(2E,6E)-farnesyl diphosphate <=> (+)-(R)-germacrene A + diphosphate
(2e,6e)-farnesyl diphosphate <=> (+)-(r)-germacrene a + diphosphate
(2E,6E)-farnesyl diphosphate <=> (+)-(R)-germacrene A + diphosphate
(2e,6e)-farnesyl diphosphate <=> (+)-(r)-germacrene a + diphosphate