Bioactivity-guided fractionation of the EtOAc extract from leaves of Piper crassinervium yielded three prenylated hydroquinones together with two known flavanones naringenin and sakuranetin. Their structures were determined by means of spectroscopic analysis (NMR, IR, UV and MS) including two-dimensional NMR spectroscopy experiments (1H-1H COSY, HMQC, HMBC and NOESY). The antifungal activity was determined by direct bioautography against Cladosporium cladosporioides and C. sphaerospermum.
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http://dx.doi.org/10.1016/s0031-9422(03)00299-1 | DOI Listing |
Plants (Basel)
May 2023
Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Sede Bogotá, Bogotá 111321, Colombia.
The present study describes the anti-biofilm and quorum sensing (QS) inhibitory potential of extracts and chemical constituents from . Antibiofilm potential was determined through crystal violet assay against , while QS inhibition efficacy was determined through violacein inhibition assay using as a bacterial model. Additionally, this study reports the effects of the chemical constituents isolated in against various virulent factors associated with QS, such as the percentage decrease in pyocyanin, elastase, and protease production.
View Article and Find Full Text PDFJ Org Chem
June 2023
Organic Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
We report an improved synthetic protocol for hydroxy methyl-derived polysubstituted furans employing Bi(III)-catalyzed dehydrative cycloisomerization of α-hydroxy oxetanyl ketones. This procedure provides rapid access (within 5 min) to highly substituted furans with exceptional functional group diversity, excellent yields, generality, scalability, and operationally simple reaction conditions. Further, it demonstrated the utility of this method in the first enantioselective total synthesis of furyl-hydroquinone-derived biologically potent natural products shikonofurans J, D, E, and C in seven linear steps, starting from readily available building blocks of 2,5-dihydroxy acetophenone and 3-oxetanone employing chiral-phosphoric acid (TRIP)-catalyzed asymmetric prenylation as a key step to induce the chirality.
View Article and Find Full Text PDFPLoS One
February 2023
Instituto de Biociências, Universidade Estadual Paulista, UNESP, São Vicente, SP, Brazil.
Multiple drug resistance (MDR) bacterial strains are responsible by 1.2 million of human deaths all over the world. The pathogens possess efficient enzymes which are able to mitigate the toxicity of reactive oxygen species (ROS) produced by some antibiotics and the host immune cells.
View Article and Find Full Text PDFAntioxidants (Basel)
February 2022
Departament de Farmacologia, Facultat de Farmàcia, Universitat de València, Av. Vicent Andrés Estellés s/n, 46100 Burjassot, Spain.
Secondary metabolites derived from hydroquinone are quite rare in nature despite the original simplicity of its structure, especially when compared to other derivatives with which it shares biosynthetic pathways. However, its presence in a prenylated form is somewhat relevant, especially in the marine environment, where it is found in different algae and invertebrates. Sometimes, more complex molecules have also been identified, as in the case of polycyclic diterpenes, such as those possessing an abietane skeleton.
View Article and Find Full Text PDFBiomolecules
May 2021
Institute of Pharmacy/Pharmacognosy, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria.
The class of demosponges is the biggest and most diverse of all described sponge species and it is reported to produce a plethora of chemically different metabolites with interesting biological activities. The focus of the present study was to investigate the chemical composition of two Mediterranean demosponges, targeting their brominated compounds and prenylated hydroquinones, compounds with interesting cytotoxic and anti-microbial properties. In order to gain a deeper insight into the chemical diversity of their metabolites and their activities, 20 pure secondary metabolites including new natural products were isolated from two different species ( and sp.
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