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ABSTRACT: The synthesis of a newangular analog 11 of cyclozonarone was achieved via Diels-Alder reaction between a sesquiterpene-1,3-diene and 1,4-benzoquinone. The cytotoxic activity of ent-cyclozonarone [(+)-10] and the angular (-)-cyclozonarone analog 11 has been determined in three human cancer cell lines and in normal fibroblasts using the sulforhodamine B assay. The analyzed isomers induce cell death in different cancer cell lines by eliciting nuclear condensation and fragmentation, decreasing mitochondrial membrane permeability and increasing caspase-3 activity, all traits indicating apoptosis, with the effects of (+)-10 being stronger than those of 11 in all cases.
Molecules 01/2013; 18(5):5517-30. · 2.39 Impact Factor
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ABSTRACT: The lichen Pseudocyphellaria coriifolia is a species endemic to southern South America. From the lichen thallus, methyl evernate, tenuiorin and three hopane triterpenoids were isolated and identified as the main lichen constituents. Their trypanocidal effects were screened against epimastigotes of Trypanosoma cruzi. The results of the biological test showed that some hopane terpenoids exhibit antiparasitic properties.
Natural product research 11/2012; · 1.01 Impact Factor
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ABSTRACT: Catechols were synthesized from safrole. Nine derivatives were prepared and assessed for antiproliferative effects using different human cell lines. The in vitro growth inhibition assay was based on the sulphorhodamine dye to quantify cell viability. The derivatives 4-allylbenzene-1,2-diol (3), 4 4-[3-(acetyloxy)propyl]-1,2-phenylene diacetate (6) and 4-[3-(acetyloxy)propyl]-5-nitro-1,2-phenylene diacetate (10) showed higher cytotoxicity than the parent compound 2 in tests performed on two breast cancer cell lines (MCF-7 and MDA-MB-231). The IC₅₀ values of 40.2 ± 6.9 μM, 5.9 ± 0.8 μM and 33.8 ± 4.9 μM, respectively, were obtained without toxicity towards dermal human fibroblast (DHF cells).
Molecules 01/2011; 16(6):4632-41. · 2.39 Impact Factor
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ABSTRACT: Two new compounds 2β-acetoxy-15-phenyl-(22,25-acetoxy)-ent-labda-8(17), 13(E)-diene (9) and 2β-hydroxy-15-phenyl-(22,24,26-trimethoxy)-ent-labda-8(17),13(E)-diene (10) have been prepared by an Electrophilic Aromatic Substitution (EAS) reaction between diterpenyl allylic alcohols and 1,4-hydroquinone or 1,3,5-trimethoxybenzene using BF(3).Et(2)O as a catalyst. These compounds, along with a series of natural ent-labdanes 3-8, have been evaluated for their in vitro cytotoxic activities against cultured human cancer cells of PC-3 and DU-145 human prostate cancer, MCF-7 and MDA-MB-231 breast carcinoma and dermal human fibroblasts (DHF). Some compounds displayed inhibition at µM IC(50 )values.
Molecules 01/2010; 15(9):6502-11. · 2.39 Impact Factor
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ABSTRACT: The synthesis and structural determination of two new diterpenylhydroquinones: 2beta-acetoxy-15-phenyl-(22,25-dihydroxy)-ent-labda-8(17),13(E)-diene(1) and 2beta-hydroxy-15-phenyl-(22,25-dihydroxy)-ent-labda-8(17),13(E)-dieneis reported (2). These compounds were obtained by coupling via Electrophilic Aromatic Substitution (EAS) of 1,4-hydroquinone with primary or tertiary allyl alcohol derivatives of the natural ent-labdanes 3 and 4. With this new method, the best results were observed when mixtures of the primary alcohol derivatives 5-6 (26% yield of compound 1) and diol derivatives 9-10 (28% yield of compound 2) were used.
Molecules 02/2009; 14(6):2181-94. · 2.39 Impact Factor
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ABSTRACT: A selective route for the degradation of the unsaturated side chain of ent-labdanes has been devised, giving two useful synthons: 2beta-acetoxy-14,15,17-trinor-ent-labdane-8,13- dione (5) and 2beta-acetoxy-14,15-dinor-ent-labd-8(17)-en-13-one (7), the use of which for the preparation of terpenylquinone derivatives shall be reported elsewhere.
Molecules 02/2007; 12(3):318-27. · 2.39 Impact Factor
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ABSTRACT: A route for the degradation of the side chain of ent-labdane derivatives has been devised, giving the useful synthon 2beta,12-dihydroxy-13,14,15,16,17-pentanor-ent-labdane-8-one (8). The use of this compound in the preparation of terpenylquinone derivatives shall be reported elsewhere. In addition we have synthesized the compound 2beta,12-diacetoxy-8beta,17-epoxy-13,14,15,16-tetranor-ent-labdane (10), which upon catalytic epoxide ring opening in alkaline or acid media gave rise in all cases to the formation of tricyclicc ompounds.
Molecules 02/2007; 12(12):2605-20. · 2.39 Impact Factor
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ABSTRACT: Molecules of the title compound, C12H13NO5, are linked into chains via weak C-H (...)pi( allyl) interactions and these chains are linked into sheets via C-H (...) O contacts; the sheets, in turn, are interconnected via carbonyl-carbonyl and nitro-pi stacking interactions to form a three-dimensional crystal structure.
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ABSTRACT: Molecules in the title crystal structure, C20H24O4, are linked into chains of R-4(4)(8) rings along [010] and these chains are linked into sheets via weak C-H center dot center dot center dot pi(arene) interactions. These sheets are, in turn, linked via weak C-H center dot center dot center dot pi(arene) and C-H center dot center dot center dot O interactions into a three-dimensional network. The ethyl substituent is disordered over two sites with refined occupancies of 0.700 (5) and 0.300 (5).
