Bioactividad de los extractos y aislamiento de los lignanos de las semillas de Centaurea dealbata

Centaurea dealbata Willd. (Family: Asteraceae) belongs to the big genus Centaurea that comprises ca. 500 species. Then-hexane, dichloromethane (DCM) and methanol (MeOH) extracts of the seeds of C. dealbata have been assessed forantioxidant activity and general toxicity using, respectively, the DPPH assay, and the brine shrimp lethality assay. Boththe DCM and the MeOH extract showed signifi cant levels of antioxidant activities with an RC50 value 6.8 x 10-2 and4.7 x 10-2 mg/mL, respectively. None of the extracts exhibited any signifi cant general toxicity (LD50 = >1000 mg/mL).Three major bioactive components of the MeOH extract were found to be the lignans, arctigenin, arctiin and matairesinoside.The structures of these lignans were elucidated by comprehensive spectroscopic analyses, and also by directcomparison with the respective published data. This is the fi rst report on the occurrence of arctiin and matairesionl inC. dealbata. The distribution of these lignans within the genus Centaurea has also been presented.La Centaurea dealbata Willd. (familia: Asteraceae) pertenece al género Centaurea, que comprende unas 500 especies.Para evaluar la actividad antioxidante y la toxicidad general de los extractos de n-hexano, diclorometano (DCM)y metanol (MeOH) de las semillas de C. dealbata se han utilizado, respectivamente, el ensayo DPPH y el ensayo deletalidad de gambas en salmuera. Tanto el extracto de DCM como el de MeOH presentaron niveles signifi cativosde actividad antioxidante, con valores de RC50 de 6,8 x 10-2 y 4,7 x 10-2 mg/mL, respectivamente. Ninguno de losextractos presentó una toxicidad general signifi cativa (LD50 = >1000 mg/mL). Se observó que los tres principalescomponentes bioactivos del extracto de MeOH fueron los lignanos arctigenina, arctiina y matairesinosida. Lasestructuras de estos lignanos se dilucidaron mediante análisis espectroscópicos exhaustivos y comparación directacon los datos respectivos publicados. Éste es el primer informe sobre la ocurrencia de arctiina y matairesinol en C.dealbata. También se presenta la distribución de estos lignanos dentro del género Centaurea

Structure-Based Design, Synthesis and Bioactivity of a New Anti-TNFα Cyclopeptide

As opposed to small molecules, macrocyclic peptides possess a large surface area and are recognised as promising candidates to selectively treat diseases by disrupting specific protein–protein interactions (PPIs). Due to the difficulty in predicting cyclopeptide conformations in solution, the de novo design of bioactive cyclopeptides remains significantly challenging. In this study, we used the combination of conformational analyses and molecular docking studies to design a new cyclopeptide inhibitor of the interaction between the human tumour necrosis factor alpha (TNFα) and its receptor TNFR-1. This interaction is a key in mediating the inflammatory response to tissue injury and infection in humans, and it is also an important causative factor of rheumatoid arthritis, psoriasis and inflammatory bowel disease. The solution state NMR structure of the cyclopeptide was determined, which helped to deduce its mode of interaction with TNFα. TNFα sensor cells were used to evaluate the biological activity of the peptide

Antiviral drug discovery : preparing for the next pandemic

Acknowledgements The authors also gratefully acknowledge financial support from the South African Medical Research Council (MRC) with funds received from the South African National Department of Health and the UK Government's Newton Fund (R. A. D., RL. M. G., K. C.), the UK Engineering and Physical Sciences Research Council EQATA (R. J. M. G.), the UK Global Challenge Research Fund (R. J. M. G., R. A. D.), the University of Cape Town (K. C.) and the South African Research Chairs Initiative of the Department of Science and Innovation, administered through the South African National Research Foundation (NRF) to K. C. (UID: 64767) and R. A. D. (UID: 87583). C. S. A. acknowledges financial support for SARS-CoV-2/Covid-19 research from UKMRC (CVG-1725-2020) and UKRI-DHSC (MR/Vo28464/1). The authors acknowledge Bronwyn Tweedie of the Rhodes University Print Services Unit who provided the graphics for Fig. 1 and thank Gordon Cragg for his insightful comments and encouragement during the preparation of this manuscript.Peer reviewedPublisher PD

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B.

