meso- definition

<prefix>

1. A combining form or prefix meaning middle, mean, intermediacy.

2. <chemistry> Denoting a type of hydrocarbons which are regarded as methenyl derivatives. Also used adjectively.

3. Optically inactive due to compensating optical activity at two or more asymmetric centers, often due to a plane of symmetry within the molecular structure; as, meso-tartaric acid.

4. Attached to a carbon atom located between two hereoatoms in a heterocyclic ring.

5. A mesentery, mesentery-like structure.

Origin: Gr. mesos in the middle.

(05 Feb 2009)