CHAPTER ONE
1.1 INTRODUCTIONAlkaloids are a class of organic compounds that typically contain nitrogen and have complex ring structures. They occur naturally in seed bearing plants and are found in berries, bark, fruits, roots and leaves. That is, they are derived from plants. Often, they are bases that have some physiological effects.Many of the earliest isolated pure compounds with biological activity. This was due to the ease of isolation. The nitrogen generally makes the compound basic and the compound exists in the plant as a salt. This, alkaloids are often extracted with water or mild acid and then recovered as crystalline material by treatment with base. Prior to approximately 300 years ago malaria was the scourage of Europe, likely having been introduced though the middle East. Malaria is caused by protozoa of the genus plasmodium, contained as spores in the gut of the anopheles mosquitoes, which then spread the spores to humans when they bites. As the Spanish and Portuguese explores began to colonize. South America they discovered a cure for Malaria known to the native Indians. This was the bark of the cinchona tress. The use of cinchona bark to treat Malaria was first reported in Europe in 1633, and the first bark reached Rome about 12 years later teas made from the bark cures people suffering from Malaria, one of the major scourges in Europe at the time and the bark became known as Jesuits bark. Because of the philosophical differences between protestants and catholic, many protestants refused to be treated with the bark. One of the most prominent protestants of the time, Olive
Isolate originally from cinchona Succirubra, quinine is one of 31 alkaloids with related structure, and the principal ant malaria compound, in the plant. Alkaloids have been defined in various ways, but one definition come fairly close to actuality. An alkaloid is plant – derived compounds that is toxic or physiologically active, contain nitrogen in a heterocyclic ring, and is basic, has a complex structure, and is of limited distribution in the plant kingdom,. Malaria is still a major problem throughout the world, and although synthetic antimalaria drugs largely supplanted quinine as the treatment for malaria during world warII, quinine is often once again the drug of choice as strain of malarial have become resistant to the synthetic drugs. However, the search for other antimalaria drugs from natural sources has also continued.One of the most promising new drugs is qinghaosu, isolated from Artemisia annua.
Among the most famous of the alkaloids are the slanaceae or tropane alkaloids. Plants containing these alkaloids have been used throughout recorded history as poisons, but many of the alkaloids do have valuable pharmaceutical properties.
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