Acknowledgements We acknowledge the mass spectrometry data received from the laboratory of Professor Pieter C. Dorrestein and Andrés Mauricio Caraballo Rodrígueze. Funding K.K., H.D and M.J. are grateful for the financial support of Leverhulme Trust-Royal Society Africa award (AA090088) and the jointly funded UK Medical Research Council–UK Department for International Development (MRC/DFID) Concordat Agreement African Research Leaders Award (MR/S00520X/1). A.P.N. is thankful for the award of a Ph.D. scholarship by the Organization for Women in Science for the Developing World (OWSD), the Swedish International Development Cooperation Agency (SIDA) and the Carnegie BANGA-Africa Project Award for a Ph.D. scholarship.Peer reviewedPublisher PD

Assessing the Effectiveness of Chemical Marker Extraction from Amazonian Plant Cupuassu (Theobroma grandiflorum) by PSI-HRMS/MS and LC-HRMS/MS.

Acknowledgments The authors acknowledge the institutional and financial support from the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES) and the Brazilian Research Council (CNPq). Funding This research received no external funding.Peer reviewedPublisher PD

Russell bodies in a skin biopsy: a case report

<p>Abstract</p> <p>Introduction</p> <p>The presence of eosinophilic bodies in a skin biopsy can be found in a variety of situations and this may present a challenge to the pathologist. The differential diagnosis of these eosinophilic structures include microorganisms such as histoplasmosis or cryptococcosis, fungi, Michaelis-Gutmann bodies, deposits of amyloid or immunoglobulins, colloid bodies or elastic bodies.</p> <p>Case presentation</p> <p>During a routine examination of a skin biopsy with actinic keratosis taken from the cheek of a 61-year-old man, clusters of eosinophilic bodies were seen within an inflammatory infiltrate in the dermis, both intracytoplasmic and extracellular. Using additional immunohistochemical staining, these structures were identified as polyclonal Russell bodies.</p> <p>Conclusion</p> <p>The differential diagnosis of intracytoplasmic eosinophilic structures in a skin biopsy includes Russell bodies, an uncommon finding that may be associated with chronic inflammatory conditions.</p

Mass spectrometry-based untargeted metabolomics approaches for comprehensive structural annotation of bioactive metabolites from bushy cashew (Anacardium humile) fruits

Funding Information: The authors acknowledge financial support from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the institutional and financial support. Publisher Copyright: © 2023Peer reviewedPostprin

Whole Genome Sequence of Dermacoccus abyssi MT1.1 Isolated from the Challenger Deep of the Mariana Trench Reveals Phenazine Biosynthesis Locus and Environmental Adaptation Factors

Dermacoccus abyssi strain MT1.1T is a piezotolerant actinobacterium that was isolated from Mariana Trench sediment collected at a depth of 10898 m. The organism was found to produce ten dermacozines (A‒J) that belonged to a new phenazine family and which displayed various biological activities such as radical scavenging and cytotoxicity. Here, we report on the isolation and identification of a new dermacozine compound, dermacozine M, the chemical structure of which was determined using 1D and 2D-NMR, and high resolution MS. A whole genome sequence of the strain contained six secondary metabolite-biosynthetic gene clusters (BGCs), including one responsible for the biosynthesis of a family of phenazine compounds. A pathway leading to the biosynthesis of dermacozines is proposed. Bioinformatic analyses of key stress-related genes provide an insight into how the organism adapted to the environmental conditions that prevail in the deep-sea

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

We thank Russell Gray, Subha Arjuna, and Shan Wang of the Marine Biodiscovery Centre, Aberdeen for assisting in NMR, mass spectrometry and Marfey analyses, respectively. We also appreciate the support of Dr. Soji Fakoya and Blessing Akinboyo of Ondo State University of Science and Technology, Okitipupa, Nigeria, for their support in the collection of sediments. This work was supported by funding from TETFund, Nigeria for a University Senate Based research.Peer reviewedPublisher PD