Midecamycin is a macrolide

Macrolide

The macrolides are a group of drugs whose activity stems from the presence of a macrolide ring, a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered...

antibiotic. Synthesized from Streptomyces mycarofaciens.

Physical Properties

Melting point vary depending on the compound type. It may also vary depending on the source consulted. Example:

For the A₁ type:

The Merck Index reports 155-156 Celsius.
The Japanese Pharmacopoeia reports 153–158 Celsius.

For the A₃ type:

The Merck Index reports 122-125 Celsius.