133 research outputs found
ANTIMICROBIAL ACTIVITY OF ESSENTIAL OILS OF OCIMUM GRATISSIMUM L. FROM DIFFERENT POPULATIONS OF KENYA
Hydro-distilled volatile oils from the leaves of Ocimum gratissimum L. (Lamiaceae) of 13 populations of different silvicultural zones were evaluated for antimicrobial activity against Gram positive (Staphylococcus aereus, Bacillus spp.) and Gram negative (Escherichia coli, Pseudomonas aeruginosa, Samonella typhi, Klebisiella pneumoniae, Proteus mirabilis) bacteria and a pathogenic fungus, Candida albicans. All the essential oils are active to the tested microbiles with different strength. The highest antimicrobial activity against Gram positive bacteria (Staphylococcus aureus) and Gram negative bacteria (Pseudomonas aeruginosae and Proteus mirabilis) was observed from the eastern Kenya (Meru) oil. Meru oil was the best and its effectiveness was consistent on nearly all the microbes tested. The oil from the plant growing in the coastal region of Kenya (Mombasa) showed the best effect only on Gram negative bacteria (Escherichia coli and Proteus mirabilis). Both oils (Meru and Mombasa) were dominated by monoterpenes accounting for 92.48 % and 81.37 % respectively. The monoterpene fraction was characterized by a high percentage of eugenol (68.8 %) for Meru oil and 74.10 % for Mombasa oil. The other major monoterpene was methyl eugenol (13.21 %). Camphor (0.95 %) was observed only in the Meru oil. (Cis)-Ocimene, (trans)-ocimene and β-pinene were present in both Meru and Mombasa oils. The sesquiterpenes present in fairly good amounts in both oils were germacrene D and (trans)-caryophyllene. The minor sesquiterpenes were α-farnesene (0.85 %) and β-bisabolene (0.74 %) which were present in the Meru oil only
A Collective Variable for the Rapid Exploration of Protein Druggability
An efficient molecular simulation
methodology has been developed
for the evaluation of the druggability (ligandability) of a protein.
Previously proposed techniques were designed to assess the druggability
of crystallographic structures and cannot be tightly coupled to molecular
dynamics (MD) simulations. By contrast, the present approach, JEDI
(<u>J</u>ust <u>E</u>xploring <u>D</u>ruggability at protein <u>I</u>nterfaces),
features a druggability potential made of a combination of empirical
descriptors that can be collected “on-the-fly” during
MD simulations. Extensive validation studies indicate that JEDI analyses
discriminate druggable and nondruggable protein binding site conformations
with accuracy similar to alternative methodologies, and at a fraction
of the computational cost. Since the JEDI function is continuous and
differentiable, the druggability potential can be used as collective
variable to rapidly detect cryptic druggable binding sites in proteins
with a variety of MD free energy methods. Protocols for applications
to flexible docking problems are outlined
High-density nitrogen inclusions in barite from a giant siderite vein: implications for Alpine evolution of the Variscan basement of Western Carpathians, Slovakia.
International audienc
Ligand Fluorination to Optimize Preferential Oxidation of Carbon Monoxide by Water-Soluble Rhodium Porphyrins
Catalytic, low temperature preferential oxidation (PROX) of carbon monoxide by aqueous [5,10,15,20-tetrakis- (4-sulfonatophenyl)-2,3,7,8,12,13,17,18-octafluoroporphyrinato]- rhodium(III) tetrasodium salt, (1[Rh(III)]) and [5,10,15, 20-tetrakis(3-sulfonato-2,6-difluorophenyl)-2,3,7,8,12,13, 17,18-octafluoroporphyrinato]rhodium(III) tetrasodium salt, (2[Rh(III)]) is reported. The PROX reaction occurs at ambient temperature in buffered (4 ≤ pH ≤ 13) aqueous solutions. Fluorination on the porphyrin periphery is shown to increase the CO PROX reaction rate, shift the metal centered redox potentials, and acidify ligated water molecules. Most importantly, β-fluorination increases the acidity of the rhodium hydride complex (pKa = 2.2 ± 0.2 for 2[Rh-D]); the dramatically increased acidity of the Rh(III) hydride complex precludes proton reduction and hydrogen activation near neutral pH, thereby permitting oxidation of CO to be unaffected by the presence of H2. This new fluorinated water-soluble rhodium porphyrin-based homogeneous catalyst systempermits preferential oxidation of carbonmonoxide in hydrogen gas streams at 308 K using dioxygen or a sacrificial electron acceptor (indigo carmine) as the terminal oxidant
Disseminated intraparenchymal microgranulomas in the brainstem in central nervous system sarcoidosis
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