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