[{"from": "human", "value": "Provide a description of this molecule. [C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C][C]"}, {"from": "gpt", "value": "The molecule is an alkane that has 21 carbons and a straight-chain structure. It has been isolated from plants like Periploca laevigata and Carthamus tinctorius. It has a role as a pheromone, a plant metabolite and a volatile oil component."}]