Coumarin derivatives

Coumarin derivatives are derivatives of coumarin and are considered phenylpropanoids.^[1] Among the most important derivatives are the 4-hydroxycoumarins, which exhibit anticoagulant properties, a characteristic not present for coumarin itself.

Some naturally occurring coumarin derivatives include umbelliferone (7-hydroxycoumarin), aesculetin (6,7-dihydroxycoumarin), herniarin (7-methoxycoumarin), psoralen and imperatorin.

4-Phenylcoumarin is the backbone of the neoflavones, a type of neoflavonoids.

Coumarin pyrazole hybrids have been synthesized from hydrazones, carbazones and thiocarbazones via Vilsmeier Haack formylation reaction.

Compounds derived from coumarin are also called coumarins or coumarinoids; this family includes:

• brodifacoum^[2][3]
• bromadiolone^[4]
• difenacoum^[5]
• auraptene
• ensaculin
• phenprocoumon (Marcoumar)
• PSB-SB-487
• PSB-SB-1202
• scopoletin can be isolated from the bark of Shorea pinanga^[6]
• warfarin (Coumadin)

Coumarin is transformed into the natural anticoagulant dicoumarol by a number of species of fungi.^[7] This occurs as the result of the production of 4-hydroxycoumarin, then further (in the presence of naturally occurring formaldehyde) into the actual anticoagulant dicoumarol, a fermentation product and mycotoxin. Dicoumarol was responsible for the bleeding disease known historically as "sweet clover disease" in cattle eating moldy sweet clover silage.^[7][8] In basic research, preliminary evidence exists for coumarin having various biological activities, including anti-inflammatory, anti-tumor, antibacterial, and antifungal properties, among others.^[7]

Warfarin – a coumarin – with brand name, Coumadin, is a prescription drug used as an anticoagulant to inhibit formation of blood clots, and so is a therapy for deep vein thrombosis and pulmonary embolism.^[9][10][11] It may be used to prevent recurrent blood clot formation from atrial fibrillation, thrombotic stroke, and transient ischemic attacks.^[11]

Coumarins have shown some evidence of biological activity and have limited approval for few medical uses as pharmaceuticals, such as in the treatment of lymphedema.^[9][12] Both coumarin and 1,3-indandione derivatives produce a uricosuric effect, presumably by interfering with the renal tubular reabsorption of urate.^[13]

Coumarin dyes are extensively used as gain media in blue-green tunable organic dye lasers.^[14][15][16] Among the various coumarin laser dyes are coumarins 480, 490, 504, 521, 504T, and 521T.^[16] Coumarin tetramethyl laser dyes offer wide tunability and high laser gain,^[17][18] and they are also used as active medium in coherent OLED emitters.^{[19][14][15][16]} and as a sensitizer in older photovoltaic technologies.^[20]