1.Bioactivity and chemical characterisation of Lophostemon suaveolens - an endemic Australian Aboriginal traditional medicinal plant.
Naz T1, Packer J1,2, Yin P1, Brophy JJ3, Wohlmuth H4,5, Renshaw DE4, Smith J4, Elders YC6, Vemulpad SR1, Jamie JF1. Nat Prod Res. 2016 Mar;30(6):693-6. doi: 10.1080/14786419.2015.1038260. Epub 2015 May 5.
Lophostemon suaveolens is a relatively unexplored endemic medicinal plant of Australia. Extracts of fresh leaves of L. suaveolens obtained from sequential extraction with n-hexane and dichloromethane exhibited antibacterial activity in the disc diffusion and MTT microdilution assays against Streptococcus pyogenes and methicillin sensitive and resistant strains of Staphylococcus aureus (minimum bactericidal concentration < 63 μg/mL). The dichloromethane extract and chromatographic fractions therein inhibited nitric oxide in RAW264.7 murine macrophages (IC50 3.7-11.6 μg/mL) and also PGE2 in 3T3 murine fibroblasts (IC50 2.8-19.7 μg/mL). The crude n-hexane, dichloromethane and water extracts of the leaves and chromatographic fractions from the dichloromethane extract also showed modest antioxidant activity in the ORAC assay. GC-MS analysis of the n-hexane fraction showed the presence of the antibacterial compounds aromadendrene, spathulenol, β-caryophyllene, α-humulene and α-pinene and the anti-inflammatory compounds β-caryophyllene and spathulenol.
2.Chemical composition and antimicrobial activity of the essential oils of Onychopetalum amazonicum R.E.Fr.
de Lima BR1, da Silva FM1, Soares ER1, de Almeida RA1, da Silva Filho FA1, Pereira Junior RC1, Hernandez Tasco ÁJ2, Salvador MJ2, Koolen HH3, de Souza AD1, Pinheiro ML1. Nat Prod Res. 2016 Mar 31:1-4. [Epub ahead of print]
The essential oils from leaves, twigs and trunk bark of Onychopetalum amazonicum R.E. Fr. (Annonaceae), obtained by hydrodistillation, were analysed by GC and GC-MS, and also were evaluated for in vitro antimicrobial activity. Forty-one compounds, which correspond to 75.0-92.2% of the oil components, were identified. Major compounds were sesquiterpenes, including (E)-caryophyllene, caryophyllene oxide, spathulenol, α-gurjunene, allo-aromadendrene and α-epi-cadinol. The oils were evaluated for antimicrobial activities against four bacteria strains and five pathogenic fungi. The oil of the trunk bark exhibited good activity against Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 10538 and Kocuria rhizophila ATCC 9341, with a minimal inhibitory concentration of 62.5 μg/mL. The essential oil composition and the antimicrobial evaluation are reported for the first time for the genus Onychopetalum.
3.C15066. Composition and chemical variability of Ivoirian Polyalthia oliveri leaf oil.
Ouattara ZA1,2, Boti JB2, Ahibo CA2, Bekro YA3, Casanova J1, Tomi F1, Bighelli A1. Chem Biodivers. 2016 Feb 10. doi: 10.1002/cbdv.00004. [Epub ahead of print]
The chemical composition of 45 essential oil samples isolated from the leaves of Polyalthia oliveri harvested in three Ivoirian forests was investigated by GC-FID (Retention Indices measured on two columns of different polarities), and by 13 C-NMR, following a method developed in our laboratory. In total, 41 components were identified. The content of the main components varied drastically from sample to sample: (E)-β-caryophyllene (1.2-50.8%), α-humulene (0.6-47.7%), isoguaiene (0-27.9%), allo-aromadendrene (0-24.7%), germacrene B (0-18.3%), δ-cadinene (0.4-19.3%) and β-selinene (0.2-18.5%). The analysis of six oil samples selected in function of their chromatographic profiles is reported in detail. The 45 oil compositions were submitted to hierarchical cluster and principal components analysis, which allowed the distinction of three groups within the oil samples. The compositions of the oils from group I (15 samples) and II (12 samples) were dominated by (E)-β-caryophyllene and α-humulene, respectively.
4.Single- versus Multiple-Pest Infestation Affects Differently the Biochemistry of Tomato (Solanum lycopersicum 'Ailsa Craig').
Errard A1,2, Ulrichs C3, Kühne S4, Mewis I5, Drungowski M1, Schreiner M1, Baldermann S1,2. J Agric Food Chem. 2015 Nov 25;63(46):10103-11. doi: 10.1021/acs.jafc.5b03884. Epub 2015 Nov 11.
Tomato is susceptible to pest infestations by both spider mites and aphids. The effects of each individual pest on plants are known, whereas multiple-pest infestations have received little interest. We studied the effects of single- versus multiple-pest infestation by Tetranychus urticae and Myzus persicae on tomato biochemistry (Solanum lycopersicum) by combining a metabolomic approach and analyses of carotenoids using UHPLC-ToF-MS and volatiles using GC-MS. Plants responded differently to aphids and mites after 3 weeks of infestation, and a multiple infestation induced a specific metabolite composition in plants. In addition, we showed that volatiles emissions differed between the adaxial and abaxial leaf epidermes and identified compounds emitted particularly in response to a multiple infestation (cyclohexadecane, dodecane, aromadendrene, and β-elemene). Finally, the carotenoid concentrations in leaves and stems were more affected by multiple than single infestations.