The core skeleton is a six-membered carbocyclic ring, numbered sequentially from C-1 through C-6. The bond between C-1 and C-2 is a double bond, while all other ring bonds are single.

There are five substituents in total, attached to three distinct carbons on the ring:

- At C-1: the carbon bears a methyl group.

- At C-4: two substituents are present:
  1) An isobutyl group, defined as a methylene (-CH2-) directly attached to C-4, which is bonded to a secondary carbon carrying two methyl groups.
  2) A carboxylic acid group.

- At C-6: two substituents are present:
  1) A second carboxylic acid group.
  2) A 2-hydroxyethyl group, defined as a two-carbon saturated chain (-CH2-CH2-) terminating in a hydroxyl group (-OH).