Alkaloids are used as medications, for local anesthesia, analgesic morphine for head ache etc. They are also used against cancer and hyper tension.
Coca type alkaloids are used by south americans as drugs. Acontine and Tubocurarine, were used for poisoning arrows. Pyrrolidine is found in the leaves of tobacco and carrot. These are used to activate ketones and aldehydes. Pyrrolidine is used for systhesizing more complex compounds too.
Piperidine is used as a Solvent and as a Base. Industrial application of piperidine is for the production of dipiperidinyl dithiuram tetrasulfide, which is used as a rubber vulcanization accelerator.