[{"from": "human", "value": "Describe this molecule. [C][C][/C][=C][/C][=C][/C][=C][/C][=O]"}, {"from": "gpt", "value": "The molecule is a nona-2,4,6-trienal in which all three double bonds adopt trans-configurations. It has a role as a flavouring agent, an animal metabolite and a pheromone."}]