Umbelliferone, also known as 7-hydroxycoumarin, hydrangine, skimmetine, and beta-umbelliferone, is a natural product of the coumarin family.
It absorbs ultraviolet light strongly at several wavelengths. There are some indications that this chemical is antimutagenic, it is used in sunscreens. Umbelliferone has been reported to have antioxidant properties.
It is a yellowish-white crystalline solid that has a slight solubility in hot water, but high solubility in ethanol.
Natural occurrences and name
Umbelliferone’s name is from the umbelliferae family of plants, and the plant family in turn was named for their umbrella-shaped inflorescences, each called an umbel.
Umbelliferone occurs in many familiar plants from the Apiaceae (Umbelliferae) family such as carrot, coriander and garden angelica, as well as in plants from other families, such as the mouse-ear hawkweed (Hieracium pilosella, Asteraceae) or the bigleaf hydrangea (Hydrangea macrophylla, Hydrangeaceae, under the name hydrangine).
Leal, L. K. A. M.; A. A. G. Ferreira; G. A. Bezerra; F. J. A.Matos; G. S. B. Viana (May 2000). “Antinociceptive, anti-inflammatory and bronchodilator activities of Brazilian medicinal plants containing coumarin: a comparative study”. Journal of Ethnopharmacology. 70 (2): 151–159. doi:10.1016/S0378-8741(99)00165-8. ISSN0378-8741. PMID10771205.
Umbelliferone is a phenylpropanoid and as such is synthesized from L-phenylalanine, which in turn is produced via the shikimate pathway. Phenylalanine is lyased into cinnamic acid, followed by hydroxylation by cinnamate 4-hydroxylase to yield 4-coumaric acid. The 4-coumaric acid is again hydroxylated by cinnamate/coumarate 2-hydroxylase to yield 2,4-dihydroxy-cinnamic acid (umbellic acid) followed by a bond rotation of the unsaturated bond adjacent to the carboxylic acid group. Finally an intramolecular attack from the hydroxyl group of C2′ to the carboxylic acid group closes the ring and forms the lactone umbelliferone.
Umbelliferone absorbs strongly at 300, 305 and 325 nm, with log ε values of 3.9, 3.95 and 4.15 respectively, and it fluoresces blue in both ultraviolet and visible light. The powerful absorption at three different wavelengths, coupled with the fact that the energy is dissipated safely as visible light, make umbelliferone a useful sunscreen agent. The absorption changes in alkaline solution, since the phenolic hydroxyl group is deprotonated (pKa = 7.7).
Umbelliferone is a potent inhibitor of type 3 17β-hydroxysteroid dehydrogenase, the primary enzyme responsible for the conversion of 4-androstene-3,17-dione to testosterone, with IC50 of 1.4 μM.
Poirier, Donald (Mar 2003). “Inhibitors of 17 beta-hydroxysteroid dehydrogenases”. Curr Med Chem. 10 (6): 453–477. doi:10.2174/0929867033368222. PMID12570693.
P. Satyanarayana; P. Subrahmanyam; R. Kasai & O. Tanaka (1985). “An apiose-containing coumarin glycoside from gmelina arborea root”. Phytochemistry. 24 (8): 1862–1863. doi:10.1016/S0031-9422(00)82575-3.
Leal, L. K. A. M.; A. A. G. Ferreira; G. A. Bezerra; F. J. A.Matos; G. S. B. Viana (May 2000). “Antinociceptive, anti-inflammatory and bronchodilator activities of Brazilian medicinal plants containing coumarin: a comparative study”. Journal of Ethnopharmacology. 70 (2): 151–159. doi:10.1016/S0378-8741(99)00165-8. ISSN0378-8741. PMID10771205.
Ahluwalia, V. K. (2010-09-30). Intermediates for Organic Synthesis. I. K. International. p. 211. ISBN978-81-88237-33-3.
Poirier, Donald (Mar 2003). “Inhibitors of 17 beta-hydroxysteroid dehydrogenases”. Curr Med Chem. 10 (6): 453–477. doi:10.2174/0929867033368222. PMID12570693.
P. Satyanarayana; P. Subrahmanyam; R. Kasai & O. Tanaka (1985). “An apiose-containing coumarin glycoside from gmelina arborea root”. Phytochemistry. 24 (8): 1862–1863. doi:10.1016/S0031-9422(00)82575-3.
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