Bufadienolides (from lat. Bufo - toad) - a group of steroid compounds containing an α-pyrone fragment at position 17 of the steroid skeleton, unsaturated derivatives of bufanolide [1] . Bufadienolides are biologically active substances of plant and animal origin with cardiotonic and cardiotoxic effects.
Glycosides of hydroxy-substituted bufadienolides are found in plants of the lily and buttercup families , in free form or in the form of glycosides - in the protective secretion of the skin glands of some species of toads (for example, bufotalin in the secret of the common toad Bufo bufo ).
The cardiotonic and, in high doses, cardiotoxic effects of bufadienolides are due to inhibition of Na + , K + ATPases (adenosine triphosphatases) in vertebrates, which leads to suppression of the membrane transport of sodium and potassium ions through the membranes of heart muscle cells [2] .
In its physiological effect, bufodienolides are similar to cardenolides - steroid compounds of similar structure, in which at position 17 there is a structurally similar unsaturated five-membered lactone cycle; glycosides of both groups of compounds are referred to as cardiac glycosides .
Notes
- ↑ Definitive Rules for Nomenclature of Steroids, IUPAC, 1971, page 298 (unreachable link) . Date of treatment March 10, 2015. Archived March 4, 2016.
- ↑ Flier, J .; Edwards, MW; Daly, JW; Myers, CW Widespread occurrence in frogs and toads of skin compounds interacting with the ouabain site of Na +, K + -ATPase (Eng.) // Science: journal. - 1980 .-- 5 February ( vol. 208 , no. 4443 ). - P. 503-505 . - ISSN 1095-9203 0036-8075, 1095-9203 . - DOI : 10.1126 / science.6245447 . - PMID 6245447 .