title: Seasonal variation on the contents of coumarin and kaurane-type diterpenes in Mikania laevigata and M. glomerata leaves under different shade levels.
abstract: Coumarin (1) and kaurane-type diterpenes are considered the bioactive constituents of Mikania glomerata and M. laevigata, used in Brazil to treat respiratory affective disorders. The seasonal variation of 1, ortho-coumaric acid (2), benzoylgrandifloric acid (3), cinnamoylgrandifloric acid (4), and kaurenoic acid (5) in leaves of both species, cultivated in full sunlight and under shade levels of 40 and 80%, was quantified by HPLC. Compound 2 was detected solely in M. laevigata in concentrations below the limit of quantification. Coumarin was not found in M. glomerata, whereas its concentration reached 0.94±0.24% (w/w) in M. laevigata farmed in summer under 80% shading. Both Mikania species produced higher amounts of kaurane diterpenes when cultivated in plenty of sunlight. Hence, maximum contents of 1 are reached in M. laevigata cultivated under high shading, but with reduced concentrations of 3-5. Conversely, M. glomerata should be cultivated under full sunlight and harvested in winter for highest concentrations of kaurane-type diterpenes.
authors: Department of Pharmaceutical Products, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos 6627, 31270-901, Belo Horizonte, MG, Brazil.
authors: Suzan Kelly V
authors: SK
authors: Bertolucci
authors: Ana Bárbara D
authors: AB
authors: Pereira
authors: José Eduardo B P
authors: JE
authors: Pinto
authors: Alaíde B
authors: AB
authors: Oliveira
authors: Fernão C
authors: FC
authors: Braga
mesh_terms: D003374:Coumarins / Q000032:analysis*; D045786:Diterpenes, Kaurane / Q000032:analysis*; D035742:Mikania / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D012621:Seasons; D013472:Sunlight
chemical_list: D003374:Coumarins; D045786:Diterpenes, Kaurane; C030123:coumarin