Eucaglobulin, A New Complex of Gallotannin and Monoterpene from Eucalyptus globulus

Eucaglobulin 1, a new complex of gallotannin and monoterpene, was isolated from the leaves of Eucalyptus globulus. Its structure was determined by spectral methods.

Antibacterial activity of the essential oils from the leaves of Eucalyptus globulus against Escherichia coli and Staphylococcus aureus

Objective:To examine the in vitro antimicrobial activities of essential oil of the leaves of Eucalyptus globulus(E.globulus).Methods:The essential oils of this plant were obtained by the hydrodistillation method.The inhibitory effects of this essential oil were tested against Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)by using agar disc diffusion and dilution broth methods.Results:The results obtained showed that essential oil of the leaves of E.globulus has antimicrobial activity against gram negative bacteria(E.coli)as well as gram positive bacteria(S.aureus).Conclusion:The encouraging results indicate the essential oil of E.globulus leaves might be exploited as natural antibiotic for the treatment of several infectious diseases caused by these two germs,and could be useful in understanding the relations between traditional cures and current medicines.

Transcript Level Analysis of Lignin and Flavonoid Biosynthesis Related Genes in <i>Eucalyptus globulus</i>

We have investigated a correlation of transcript abundances of key genes that influence the quality of wood and flavonoid biosynthesis, such as the two p-hydroxycinnamoyl-CoA:quinate shikimate p-hydroxycinnamoyl transferase (HCT) and the two chalcone synthases (CHS) from Eucalyptus globulus grown in a greenhouse. The EglHCT1 and EglHCT2 transcripts accumulated in stems of all ages, but to a lesser extent in leaves. On the other hand, EglCHS3 and EglCHS4 exhibited high transcript levels in leaves, roots and shoots, but low levels in the stem. A positive correlation (R2 > 0.70) was observed between the transcript levels of the EglHCT1, EglHCT2 genes and Klason lignin (KL) content. In addition, the sum of transcript levels of EglHCT1 and EglHCT2 genes were highly correlated to KL contents (R2 > 0.85). However, there is no relationship between transcript levels of two CHS genes and, KL or flavonoid contents. This may imply that lignin biosynthesis and flavonoid biosynthesis are independently regulated in E. globulus.

Antibacterial Activity of <i>Bougainvillea Glabra, Eucalyptus Globulus, Gnaphalium Attenuatum</i>, and Propolis Collected in Mexico

Bougainvillea glabra C., Eucalyptus globules Labill., and Gnaphalium attenuatum DC., as well as propolis, have been used in Mexican traditional medicine as a remedy to treat respiratory illnesses. There are few biological reports of such material collected in Mexico, despite the high demand for them as raw material for popular and industrial uses. The antibacterial activity of the plants and propolis studied here were evaluated against a panel of bacteria using three different methodologies: agar disc diffusion, macro and micro dilution methods. E. globules and G. attenuatum extracts showed the strongest active values (P > 0.05) in the agar disc diffusion method with a range of 8 - 22 mm inhibition zone, MIC values ranging from 25 - 250g/mL, and MBC values of 25 - 500g/mL obtained by macro and micro dilution methods. B. glabra extracts were active against E. coli, S. typhi, K. pneumoniae, S. aureus and S. agalactiae, with 8 - 13 mm inhibition zone, MICs ranging from 500 - 3000g/mL, and MBCs of 1000 - 3000g/mL. The propolis extract turned out to be active against E. coli, K. pneumoniae, S. aureus and S. agalactiae, with values of 7 - 12 mm, MICs of 1000 - 2000g/mL, and MBCs of 2000 - 2500g/mL. E. globules and G. attenuatum extracts were the most active in the three methodologies assayed. This is also the first time that the antibacterial activity of G. attenuatum has been experimentally demonstrated. The microdilution method showed to be more sensitive, less expensive and minor time-consuming technique compared with the other two.

