4.1.4.3B Pyran-based Constituents: They are derived from six-membered heterocylic ring ‘pyran’, namely:
(a) Dicoumarol (Syn: Dicoumarin: Dufalone; Melitoxin;): It was originally isolated from sweet clover (Improperly cured Mililotus hay).
(b) Umbelliferone (Syn: Hydrangin; Skimmetin;): It is present in many plants and obtained by the distillation of resins belonging to the natural order Umbelliferae. It is the aglucon of skimmin.
(c) Meconic Acid (Syn: Oxychelidonic acid): It is obtained from opium i.e., Papever\ somniferum which contains 4 to 6% of meconic acid.
(d) Coumestrol: An estrogenic factor occuring naturally in forage crops, especially in ladino clover (Trifolium repens L.), strawberry clover (T. fragiferum) and alfalfa (Medicago sativa L.).
REFERENCES
Ashutosh Kar (2003), Pharmacognosy and Pharmaco biotechnology, 2nd Edition
‘Handbook of Medicinal Herbs’ (2001), J.A. Duke, CRC-Press, London, 1st Edn.
William Charles Evans (2002), Trease and Evans Pharmacognosy 15th Edition by: Trease, Bailliere Tindall; Evans.
Ramstad (1956), E., ‘Modern Pharmacognosy’, McGraw Hill, London.
