Alkaloids are the chemical compounds which mostly contain nitrogen atoms.these also contains some neutral compounds and etc...
alkaloids are bases and these are used for medicines and also poisons.examples of alkaloids are--1.morphine(used as medicine and to relieve pain
2.quinine(used as medicine and for the treatment of malaria.
3.nicotine(obtained from tobacco plants and to quit smoking)
5.psilocybin(hallucinogenic drug)produced by different species of
hope this helps u.