Chemical Characterization and Biological Potential of the Essential Oil of Eucalyptus globulus Labill

Oxidation of lipids in various products,along with the growth of medically important pathogens,has led to a search for medicinal plants with antioxidant and antimicrobial activities.As a result,the aim of this study was to evaluate the antioxidant and antibacterial activity of the essential oil of Eucalyptus globulus(EO-Eg).Antioxidant activity was assessed by using the 2,2-diphenyl-1-picrylhydrazyl hydrate(DPPH)assay method.Existing components were identified through gas chromatography-mass spectrometry(GC-MS)analysis.Antibacterial activity and minimum inhibitory concentration(MIC)were assessed by using the broth microdilution method with standard multidrug-resistant bacterial strains.The main EO-Eg compounds identified by GC-MS were isopulegol,citronellal,and citronellol,which are primarily used in the industrial sectors.EO-Eg demonstrated excellent antioxidant activity with an effective concentration(EC50)of 4.48μL/mL owing to the presence of phenolic compounds.Regarding antibacterial activity,the EO-Eg displayed a broad antimicrobial spectrum of antimicrobial activity across the different resistance phenotypes analyzed.The most notable antibacterial activity was observed against Staphylococcus aureus 169 MRSA(MIC=0.0625%).As a result,our findings suggest that EO-Eg has antioxidant and antibacterial potential against hospital-acquired multidrug-resistant pathogens,which may be correlated with its major components.

Response of soil respiration to a severe drought in Chinese Eucalyptus plantations

Extreme droughts can adversely affect the dynamics of soil respiration in tree plantations. We used a severe drought in southwestern China as a case study to estimate the effects of drought on temporal variations in soil respiration in a plantation of Eucalyptus globulus. We documented a clear seasonal pattern in soil respiration with the highest values (100.9 mg C-CO2 m(-2) h(-1)) recorded in June and the lowest values (28.7 mg C-CO2 m(-2) h(-1)) in January. The variation in soil respiration was closely associated with the dynamics of soil water driven by the drought. Soil respiration was nearly twice as great in the wet seasons as in the dry seasons. Soil water content accounted for 83-91% of variation in soil respiration, while a combined soil water and soil temperature model explained 90-99% of the variation in soil respiration. Soil water had pronounced effects on soil respiration at the moisture threshold of 6-10%. Soil water was strongly related to changes in soil parameters (i.e., bulk density, pH, soil organic carbon, and available nitrogen). These strongly influenced seasonal variation in soil respiration. We found that soil respiration was strongly suppressed by severe drought. Drought resulted in a shortage of soil water which reduced formation of soil organic carbon, impacted soil acid-base properties and soil texture, and affected soil nutrient availability.

Note on Glycaspis brimblecombei Moore (Hemiptera Psyllidae): A new pest of Eucalyptus in Greece

Leaves of eucalyptus infested by Glycaspis brim-blecombei Moore were found on river red gum (E. camaldulensis) and blue gum (E. globulus) trees in Attiki and Chania region, Greece. The psyllid is recorded for the first time in Greece. Brief information about this psyllid is provided.

Factors determining the occupancy of nest-boxes by Great Tits(Parus major)in eucalypt plantations

Providing nest-boxes as surrogate tree cavities can be of great importance to increase the breeding populations of cavity-nesting birds in managed forests.However,the exact placement of nest-boxes should be taken into consideration to enhance their occupancy according to species-specific preferences.In this study,we investigated which factors can better predict nest-box occupancy by the Great Tit(Parus major)in eucalypt plantations.We used generalised linear mixed-effects models to analyse the influence of topography,nest-box positioning,vegetation cover and landscape variables on three-year occupancy records from 80 newly provided nest-boxes.Non-random patterns of nest-box occupancy were found with respect to all categories except topography.Results suggest that Great Tits prefer to occupy high-placed nest-boxes,close to areas that can provide them with supplementary resources either within or in the vicinity of the stand(i.e.,trees other than eucalypts,riparian vegetation,and large patches of adjacent habitats).Overall,this study provides important recommendations for nest-box placement and spatial distribution in managed forests and enhances the potential of nest-box interventions as a biodiversity offset and management tool.

