كومارينات: خصائص وأنواع

Coumarins

• Coumarins are organic chemical compounds belonging to the benzopyrone chemical class.
• They are colorless crystalline substances found naturally in many plants.
• Coumarins are derivatives of benzo-alpha-pyrone, which is a lactone of O-hydroxycinnamic acid.
• They exhibit a characteristic odor and fluorescence in ammoniacal solutions under ultraviolet light, appearing blue, blue-green, or violet.
• Coumarins are classified based on the substitutions in the benzene and pyrone rings. Subtypes include: simple coumarins, furanocoumarins, pyranocoumarins, and bis- and tri-coumarins.
• Simple coumarins contain hydroxyl, alkoxy, or alkyl substituents in both the benzene and pyrone rings.
• Furanocoumarins have a furan ring attached to the coumarin skeleton. They are often linear or angular in shape and may have substitutes on the benzene ring or pyrone ring, including dihydrofuranocoumarins.
• Pyranocoumarins have a pyran ring incorporated into the coumarin skeleton. They can have linear or angular substituents on the benzene and pyrone rings.
• Bis- and tri-coumarins have two or three coumarin units linked together. They often display anticoagulant properties.
• Examples of plants containing coumarins include Khella (Ammi visnaga), found in the Apiaceae (Umbelliferae) family. The whole herb is used.
• Important constituents of Khella include khellin (furanochromone) and visnadin.
• Uses of coumarin-containing drugs include treatment of coronary and myocardial circulation, acting as mild ionotropic agents, antispasmodic effects on smooth muscles, treating skin problems, such as vitiligo, psoriasis and patchy hair loss (alopecia areata), and treating asthma, bronchitis, cough and whooping cough.

Umbelliferone (7-hydroxycoumarin)

• It is a yellowish-white crystalline solid with slight solubility in hot water but high solubility in ethanol.
• It naturally occurs in plants belonging to the Apiaceae (Umbelliferae) family, such as carrots and coriander, as well as in Asteraceae plants.
• Umbelliferone is used as a sunscreen agent as it absorbs ultraviolet light strongly at various wavelengths.

Sweet Clover (Melilotus officinalis)

• Belongs to the Fabaceae family.
• Using this plant can cause bleeding conditions and death in cattle.

Dicoumarol

• Dicoumarol is a natural bicoumarin.
• It has been replaced by its simpler derivative, warfarin, since the mid-1950s.
• Dicoumarol is used as a rodenticide in the chemical industry.