 50, and 52), isoquinoline (51), bisbenzylisoquinoline (53), and morphinandienone (54 and 60) alkaloids.

Figure 8

Structures of protoberberine alkaloids.

Figure 9

Structures of Amaryllidaceae alkaloids.

Figure 10

Chemical structures of cyclopeptides with antiplasmodial activity.

Figure 11

Chemical structures of quinoline (88 and 89), pyridocoumarin (90 and 91), aristolactam (92), acridone (93), and macrocytic (94) alkaloids with antiplasmodial activity.