Mentha suaveolens Ehrh. (lamiaceae) essential oil and Its main constituent piperitenone oxide: biological activities and chemistry

Since herbal medicines play an important role in the treatment of a wide range of diseases, there is a growing need for their quality control and standardization. Mentha suaveolens Ehrh. (MS) is an aromatic herb with fruit and a spearmint flavor, used in the Mediterranean areas as a traditional medicine. It has an extensive range of biological activities, including cytotoxic, antimicrobial, antioxidant, anti-inflammatory, hypotensive and insecticidal properties, among others. This study aims to review the scientific findings and research reported to date on MS that prove many of the remarkable various biological actions, effects and some uses of this species as a source of bioactive natural compounds. On the other hand, piperitenone oxide (PO), the major chemical constituent of the carvone pathway MS essential oil, has been reported to exhibit numerous bioactivities in cells and animals. Thus, this integrated overview also surveys and interprets the present knowledge of chemistry and analysis of this oxygenated monoterpene, as well as its beneficial bioactivities. Areas for future research are suggested

Antioxidant, antifungal, antibiofilm, and cytotoxic activities of Mentha spp. essential oils

Since ancient times, plants have been used to preserve food, or for their health properties. Essential oils are complex mixtures of volatile compounds that are obtained from botanical material, specifically from aromatic plants. Lamiaceae is one of the most important families in the production of essential oils, as it has both antioxidant and antimicrobial properties. The essential oils of Mentha (the Lamiaceae family) have been extensively studied for their biological actions. In this review, we report the antioxidant, antifungal, antibiofilm, and cytotoxic properties of Mentha spp. essential oils. The first objective is to provide comprehensive information about the use of essential oils in the treatment of fungal infections, or as antioxidants and integrative anticancer therapy. The second is to explore the evidence supporting its effectiveness in treating diseases without causing any serious adverse reactions

Overview of Genus Prosopis Toxicity Reports and its Beneficial Biomedical Properties

Secondary plant metabolites are regarded as promising sources of plant-protecting substances and they are one of the most important lines of plant defense against pests. The range of cellular targets for these substances is very wide and covers metabolic pathways, macromolecules and organelles. In consequence, the plant derivatives study represents a critical situation in which toxic effects against other organisms need to be evaluated in relation to its biological benefits. The genus Prosopis (Fabaceae) include 44 species and is considered among the world’s most damaging invasive species. The genus had been found in 129 countries globally and many more countries are climatically suitable. Prosopis physiology evidences a wide range of adaptability, shows the capability to growth in several adverse conditions, accumulates heavy metals and synthetizes chemical defences. Curiously, since antiquity, some Prosopis species around the world were described as important source of ethnopharmacological treatments for several illnesses. Toxicity against prokaryote microorganisms, fungus, parasites, mosquitoes, vertebrate animals and humans is revised in the current work. In accordance to the reviewed literature, it is possible to conclude that more specific research could make Prosopis species an important source of nutraceuticals and phytopharmaceutical compounds. Moreover, by its selective toxic effects, plant derivatives can be used as important source of new and successful bioactive molecules.Fil: Persia, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Rinaldini, Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Hapon, María Belén. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Gamarra Luques, Carlos Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentin

Chemical Communication of Antibiotic Resistance by Highly Resistant Bacteria.

