Polyene antimycotic

[1] These polyene antimycotics are typically obtained from certain species of Streptomyces bacteria.

However, more detailed studies of polyene molecular properties have challenged this model suggesting that polyenes instead bind and extract ergosterol directly from the cellular membrane thus disrupting the many cellular functions ergosterols perform.

Their structures also often have a D-mycosamine (a type of amino-glycoside) group bonded to the molecule.

[5] The series of conjugated double bonds typically absorbs strongly in the ultraviolet-visible region of the electromagnetic spectrum, often resulting in the polyene antibiotics having a yellow color.

The natural route to synthesis includes polyketide synthase components.

Chemical structure of Amphotericin B . Amphotericin B is an example of a yellow polyene antimycotic agent. Note the alternating double and single bonds in the center and the mycosamine group in the bottom-right corner.
Chemical structure of Nystatin .
Chemical structure of Natamycin , sometimes called pimaricin.