Involved in the biosynthesis of phenolic sesquiterpenes natural products (Ref.2). Sesquiterpene synthase converting (2E,6E)-farnesyl diphosphate (FPP) to (E)-beta-caryophyllene and alpha-humulene (PubMed:20419468, Ref.2). (2E,6E)-farnesyl diphosphate = (-)-(E)-beta-caryophyllene + diphosphate (2E,6E)-farnesyl diphosphate = alpha-humulene + diphosphate Binds 3 Mg(2+) or Mn(2+) ions per subunit. Secondary metabolite biosynthesis; terpenoid biosynthesis. Homodimer. Expressed in peltate glandular trichomes (PubMed:20419468). Present at low levels in flowers, leaves and stems (Ref.3). The Asp-Asp-Xaa-Xaa-Asp/Glu (DDXXD/E) motif is important for the catalytic activity, presumably through binding to Mg(2+). Belongs to the terpene synthase family.