abstract |
Compound of formula (I): **(See formula)** in which R is straight or branched chain C3-C20 alkyl, straight or branched chain C2-C20 alkenyl, C2-C20 alkynyl, C3-C20 cycloalkyl, C6-C10 aryl, C3-C20 heterocyclyl, or C5-C10 heteroaryl, or a salt thereof. |