Methyl group

In biochemistry, a methyl group is a hydrophobic alkyl functional group derived from methane (4). It has the formula -3 and is very often abbreviated as -Me in the structure of a molecule. This hydrocarbon unit can be found in many organic compounds.

Methyl groups can be incorporated in organic compounds by an SN2 reaction on iodomethane, or by the reaction of methyl lithium or MeMgCl with a carbon atom that is substituted with a leaving group.

Reactivity
The introduction of methyl groups as new substituents in a compound usually increases the lipophilicity of the compound and reduces its water solubility. It should improve the ease of absorption of the analogue into a biological membrane but will make its release from biological membranes into the aqueous media more difficult. The incorporation of a methyl group can have one of three general effects on the rate of metabolism of an analogue:
 * 1) an increased rate of metabolism due to oxidation of the methyl group
 * 2) an increase in the rate of metabolism due to demethylation by the transfer of the methyl group to another compound, or a reduction of the analogue.