Da fração hexânica do extrato metanólico das folhas de Guarea guidonia (Meliaceae), foram isolados os diterpenos: [11S-(1α,2E,6E,10α)]-3,7,11-trimetil-11-(4-metil-pent-3-en-1-i1)biciclo[8.1.0]undeca-2,6-dieno e [1S(1aβ,4aα,7aβ,7bβ)]-decaidro-1,7-dimetil-1-(4-metil-pent-3-en-1-il)-4-metilen-1H-cicloprop[e]azulen-7-ol, já descritos na literatura, além de dois novos isômeros de [1S-(1aβ,4aα,7aβ, 7aβ)]-decaidro-1,7-dimetil-1-(2-hidroxi-4-metil-pent-3-en-1-il)-4metilen-1H-cicloprop[e]azulen-7-ol. No óleo essencial obtido das folhas do mesmo espécimen foram identificados, através da análise dos dados espectroscópicos (RMN ¹³C, RMN ¹H e EM), os sesquiterpenos: eudesma-5,7-dieno, 5α,6α-epoxi-eudesm-7-eno, eudesma-5,7-dien-2α-ol, 5α,6α-epoxi-eudesm-7-en-9-ol e guaia-6-en-10-ol, ainda não descritos na literatura, além de eudesma-4(15), 11(13)-dieno, eudesm-6-em-4α-ol, eudesma-4,11-dieno e 5α,6α,7α,8α-diepoxieudesmano. Diversos extratos vegetais assim como substâncias puras e misturas de composições conhecidas foram testadas com a finalidade de se detectarem substâncias com atividade anticancerígena. Para tal, empregou-se o bioensaio com linhagens mutantes do fungo Saccharomyces cerevisiae, utilizados pelo grupo do Prof. Dr. David Kingston, do Virgínia Tech Institute. Também foi realizado um estudo químico biomonitorado por aquele bioensaio.

From the hexanic extract of the dry leaves of Guarea guidonia (Meliaceae) two new isomers of decahydro-1,7-dimethyl-1-(2-hydroxy-4-methyl-pent-3-en-1-yl)4- methylen-1H-cycloprop[e]azulen-7-ol were isolated together with the known diterpenes [11S-(1α,2E,6E,10α)]-3,7,11-trimethyl-11-(4-methyl-pent-3-en-1yl) bicyclo[8.1.0]undeca-2,6-dien and [1S-(1aβ,4aα,7aβ,7bJ3)]-decahydro-1,7dimethyl- 1-(4-methyl-pent-3-en-1-yl)-4-methylen-1H-cycloprop[e]azulen-7-ol. The essential oil from the leaves of the same plant afforded the sesquiterpenes eudesma-5,7-diene, 5α,6α-epoxy-eudesm-7-ene, eudesma-5,7-dien-2α-ol, 5α,6α-epoxy-eudesm-7-en-9-ol and guaia-6-en-10-ol not previouly described, besides eudesma-4(15),11 (13)-diene, eudesm-6-en-4α-ol, eudesma-4,11-diene and 5α,6α,7α,8α-bisiepoxy-eudesmane. All of these compounds were identified through ¹³C and ¹H NMR spectroscopy as well as MS. Several plant extracts and pure compounds were tested in the search for potential anticancer agents, through the mechanism-based yeast bioassay, utilizing mutants of the yeast Saccharomyces cerevisiae. The screening of those plant materials and a bioassay-guided fractionation of an active extract were both carryed out in the laboratories of Professor David G.I. Kingston at Virginia Tech Institute.