1,624 research outputs found
Fixed and volatile constituents oF genus Croton plants: C. adenoCalyx Baill -euphorBiaceae
aBstract This work describes the phytochemical analysis of Croton adenocalyx Baill (Euphorbiaceae), a plant that is representative of the species from Ceará State (Brazil). The GC-MS analysis of the essential oil, obtained by hydrodistillation of the leaves from C. adenocalyx, allowed the identification of eleven volatile constituents; the main components were identified as α-pinene (32.63%); bicyclogermacrene (13.96%); trans-caryophyllene (10.23%); germacrene D (10.14%); β-pinene (10.11%) and β-elemene (8.31%). The chromatographic purification of the ethanolic extract from the trunk bark, allowed the isolation and identification of the 6-methoxy-7-hydroxycoumarin (1) and 3´,5-dihydroxy-3,4´,7-trimethoxyflavone (2). Keywords: Euphorbiaceae, Croton adenocalyx, Essential oil, GC-MS, Flavonoid, Coumarin. resumen Este trabajo describe el análisis fitoquímico de Croton adenocalyx Baill (Euphorbiaceae), una planta representativa de las especies del Estado de Ceará-Brasil. El análisis por CG-EM del aceite esencial, obtenido por hidrodestilación de las hojas de C. adenocalyx Baill, permitió la identificación de diez constituyentes volátiles. Los componentes mayoritarios fueron identificados como α-pineno (32.63%), biciclogermacreno (13.96%), trans-cariofileno (10.23%), germacreno D (10.14%), β-pineno (10.11%) y β-elemeno (8.31%). La purificación cromatográfica del extracto etanólico de la corteza del tronco, permitió aislar e identificar la coumarina 6-metoxi-7-hidroxicumarina (1) y el 3´,5-dihidroxi-3,4´,7-trimetoxiflavona (2)
Intragenic antimicrobial peptides (IAPs) from human proteins with potent antimicrobial and anti-inflammatory activity
Following the treads of our previous works on the unveiling of bioactive peptides encrypted
in plant proteins from diverse species, the present manuscript reports the occurrence of four
proof-of-concept intragenic antimicrobial peptides in human proteins, named Hs IAPs.
These IAPs were prospected using the software Kamal, synthesized by solid phase chemistry,
and had their interactions with model phospholipid vesicles investigated by differential
scanning calorimetry and circular dichroism. Their antimicrobial activity against bacteria,
yeasts and filamentous fungi was determined, along with their cytotoxicity towards erythrocytes.
Our data demonstrates that Hs IAPs are capable to bind model membranes while
attaining α-helical structure, and to inhibit the growth of microorganisms at concentrations
as low as 1μM. Hs02, a novel sixteen residue long internal peptide (KWAVRIIRKFIKGFISNH2)
derived from the unconventional myosin 1h protein, was further investigated in its
capacity to inhibit lipopolysaccharide-induced release of TNF-α in murine macrophages.
Hs02 presented potent anti-inflammatory activity, inhibiting the release of TNF-α in LPSprimed
cells at the lowest assayed concentration, 0.1 μM. A three-dimensional solution
structure of Hs02 bound to DPC micelles was determined by Nuclear Magnetic Resonance.
Our work exemplifies how the human genome can be mined for molecules with biotechnological
potential in human health and demonstrates that IAPs are actual alternatives to antimicrobial
peptides as pharmaceutical agents or in their many other putative applications
Context-dependence of race self-classification : results from a highly mixed and unequal middle-income country
Ethnic-racial classification criteria are widely recognized to vary according to historical, cultural and political contexts. In Brazil, the strong influence of individual socio-economic factors on race/colour self-classification is well known. With the expansion of genomic technologies, the use of genomic ancestry has been suggested as a substitute for classification procedures such as self-declaring race, as if they represented the same concept. We investigated the association between genomic ancestry, the racial composition of census tracts and individual socioeconomic factors and self-declared race/colour in a cohort of 15,105 Brazilians. Results show that the probability of self-declaring as black or brown increases according to the proportion of African ancestry and varies widely among cities. In Porto Alegre, where most of the population is white, with every 10% increase in the proportion of African ancestry, the odds of self-declaring as black increased 14 times (95%CI 6.08–32.81). In Salvador, where most of the population is black or brown, that increase was of 3.98 times (95%CI 2.96–5.35). The racial composition of the area of residence was also associated with the probability of selfdeclaring as black or brown. Every 10% increase in the proportion of black and brown inhabitants in the residential census tract increased the odds of self-declaring as black by 1.33 times (95%CI 1.24–1.42). Ancestry alone does not explain self-declared race/colour. An emphasis on multiple situational contexts (both individual and collective) provides a more comprehensive framework for the study of the predictors of self-declared race/colour, a highly relevant construct in many different scenarios, such as public policy, sociology and medicine
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