Mycomycin, a naturally occurring antibiotic produced by the fungus Nocardia acidophilus, has the molecular formula C13H10O2 and the systematic name 3,5,7,8 -tridecatetraene- 10,12 diynoic acid. Draw the structure of mycomycin.
The Correct Answer and Explanation is:
To draw the structure of mycomycin, you need to account for its molecular formula C13H10O2C_{13}H_{10}O_2C13H10O2 and its systematic name “3,4,7,8-tridecatetraene-10,12-diynoic acid.”
Step 1: Identify the basic components
- Aromatic rings: The name “tridecatetraene” suggests the presence of conjugated double bonds (tetraene), and this is often indicative of an aromatic ring structure, which is likely a benzene ring (C6H5).
- Conjugated system: The name “tridecatetraene” also tells you there are alternating double bonds (i.e., a conjugated system of 4 double bonds). This is typically found in a polyene chain.
- Diynoic acid: The presence of “diynoic acid” suggests two triple bonds (C≡C) are located at positions 10 and 12 of the molecule, along with a carboxylic acid group (-COOH) at the end.
Step 2: Drawing the structure
- Benzene ring: Start with a six-membered carbon ring with alternating double bonds (C6H5).
- Polyene chain: Attach a polyene chain to the benzene ring. The chain should be 7 carbon atoms long, with alternating single and double bonds. The positions 10 and 12 should be triple bonds.
- Carboxylic acid group: Attach a carboxyl group (-COOH) to the last carbon of the polyene chain.
- Positioning of functional groups: The carboxyl group is at the 10th position, and the triple bonds occur at positions 10 and 12. This conjugated system is consistent with mycomycin’s structure.
Step 3: The structure
The final structure of mycomycin would look like this:
- A benzene ring (C6H5) attached to a long chain (C13).
- The chain consists of alternating single and double bonds, with two triple bonds and a carboxyl group (-COOH) at the terminal end.
Explanation of the structure:
The alternating double bonds in the polyene chain create a conjugated system, which is important for the molecule’s chemical reactivity. The carboxyl group at the end of the molecule contributes to its acidic nature and may play a role in its biological activity as an antibiotic. The conjugated system and triple bonds contribute to the molecule’s overall stability and its ability to interact with bacterial targets.
