Three new labdanes with 8α,15-epoxy ring [methyl 8α,15-epoxylabdan-16β-oate, 8α,15-epoxylabdan-16β-ol and 8α,15-epoxy-16-norlabdan-13β-ol] and five known compounds [8α,15-epoxy-16-norlabdan-13-one, 8α,15-epoxylabdan-16β-oic acid, 3β-(3'',4''-dihydroxy)(E)-cinnamoyloxylup-20(29)-ene, 3-(2',3',4',6'-tetra-O-acetyl-β-D-glucopyranosyloxy)β-sitosterol and 16-acetoxy-8α,15-epoxylabdane] were isolated from toluene and dichloromethane extracts of aerial parts of Eragrostis viscosa. The structures of all the compounds were established based on their spectroscopic data and X-ray diffraction analysis of 8α,15-epoxylabdan-16β-ol. It was also studied the genotoxicity of E. viscosa, particularly compounds 16-acetoxy-8α, 15-epoxylabdane, 8α,15-epoxy-16-norlabdan-13-one and 8α, 15-epoxilabdan-16β-ol, using a cytokinesis-block micronucleus assay and the Ames test to assess mutagenicity. Both assays were negative. Cytotoxicity was also analyzed using an MTT assay, and 8α,15-epoxy-16β-ol was shown to be the most cytotoxic of the compounds tested. E. viscosa extracts were also tested to determine their antioxidant capacities, peroxide values and total phenolic contents.

Three new neo-clerodanes, antiscorbuticane A, antiscorbuticane B and antiscorbuticane C, and known compounds glutinol, friedelin, 5,7-dihydroxyflavanone (pinocembrin), 5-hydroxy-3,6,7,4'-tetramethoxyflavone, 5-hydroxy-3,6,7,3',4'-pentamethoxyflavone (artemetin), 5,4'-dihydroxy-3,6,7,3'-tetramethoxyflavone (penduletin) and 5,3',4'-trihydroxy-3,6,7-trimethoxyflavone (chrysosplenol D), were isolated from the methanol extract of Tinnea antiscorbutica. Antiscorbuticane B exhibited no mutagenic activity at doses of up to 250 µg per plate (Ames test) and did not induce micronucleus formation in the V79 cell line at doses of up to 100 µg /mL.

Three new labdanes with 8 alpha,15-epoxy ring {[}methyl 8 alpha,15-epoxylabdan-16 beta-oate, 8 alpha,15-epoxylabdan-16 beta-ol and 8 alpha,15-epoxy-16-norlabdan-13 beta-ol] and five known compounds {[}8 alpha,15-epoxy-16-norlabdan-13-one, 8 alpha,15-epoxylabdan-16 beta-oic acid, 3 beta-(3 `',4 `'-dihydroxy)-(E)-cinnamoyloxylup-20(29)-ene, 3-(2',3' 4',6'-tetra-O-acetyl-beta-D-glucopyranosyloxy)-beta-sitosterol and 16-acetoxy-8 alpha,15-epoxylabdane] were isolated from toluene and dichloromethane extracts of aerial parts of Eragrostis viscosa. The structures of all the compounds were established based on their spectroscopic data and X-ray diffraction analysis of 8 alpha,15-epoxylabdan-16 beta-ol. It was also studied the genotoxicity of E. viscosa, particularly compounds 16-acetoxy-8 alpha,15-epoxylabdane, 8 alpha,15-epoxy-16-norlabdan-13-one and 8 alpha,15-epoxilabdan-16 beta-ol, using a cytokinesis-block micronucleus assay and the Ames test to assess mutagenicity. Both assays were negative. Cytotoxicity was also analyzed using an MTT assay, and 8 alpha,15-epoxy-16 beta-ol was shown to be the most cytotoxic of the compounds tested. E. viscosa extracts were also tested to determine their antioxidant capacities, peroxide values and total phenolic contents.}}