Alkaloids (Second Edition)Chemistry, Biology, Ecology, and Applications
2015, Pages 1–97
Chapter 1 – Definition, typology, and occurrence of alkaloids
- Helsinki, Finland
- Available online 25 April 2015
Abstract
Alkaloids
are a group of molecules with a relatively large occurrence in nature
around the globe. They are very diverse chemicals and biomolecules, but
they are all secondary compounds and are derived from amino acids or
from the transamination process. Alkaloids are classified according to
the amino acids that provide their nitrogen atom and part of their
skeleton. Similar alkaloids can have quite different biosynthetic
pathways and different bioimpacts. Alkaloids are derived from l-lysine, l-ornithine, l-tyrosine, l-tryptophan, l-histidine, l-phenylalanine,
nicotinic acid, anthranilic acid, acetate, or amination and
transamination reactions. The terpenoid, steroid, and purine alkaloids
are also important. Millions of people around the globe use purine
alkaloids every day whether starting the day with a cup of coffee or
drinking a cup of tea in the afternoon. Alkaloids also occur in the
animal kingdom. Unlike plants, the source of these molecules in an
animal’s body can be endogenous or exogenous. Alkaloids are molecules
participating in both producer and consumer chains in nature. They are
vital in feeding and enjoy activation, aggression, and defense of
various species. Homo sapiens is one of them.
Keywords
- Alkaloid;
- alkaloid derivation;
- alkaloid occurrence;
- heterocycles;
- molecular precursors;
- protoalkaloids;
- pseudoalkaloids;
- true alkaloids
Copyright © 2015 Tadeusz Aniszewski. Published by Elsevier B.V. All rights reserved.
