1.0 2010-04-08 22:06:32 UTC 2025-11-18 22:58:17 UTC FDB005121 Isoprene Isoprene, also known as 2-methyl-1,3-butadiene, belongs to the class of organic compounds known as branched unsaturated hydrocarbons. These are hydrocarbons that contains one or more unsaturated carbon atoms, and an aliphatic branch. It is a common organic compound with the formula CH2=C(CH3)‚àíCH=CH2. In its pure form it is a colorless volatile liquid. It is produced by many plants and animals (including humans) and its polymers are the main component of natural rubber. C. G. Williams named the compound in 1860 after obtaining it from thermal decomposition (pyrolysis) of natural rubber. He correctly deduced the empirical formula C5H8 (https://doi.org/10.1098/rspl.1859.0101). Isoprene is produced and emitted by many species of trees (major producers are oaks, poplars, eucalyptus, and some legumes). Isoprene is made through the mevalonic acid pathway in the cytosol and also, in eubacteria, green algae and the plastids of superior plants, through the methyl-erythritol 4-phosphate pathway (MEP pathway, also called the non-mevalonate pathway). Isoprene has been detected, but not quantified, in a few different foods, such as carrots, sweet oranges, and wild carrots. β-methylbivinyl C5H8 68.117 68.062600256 2-methylbuta-1,3-diene isoprene 78-79-5 CC(=C)C=C InChI=1S/C5H8/c1-4-5(2)3/h4H,1-2H2,3H3 RRHGJUQNOFWUDK-UHFFFAOYSA-N belongs to the class of organic compounds known as branched unsaturated hydrocarbons. These are hydrocarbons that contains one or more unsaturated carbon atoms, and an aliphatic branch. Branched unsaturated hydrocarbons Organic compounds Hydrocarbons Unsaturated hydrocarbons Branched unsaturated hydrocarbons Aliphatic acyclic compounds Alkadienes Unsaturated aliphatic hydrocarbons Acyclic olefin Aliphatic acyclic compound Alkadiene Branched unsaturated hydrocarbon Olefin Unsaturated aliphatic hydrocarbon Hemiterpenoids (C5) a carbohydrate alkadiene hemiterpene liquid logp 2.22 ALOGPS logs -1.58 ALOGPS solubility 1.80e+00 g/l ALOGPS melting_point -145.9 oC logp 1.88 ChemAxon iupac 2-methylbuta-1,3-diene ChemAxon average_mass 68.117 ChemAxon mono_mass 68.062600256 ChemAxon smiles CC(=C)C=C ChemAxon formula C5H8 ChemAxon inchi InChI=1S/C5H8/c1-4-5(2)3/h4H,1-2H2,3H3 ChemAxon inchikey RRHGJUQNOFWUDK-UHFFFAOYSA-N ChemAxon polar_surface_area 0 ChemAxon refractivity 24.58 ChemAxon polarizability 8.58 ChemAxon rotatable_bond_count 1 ChemAxon acceptor_count 0 ChemAxon donor_count 0 ChemAxon physiological_charge 0 ChemAxon formal_charge 0 ChemAxon Specdb::EiMs 490 Specdb::CMs 102862 Specdb::CMs 123682 Specdb::NmrOneD 2641 Specdb::NmrOneD 3328 Specdb::MsMs 92421 Specdb::MsMs 92422 Specdb::MsMs 92423 Specdb::MsMs 156030 Specdb::MsMs 156031 Specdb::MsMs 156032 Specdb::MsMs 3440773 Specdb::MsMs 3440774 Specdb::MsMs 3440775 Specdb::MsMs 3441538 Specdb::MsMs 3441539 Specdb::MsMs 3441540 35194 Carrot Type 1 specific Daucus carota ssp. sativus 79200 Sweet orange Type 1 specific Citrus sinensis 2711 Wild carrot Type 1 specific Daucus carota 4039