title: Biotransformation of betulinic and betulonic acids by fungi.
abstract: Betulinic acid (1), a triterpenoid found in many plant species, has attracted attention due to its important pharmacological properties, such as anti-cancer and anti-HIV activities. The closely related, betulonic acid (2) also has similar properties. In order to obtain derivatives potentially useful for detailed pharmacological studies, both compounds were submitted to incubations with selected microorganisms. In this work, both were individually metabolized by the fungi Arthrobotrys, Chaetophoma and Dematium, isolated from the bark of Platanus orientalis as well as with Colletotrichum, obtained from corn leaves; such fungal transformations are quite rare in the scientific literature. Biotransformations with Arthrobotrys converted betulonic acid (2) into 3-oxo-7beta-hydroxylup-20(29)-en-28-oic acid (3), 3-oxo-7beta,15alpha-dihydroxylup-20(29)-en-28-oic acid (4) and 3-oxo-7beta,30-dihydroxylup-20(29)-en-28-oic acid (5); Colletotrichum converted betulinic acid (1) into 3-oxo-15alpha-hydroxylup-20(29)-en-28-oic (6) acid whereas betulonic acid (2) was converted into the same product and 3-oxo-7beta,15alpha-dihydroxylup-20(29)-en-28-oic acid (4); Chaetophoma converted betulonic acid (2) into 3-oxo-25-hydroxylup-20(29)-en-28-oic acid (7) and both Chaetophoma and Dematium converted betulinic acid (1) into betulonic acid (2). Those fungi, therefore, are useful for mild, selective oxidations of lupane substrates at positions C-3, C-7, C-15, C-25 and C-30.
authors.affiliation: Universidade Federal do Paraná, Departamento de Química, CP19081, 81531-970 Curitiba-PR, Brazil.
authors.forename: Denise Z L
authors.initials: DZ
authors.lastname: Bastos
authors.forename: Ida C
authors.initials: IC
authors.lastname: Pimentel
authors.forename: Daniel A
authors.initials: DA
authors.lastname: de Jesus
authors.forename: Brás H
authors.initials: BH
authors.lastname: de Oliveira
mesh_terms: D001203:Ascomycota / Q000378:metabolism; D001711:Biotransformation; D020231:Colletotrichum / Q000378:metabolism; D005658:Fungi / Q000378:metabolism*; D015394:Molecular Structure; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D053978:Pentacyclic Triterpenes; D014315:Triterpenes / Q000737:chemistry / Q000378:metabolism*; D000094062:Betulinic Acid
chemical_list: D053978:Pentacyclic Triterpenes; D014315:Triterpenes; C118308:betulonic acid; D009828:Oleanolic Acid; D000094062:Betulinic Acid