Lignocellulosic Micro and Nanofibrillated Cellulose Produced by Steam Explosion for Wood Adhesive Formulations

The reinforcing impact of Lignocellulosic micro and nanofibrillated cellulose(L-MNFCs)obtained from Eucalyp-tus Globulus bark in Urea-Formaldehyde UF adhesive was tested.L-MNFCs were prepared by an environmentally friendly,low-cost process using a combination process involving steam explosion followed by refining and ultra-fine grinding.Obtained L-MNFCs showed a web-like morphology with some aggregates and lignin nanodroplets.They present a mixture of residual fibers and fine elements with a width varying between 5 nm to 20μm,respec-tively.The effects of the addition of low amounts of L-MNFCs(1%wt.)on the properties of three different adhe-sives(Urea-Formaldehyde UF,Phenol-Formaldehyde PF,and Tannin-Hexamine TH)were studied by the evolution of the pH,the viscosity,and the mechanical properties.Results showed that the viscosity of PF and UF adhesives increased with the addition of L-MNFCs,unlike TH.Meanwhile,the addition led to better mechan-ical behavior for the three adhesives.Particleboards were then prepared using modified UF with L-MNFCs and tested.Results showed that an amount of 1%wt.of L-MNFCs was sufficient to increase the internal bonding by≈67%,the modulus of elasticity by≈43%,and the modulus of rupture by≈29%.

Status of and threats to the Black-winged Lovebird(Agapornis taranta) in Entoto Natural Park and Bole Sub-City,Addis Ababa,Ethiopia

A study of the population status of and threats to the Black-winged Lovebird(Agapornis taranta) was carried out from September 2008 to February 2009 in Entoto Natural Park(ENP) and in Bole SubCity,Addis Ababa,Ethiopia.A point transect count technique was employed to examine the status of the lovebirds.An average total of 58 birds was recorded of which 46 were counted in Bole Sub-City and 12 in Entoto Natural Park areas.The maximum number recorded during our census was 57 in the dry season and 15 in the wet season in Bole Sub-City and Entoto Natural Park,respectively.The ratio of adult males to adult females in Entoto Natural Park was 1:0.71 and 1:0.60,and 1:0.76 and 1:0.78 in Bole Sub-City during both wet and dry seasons,respectively.The seasonal variation and difference in sex ratios between males and females was not significant(p > 0.05) at either of the study sites.The threat for the Blackwinged Lovebird or other birds in Entoto Natural Park is due to the fragmentation of natural habitats,thus decreasing food sources,owing to the domination of eucalyptus(Eucalyptus globulus) trees in the area.Grazing by livestock,intensive farming practices and deforestation by the local community have contributed greatly to the degradation of the land resulting in erosion,thus devastating the habitat of the Natural Park.The vegetation cover of Entoto Natural Park and urban gardens should be managed effectively for the survival of the avian fauna of the area.

干燥方法对几种植物染色能力的影响

本文研究了蓝桉树皮和洋葱皮干燥方法对化学浆染色能力的影响。这些植物材料含有丰富的多酚类化合物,如单宁酸、花青素和其他黄酮类化合物,是天然的着色剂。本文研究了不同条件下的自然干燥、空气干燥和冷冻干燥三种方法。此外,还研究了提取条件对两种植物样本染色能力的影响。自然干燥的植物样本与空气干燥和冷冻干燥的植物样本相比,呈现出很弱的染色能力。空气干燥和冷冻干燥具有相似的染色结果。在空气干燥实验中,在低温(T=30℃)和高湿度(95%RH)条件下干燥可以获得很强的染色能力。而对于提取条件,染色能力主要取决于提取温度,而停留时间对染色能力影响甚微。