Publications by authors named "Monica Tallarico Pupo"

Covering: September 1964 to June 2023Bacteria and fungi living in symbiosis with insects have been studied over the last sixty years and found to be important sources of bioactive natural products. Not only classic producers of secondary metabolites such as and other members of the phylum Actinobacteria but also numerous bacteria from the phyla Proteobacteria and Firmicutes and an impressive array of fungi (usually pathogenic) serve as the source of a structurally diverse number of small molecules with important biological activities including antimicrobial, cytotoxic, antiparasitic and specific enzyme inhibitors. The insect niche is often the exclusive provider of microbes producing unique types of biologically active compounds such as gerumycins, pederin, dinactin, and formicamycins.

View Article and Find Full Text PDF

Aspergillus fumigatus is a saprophytic fungus that can cause a variety of human diseases known as aspergillosis. Mycotoxin gliotoxin (GT) production is important for its virulence and must be tightly regulated to avoid excess production and toxicity to the fungus. GT self-protection by GliT oxidoreductase and GtmA methyltransferase activities is related to the subcellular localization of these enzymes and how GT can be sequestered from the cytoplasm to avoid increased cell damage.

View Article and Find Full Text PDF

Symbiotic interactions between microorganisms and social insects have been described as crucial for the maintenance of these multitrophic systems, as observed for the stingless bee and the yeast sp. SDBC30G1. The larvae of ingest fungal filaments of sp.

View Article and Find Full Text PDF

is a saprophytic fungus that can cause a variety of human diseases known as aspergillosis. Mycotoxin gliotoxin (GT) production is important for its virulence and must be tightly regulated to avoid excess production and toxicity to the fungus. GT self-protection by GliT oxidoreductase and GtmA methyltransferase activities is related to the subcellular localization of these enzymes and how GT can be sequestered from the cytoplasm to avoid increased cell damage.

View Article and Find Full Text PDF

Stingless bees (Meliponini) are a monophyletic group of eusocial insects inhabiting tropical and subtropical regions. These insects represent the most abundant and diversified group of corbiculate bees. Meliponini mostly rely on fermentation by symbiont microbes to preserve honey and transform pollen in stored food.

View Article and Find Full Text PDF

Social insects establish complex interactions with microorganisms, some of which play defensive roles in colony protection. The important role of pollinators such as the stingless bee in nature encouraged us to pursue efforts to study its associated microbiota. Here we describe the discovery of two novel cyclic hexadepsipeptides, meliponamycin A () and meliponamycin B (), from sp.

View Article and Find Full Text PDF

Objective: To examine whether free (3-PD-5) and/or liposomal (3-PD-5) 6,7-dihydroxy-3-[3',4'-methylenedioxyphenyl]-coumarin (3-PD-5) (1) modulate the effector functions of neutrophils from patients with rheumatoid arthritis under remission (i-RA) and with active disease (a-RA), in vitro; and (2) exert anti-inflammatory effect in a rat model of zymosan-induced acute joint inflammation.

Methods And Results: Incorporation of 3-PD-5 into unilamellar liposomes of soya phosphatidylcholine and cholesterol was efficient (57.5 ± 7.

View Article and Find Full Text PDF

The Brazilian stingless bee Scaptotrigona depilis requires the brood cells-associated fungus Zygosaccharomyces sp. as steroid source for metamorphosis. Besides the presence of Zygosaccharomyces sp.

View Article and Find Full Text PDF

Social insects are frequently observed in symbiotic association with bacteria that produce antimicrobial natural products as a defense mechanism. There is a lack of studies on the microbiota associated with stingless bees and their antimicrobial compounds. To the best of our knowledge, this study is the first to report the isolation of Paenibacillus polymyxa ALLI-03-01 from the larval food of the stingless bee Melipona scutellaris.

View Article and Find Full Text PDF

A thorough study of the fermentation broth of three strains of Botrytis cinerea which were grown on a modified Czapek-Dox medium supplemented with 5 ppm copper sulphate, yielded five undescribed metabolites. These metabolites possessed a sesquiterpenoid (+)-4-epi-eremophil-9-ene carbon skeleton which was enantiomeric to that of the phytoalexin, capsidiol. The isolation of these metabolites when the fungus was stressed, suggests that they may be potential effectors used by B.

View Article and Find Full Text PDF

Microorganisms are found everywhere, and they are closely associated with plants. Because the establishment of any plant-microbe association involves chemical communication, understanding crosstalk processes is fundamental to defining the type of relationship. Although several metabolites from plants and microbes have been fully characterized, their roles in the chemical interplay between these partners are not well understood in most cases, and they require further investigation.

