Neolignans and sesquiterpenes from leaves and embryogenic cultures of Ocotea Catharinensis (Lauraceae)

Abstract

Foram isoladas de extratos de folhas de Ocotea catharinensis Mez (Lauraceae) quatorze neolignanas sendo nove benzofurânicas (incluindo três novas substâncias 1e, 2f e 4b), uma secobenzofurânica inédita (3b), duas biciclo[3.2.1]octânicas (incluindo a nova 5c), dois novos dímeros biciclo[3.2.1]octânicos (7a e 7b) e ainda dois sesquiterpenos (incluindo o novo humulanol 9). Nos embriões somáticos de O. catharinensis foram identificadas sete neolignanas incluindo uma nova neolignana biciclo[3.2.1]octânica (4a).The extracts from leaves of Ocotea catharinensis Mez (Lauraceae) were found to contain fourteen neolignans and two sesquiterpenes: nine benzofuran types (including three new compounds 1e, 2f and 4b), one new seco-benzofuran type (3b), two bicyclo[3.2.1]octane types (including the new compound 5c), two new dimers of bicyclo[3.2.1]octane type (7a and 7b) and two sesquiterpenes (including a new humulanol 9). In addition, seven neolignans were also showed to occur in somatic embryos of O. catharinensis including one new bicyclo[3.2.1]octane type (4a). Keywords:Ocotea catharinensis, benzofuran neolignans, bicyclo[3.2.1]octane neolignans, humulane sesquiterpene, somatic embryos IntroductionOcotea catharinensis (Lauraceae) is a woody plant species found in southern Atlantic forest in Brazil, which produces excellent quality of timber. The extensive logging over the past thirty years associated with difficulties for propagation has led its natural population to be significant decrease. Since O. catharinensis has been included as endangered species, a somatic embryogenic system was developed aiming to a massive propagation. 1,2The Ocotea has been one of the most phytochemically investigated Lauraceous genus and their major secondary compounds were showed to be phenylpropanoidderived including several sub-classes of neolignans. 3Previous phytochemical studies carried out in leaves of O. catharinensis collected at Horto Florestal (Serra da Cantareira), São Paulo State, Brazil, reported the occurrence of benzofuran (1b, 1c, 1d, 2b, 2c, 2d, 2e and 2h) and bicyclo[3.2.1]octane (5a, 5b and 5d) neolignans. 4Representatives of both sub-classes of neolignans have also been previously isolated from barks and woods of a specimen collected in São Paulo State, 5,6 and also from wood and leaves of O. porosa ("imbuia") collected in Rio Grande do Sul State, southern Brazil. [7][8][9] This work describes the isolation and characterization of major secondary compounds from leaves collected at Vale do Itajaí, Santa Catarina State, Brazil and from embryogenic cultures developed from the same plant source. The extracts from leaves afforded seven new neolignans 1e, 2f, 3b, 4b, 5c, 7a, 7b, besides seven previously reported ones 1a, 6,10 Results and DiscussionThe defatted fraction of hexane extracts from O. catharinensis leaves and from O. catharinensis somatic embryos were submitted to flash chromatography followed by prep. TLC and/or circular chromatography (Chromatotron®). This procedure yielded nine new compounds (1e, 2f, 3b, 4a, 4b, 5c, ...

Antiherpetic activity of a flavonoid fraction from Ocotea notata leaves

“…It is widespread over the Brazilian Atlantic coast and grows mainly in sandy coastal plains, where it is used as timber-tree. The chemodiversity of Ocotea genus is well recognized and several alkaloids, terpenes, lignans and neolignans have been reported (Dias et al, 2003;Zanin & Lordello, 2007;Barbosa-Filho et al, 2008;Funasaki et al, 2009;Cuca et al, 2009). Nevertheless, only a small number of papers describe the presence of flavonoids in this genus (David et al, 1994;Garcez et al, 1995Garcez et al, , 2005.…”

Neolignans and Other Metabolites from Ocotea cymosa from the Madagascar Rain Forest and Their Biological Activities

“…Plant species from the genus Ocotea are rich sources of neolignans including the bicyclo[3.2.1]octanoid neolignans ocobullenone ( 10b ), 5 iso-ocobullenone, 6 sibyllenone ( 7b ), 7 ocophyllals A and B, 8 and virolongin-type 9 and benzofuran neolignans. 10 Various biological activities such as insecticidal, antibacterial, antitumor, and antiviral have been reported for the lignans. 11 Aporphine alkaloids 12–15 and flavonoids 16 have also been isolated from plants of this genus.…”

Biossíntese de neolignanas em Ocotea catharinensis e filogenia molecular de Lauraceae

“…..............31 Figura 1.5. Metabólitos secundários das cascas, madeira e folhas de Ocotea catharinensis (Ishige et al, 1991 (Funasaki, et al, 2009 ............................................104 Figura 4.1. Neolignanas identificadas nos embriões de O. catharinensis.................................................105 .............................................................................................................................................111 Figura 4.3.…”

“…Dentro de Lauraceae, o gênero Ocotea é um dos mais estudados fitoquimicamente. Este gênero produz uma variedade de metabólitos secundários, sendo a maioria deles derivados de fenilpropanóides, incluindo várias subclasses de lignanas e neolignanas (Dasilva et al, 1989;David et al, 1994a;David et al, 1994b;Decarvalho et al, 1988;Dias et al, 1986;Felicio et al, 1986;Franca et al, 1975;Gomes et al, 1983;Haraguchi et al, 1983;Ishige et al, 1991;Marques et al, 1992;Romoff et al, 1984;Smit, 2004 (Haraguchi et al, 1983;Ishige et al, 1991;Lordello e Yoshida, 1997;Funasaki et al, 2009). (Haraguchi et al, 1983) 1a A partir do perfil químico desta espécie, que mostra o acúmulo de neolignanas, foi proposto um estudo biossintético desta classe de compostos em culturas embriogênicas de O. catharinensis.…”

“…As espécies O. catharinensis e O. macrophylla produzem neolignanas dihidrobenzofurânicas (Haraguchi et al, 1983;Lordello et al, 1997;Coy-Barrera et al, 2009;Funasaki et al, 2009; Coy-Barrera e Cuca-Suaréz, 2011) e, portanto, estes dados dão suporte para a proposta de que estas, seriam formadas pelo acoplamento oxidativo cruzado entre unidades de propenil-e alilfenóis, mediados por tais proteínas. evoluem rapidamente, por isso são muito usadas para discriminar espécies relacionadas ou até mesmo variedades de uma mesma espécie (White et al, 1990).…”