The overall antibiotic resistance of a bacterial population results from the combination of a wide range of susceptibilities displayed by subsets of bacterial cells. Bacterial heteroresistance to antibiotics has been documented for several opportunistic Gram-negative bacteria, but the mechanism of heteroresistance is unclear. I use Burkholderia cenocepacia as a model opportunistic bacterium to investigate the implications of heterogeneity in the response to the antimicrobial peptide polymyxin B (PmB) and also other bactericidal antibiotics. Here, I report that B. cenocepacia is heteroresistant to PmB. Population analysis profiling identified B. cenocepacia subpopulations arising from a seemingly homogenous culture that are resistant to higher levels of PmB than the rest of the cells in the culture, and protect the more sensitive cells from killing, as well as sensitive bacteria from other species, such as Pseudomonas aeruginosa and Escherichia coli. Communication of resistance depended on upregulation of putrescine synthesis and YceI, a widely conserved low-molecular weight secreted protein. Deletion of genes for the synthesis of putrescine and YceI abrogate protection, while pharmacologic inhibition of putrescine synthesis reduced resistance to PmB. Polyamines and YceI were also required for heteroresistance of B. cenocepacia to various bactericidal antibiotics. I propose that putrescine and YceI resemble danger infochemicals whose increased production by a bacterial subpopulation, becoming more resistant to bactericidal antibiotics, communicates higher level of resistance to more sensitive members of the population of the same or different species. Putrescine protects from antibiotics through its ability to compete with PmB for surface binding and protection against antibiotic-induced oxidative stress. YceI proteins are conserved bacterial lipocalins or “bacteriocalins”. Bacteriocalins from different Gram-positive and Gram-negative bacteria are involved in the response to hydrophobic or amphiphilic antibiotics (PmB, rifampicin, norfloxacin and ceftazidime) but not hydrophilic ones (such as gentamicin). This effect is achieved by their preferential binding affinity to hydrophobic moieties. Together, my findings uncover a novel, non-genetic and cooperative mechanism of transient increase in resistance chemically communicated from more resistant members of heterogeneous populations to less resistant bacteria of the same or other species. This multifactorial mechanism of communication of antibiotic resistance offers novel targets for antimicrobial intervention

Studies on the sulfation of cellulose α-lipoate and ability of the sulfated product to stabilize colloidal suspensions of gold nanoparticles

© 2015 Elsevier Ltd. A versatile method for the synthesis of cellulose α-lipoate with a low degree of substitution (DS) has been developed using N,N-dimethylacetamide (DMA)/LiCl as a solvent and N,N′-carbonyldiimidazole (CDI) as an esterification reagent. The cellulose α-lipoate with DS of α-lipoate groups of 0.26 was converted with sulfur trioxide-pyridine complex in dimethyl sulfoxide (DMSO) as solvent. The sulfation is accompanied by an unexpected partial oxidation of the disulfide moiety leading to the formation of the corresponding stereoisomers of S-oxides. The resulting mixture of water-soluble cellulose α- and β-lipoate sulfate possesses a DS of sulfuric acid half ester groups of 1.78. This cellulose-α/β-lipoate sulfate derivative can be used as an effective stabilizer and solubilizer for the formation of colloidal suspensions of gold nanoparticles formed in situ in aqueous solution

Synthesis, characterization and bioactivity of selected metal complexes with imine ligands

The chemistry of complex compounds containing imine ligands is attracting significant attention from researchers today. In this work, complexes of selected transition metals (Cu, Co, Ni and Fe) with imines based on ninhydrin and amino acids methionine and cysteine were synthesized. FTIR and UV/VIS spectroscopy were used for structural characterization. Antioxidant activity of the complex was analyzed by the FRAP method. The synthesized compounds showed a significant reducing ability, ranging from 221.94 to 756.30 µmol/L. In vitro antimicrobial activity was tested on strains from the ATCC collection. Inhibitory activity against the tested microorganisms was recorded, and the zones of inhibition ranged from 10-24 mm. Preliminary research shows that these compounds have biological potency, but more detailed in vitro and in vivo studies are required for their use.</p

Environmental remediation promoted by silver nanoparticles biosynthesized by eucalyptus leaves extract

A simple and low-cost green synthesis method was optimized to prepare stable silver nanoparticles (AgNP) using aqueous Eucalyptus globulus leaves extract. This green method allows to obtain AgNP with spherical morphology and variable size around 25 nm, and it is dependent of the reaction temperature and concentration of the plant extract. AgNP stability was followed during 3 months by zeta potential measurements and a negative zeta range from 30.7 to 33.6 was determined. Biogenic-stabilized AgNP exhibited dual-functional properties as effective in environmental remediation with bacterial growth inhibition and dye photodegradation. Staphylococcus aureus and Escherichia coli were tested for antibacterial activity, and considerable inhibitory activity was found. High photocatalytic degradation of indigo carmine (IC) dye was performed in the presence of the AgNP as catalysts under sunlight irradiation. The degradation efficiency after 2 h of reaction was 37 %, 83 % and 98 % in the presence of UV light, visible light and sunlight irradiation, respectively. The germination of corn kernels test was used to determine the toxicity of the treated IC solutions and the results showed low toxicity after the photodegradation process.V.R. thanks to Fundação para Ciência e Tecnologia, FCT (Portugal) for her Ph.D. grant (SFRH/BD/141073/2018). P⋅F-S. would like to express their gratitude to the Spanish Ministry of Economy and Competitiveness for their postdoctoral grant (Reference FJC2021-046978-I). This research work has been funded by FCT/MCTES (PIDDAC) over the projects: CQ-UM (UID/QUI/0686/2020), CEB (UIDB/04469/2020) and LABBELS (LA/P/0029/2020), and project BioTecNorte (operation NORTE-01-0145-FEDER-000004), supported by the Northern Portugal Regional Operational Program (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

