Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids. In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulfur and more rarely other elements such as chlorine, bromine, and phosphorus.

Alkaloids are produced by a large variety of organisms, including bacteria, fungi, plants, and animals, and are part of the group of natural products (also called secondary metabolites). Many alkaloids can be purified from crude extracts by acid-base extraction. Many alkaloids are toxic to other organisms. They often have pharmacological effects and are used as medications, as recreational drugs, or in entheogenic rituals. Examples are the local anesthetic and stimulant cocaine; the psychedelic psilocin; the stimulant caffeine; nicotine; the analgesic morphine; the antibacterial berberine; the anticancer compound vincristine; the antihypertension agent reserpine; the cholinomimeric galatamine; the spasmolysis agent atropine; the vasodilator vincamine; the anti-arhythmia compound quinidine; the anti-asthma therapeutic ephedrine; and the antimalarial drug quinine. Although alkaloids act on a diversity of metabolic systems in humans and other animals, they almost uniformly invoke a bitter taste.

Maaya Sakamoto (坂本 真綾, Sakamoto Maaya^?, born March 31, 1980) is a Japanese singer-songwriter, actress, and voice actress. She made her debut as a voice actress in 1992 as the voice of Chifuru in the anime series Little Twins, but is more well known for her role as Hitomi Kanzaki in the hit anime series The Vision of Escaflowne. She released her debut single Yakusoku wa Iranai, in collaboration with Yoko Kanno under Victor Entertainment on April 24, 1996.

Since her 1996 debut, she is among the more popular voice actresses who have also branched into singing, performing songs in both English and Japanese. As well as being a prolific seiyū, she has also had several successful releases; despite initially only modestly selling, her singles Tune the Rainbow,Loop,Ame ga Furu, and Triangler have all reached the top 10 Oricon singles chart: Triangler in particular charted at #3 and remained charting for 26 weeks. Her albums have had similar success, with Shōnen Alice and Yūnagi Loop both reaching the top 10 Oricon albums chart; and her newest album, You Can't Catch Me, released on January 12, 2011, became her first release to ever reach #1. She held a concert at the Nippon Budokan on March 31, 2010, her thirtieth birthday.