deoxy

Deoxy is a prefix used in chemistry and biology to indicate the absence of oxygen in a molecule or a reduced oxidation state relative to a related compound. The term derives from Greek elements meaning away from and oxygen, and it is used to denote that a compound has been deoxygenated or lacks a specific oxygen atom.

In biology and biochemistry, deoxy often refers to sugars or nucleotides that lack one or more oxygen atoms. The most familiar example is deoxyribose, the sugar in DNA, which lacks the 2' hydroxyl group found in ribose. This structural difference distinguishes deoxyribonucleic acid (DNA) from ribonucleic acid (RNA). Related terms include deoxyribonucleotides and deoxyribonucleosides, such as deoxyadenosine, deoxyguanosine, deoxycytidine, and deoxythymidine. The name reflects the absence of oxygen in the sugar component of DNA.

The prefix also appears in other contexts, such as deoxyhemoglobin, the form of hemoglobin without bound oxygen, which is produced after oxygen release in tissues. In chemistry, deoxy- compounds are those that have been depleted of oxygen or lack a particular oxygen substituent. Examples include 2-deoxy-D-glucose, a glucose analog missing the 2-hydroxyl group and used in research and potential therapeutic contexts. Overall, deoxy denotes a structural or chemical state characterized by the absence of oxygen relative to a reference compound.