Synthesis, Characterization and Elucidation of the Structure–Activity Relationship of Heteroatom Donor Ligands and Their Complexes Derived From Substituted Dithiocarbazate Derivatives

Four new substituted dithiocarbazate ligands [S-napthalen-2-ylmethyldithiocarbazate (SNMDTC), S-quinolin-2-ylmethyl-dithiocarbazate (SQ2MDTC), Sbenzyl- N-benzyldithiocarbazate (SBNBDTC) and S-methyl-N-benzyldithiocarbazate (SMNBDTC)], eight series of isomeric Schiff bases derived from different types of S-substituted dithiocarbazate and their metal complexes were successfully synthesized and characterized. Eighteen structures were determined using single crystal X-ray diffraction analysis. These newly synthesized compounds were systematically designed to form structurally heterogeneous compounds for QSAR study. Schiff bases were derived from condensation of isomeric aldehydes and ketones, 3- and 4-methylacetophenone and 2-, 3- and 4-acetylpyridine with different substituted dithiocarbazate compounds. Upon complexation, all Schiff bases formed bis chelated (NS donor) complexes except for the uninegative tridentate, S-napthalen- 2yl methyl-β-N-(2-acetylpyridine)dithiocarbazate (SNM2AP) that coordinated with metal ions via the azomethine nitrogen atom, the pyridyl nitrogen atom and the thiolo sulfur (NNS donor) Some of these newly synthesized compounds exhibited significant activities towards selective strains of pathogens and marked cytotoxicity when assayed against breast cancer estrogen receptor positive, MCF-7 and breast cancer estrogen receptor negative, MDA-MB-231 cell lines. The biological activities of the isomeric Schiff bases and their complexes were investigated. Most of the complexes exhibited higher activity compared to their parent ligands upon complexation with metal ions. The cytotoxicity data for all the compounds were used to construct QSAR model in an attempt to elucidate the relationship between structure and bioactivity. Satisfactory QSAR models were developed focusing on a few of the informative descriptors based on a wide set of relatively heterogeneous compounds as evidenced with value r2>0.6 and r2 CV> 0.5

Comparative analysis of antimicrobial and proteolytic activity of lactic acid bacteria isolated from Zlatar cheese

Tradicionalni zlatarski sir pripada grupi belih, polutvrdih sireva proizvedenih u domaćinstvu. Sir se proizvodi od nepasterizovanog kravljeg mleka bez dodavanja bilo kakvih poznatih starter kultura. Ukupno je izolovano 253 Gram pozitivnih i katalaza negativnih bakterija mlečne kiseline (BMK). Rezultati su pokazali da 70 od 253 analiziranih izolata proizvodi antimikrobna jedinjenja poznatih kao bakteriocini. Većina izolata koji pripadaju rodovima Lactococcus i Enterococcus, kao i izolati vrsta Lactobacillus plantarum i Lb. brevis ne sintetišu ekstracelularne proteinaze. Nasuprot njima, izolati prodvrste Lb. paracasei subsp. paracasei pokazuju veoma dobru proteolitičku aktivnoist. Pokazano je da ne postoji korelacija između dobre proteolitičke i antimikrobne aktivnosti u većini izolata.Traditional artisan Zlatar cheese belongs to the group of white, semi hard home-made cheeses, which are produced from no pasteurized cow's milk, without addition of any known bacterial starter culture. In total, 253 Gram-positive and catalase negative lactic acid bacteria (LAB) were isolated. Results showed that 70 out of 253 analyzed isolates produced antimicrobial compounds known as bacteriocins. Most isolates from genera Lactococcus and Enterococcus, and isolates belonging to species Lactobacillus plantarum and Lb. brevis, do not synthesize extracellular proteinase. In contrast, isolates from subspecies Lb. paracasei subsp. paracasei showed very good proteolytic activity. It was observed that good proteolytic activity of isolates was not in correlation with their good antimicrobial activity in the most of isolates