Chromones pharmacology

Khellin is a natural product closely related to the psoralens in which a chromone ring has been substituted for the cou-marin. The plant material has been used since ancient times as a folk remedy modern pharmacologic work has confirmed the bronchio-dilating and antispasmodic activity of khellin. The synthesis outlined below, it should be noted, is selected from a half-dozen or so reported within the last quarter century. 

In 1962, about 15 chromones were known to occur in plants but by 1975 this number had grown to 55 and has continued to grow. A few chromones have been known for many years to have pharmacological activity and the discovery in 1962 of cromoglycic acid (352)... 

Chromones of therapeutic interest have been reviewed (70FES57) and the pharmacological activity associated with chromanones has been discussed (77HC(3l)345>. 

Aloe is a medicinal plant that has been used since ancient times by cultures in many countries and continents for many of the same applications. Africa is blessed with a wide variety of Aloe spp. each used by the indigenous cultures. Fleshy leaves are the source of two of the main products, gel and latex, with both products showing distinct differences in their chemical composition. Chemical composition of gel consists mainly of water with carbohydrate polymers and a range of other organic and inorganic components. In contrast, the chemical composition of the latex includes many phenolic compounds such as anthraquinones and chromones. The objective of this paper is to review the the botany, chemistiy and pharmacological properties of Aloes from Africa. 

The fruits of Ammi visnapya contain the pharmacologically active chromone (khellin) and pyrano coumarins (visnadin). 

The acid chlorides of several chromone-2-carboxylic acids have been used in the Freidel-Crafts reaction to prepare 2-aroyl-chromones which were pharmacologically active.Decarboxylation of a heterocyclic acid is often a facile reaction but removal of an aldehyde group is unusual. Chromone-3-carboxaldehyde (156) has been decarbonylated by heating with piperidine to give the acrylophenone (157), which cyclized again, with loss of piperidine and one carbon atom. ... 

Immunological Aspects - In the past year, the immunologic approach to asthma therapy has centered around clinical studies employing dlsodlum cromoglycate (III), a chromone derivative whose pharmacology was initially... 

Recently, various amine salts of chromone-2-carboxylic add and its 7-methoxy derivative were prepared for pharmacological testing [180]. 

Derivatives of benzopyran-4-one, commonly known as chromones (I), are an important class of compounds because of their pharmacological significance [1], and one of the derivatives, disodium cromoglycate (II) [2] is at present in clinical use for allergic bronchial asthma- Chromones containing... 

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