View Article and Find Full Text PDF

During an investigation of the chemistry of the endophytic actinobacterium Streptomyces albospinus RLe7, which was isolated from the roots of the Brazilian medicinal plant Lychnophora ericoides, three new natural products, (2R*,4S*)-2-((1'S*)-hydroxy-4'-methylpentyl)-4-(hydroxymethyl)butanolide (1), (3R*,4S*,5R*,6S*)-tetrahydro-4-hydroxy-3,5,6-trimethyl-2-pyranone (2), and 1-O-(phenylacetyl)glycerol (3), together with known secondary metabolites (S)-4-benzyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (4), (S)-4-isobutyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (5), and the diketopiperazines cyclo(l-Tyr-l-Pro) (6) and cyclo(l-Val-l-Pro) (7), were isolated. The role of isolated natural products in the interaction between S. albospinus RLe7 and the fungus Coniochaeta sp.

View Article and Find Full Text PDF

Endophytic actinobacteria from the Brazilian medicinal plant Lychnophora ericoides were isolated for the first time, and the biological potential of their secondary metabolites was evaluated. A phylogenic analysis of isolated actinobacteria was accomplished with 16S rRNA gene sequencing, and the predominance of the genus Streptomyces was observed. All strains were cultured on solid rice medium, and ethanol extracts were evaluated with antimicrobial and cytotoxic assays against cancer cell lines.

View Article and Find Full Text PDF

Background And Objectives: β-Lapachone is a drug candidate in phase II clinical trials for treatment of solid tumors. The therapeutic efficacy of β-lapachone is closely related to its metabolism, since this o-naphthoquinone produces cytotoxic effect after intracellular bioreduction by reactive oxygen species formation. The aim of this study was to produce β-lapachone human blood phase I metabolites to evaluate their cytotoxic activities.

View Article and Find Full Text PDF

The present work describes, for the first time, the simultaneous separation of oxcarbazepine (OXC) and its active metabolite 10-hydroxy-10,11-dihydrocarbamazepine (licarbazepine, Lic) by chiral CE. The developed method was employed to monitor the enantioselective biotransformation of OXC into its active metabolite by fungi. The electrophoretic separations were performed using 10 mmol/L of a Tris-phosphate buffer solution (pH 2.

View Article and Find Full Text PDF

Because piplartine (PPT) has demonstrated biological activities, such as cytotoxic, anxiolytic, antidepressant, antifungal and antiplatelet activities, this molecule is a relevant drug candidate. The metabolic fate of drug candidates is an essential requirement in assessing their safety and efficacy. Based on this requirement, the biotransformation of PPT by cytochrome P450 enzymes (CYP) was investigated for the first time.

View Article and Find Full Text PDF

We developed a capillary electrophoresis (CE) and dispersive liquid-liquid microextraction (DLLME) method to stereoselectively analyze hydroxyzine (HZ) and cetirizine (CTZ) in liquid culture media. The CE analyses were performed on an uncoated fused-silica capillary; 50mmolL(-1) sodium borate buffer (pH 9.0) containing 0.

View Article and Find Full Text PDF

Biotransformation of chemicals by microorganisms can be effective in increasing chemical diversity. Some fungi have been described to be useful for the biotransformation of sesquiterpene lactones. Nevertheless, in most cases, only minor or simple transformations of functional groups have been observed.

View Article and Find Full Text PDF

Due to the severity and high prevalence of allergic diseases, there is growing interest in the development of inhibitors of such conditions. 3-Arylcoumarin derivatives emerge as promising compounds for the treatment of allergic disorders, in particular due to their close structural similarity to flavonoids, whose anti-allergic activity has been extensively reported. The aim of this work was to perform a screening of a set of 3-arylcoumarins as potential inhibitors of mast cell degranulation, a key event for the development of allergic reactions.

View Article and Find Full Text PDF

A high-performance liquid chromatography (HPLC) method is presented for the simultaneous determination of midodrine and desglymidodrine (DMAE) in Czapek-Dox culture medium, to be used in biotransformation studies by fungi. The HPLC analysis was conducted using a Lichrospher 100 RP18 column, acetonitrile-40 mmol/L formic acid solution (60:40, v/v) as mobile phase, and ultraviolet detection at 290 nm. The sample preparation was conducted by liquid-liquid extraction using ethyl acetate as extractor solvent.

View Article and Find Full Text PDF

The lignan (-)-grandisin has shown important pharmacological activities, such as citotoxicity and antiangiogenic, antibacterial and trypanocidal activities. So, it has been considered as a potential drug candidate. In the early drug development process, drug metabolism is one of the main parameters that should be evaluated; therefore, the biotransformation of this lignan by rat liver microsomes was investigated for the first time.

View Article and Find Full Text PDF

The present work describes for the first time the use of SPME coupled to LC-MS/MS employing the polar organic mode in a stereoselective fungal biotransformation study to investigate the fungi ability to biotransform the drug risperidone into its chiral and active metabolite 9-hydroxyrisperidone (9-RispOH). The chromatographic separation was performed on a Chiralcel OJ-H column using methanol:ethanol (50:50, v/v) plus 0.2% triethylamine as the mobile phase at a flow rate of 0.

View Article and Find Full Text PDF

The biotransformation of the sesquiterpene lactone tagitinin C by the fungus Aspergillus terreus MT 5.3 yielded a rare derivative that was elucidated by spectrometric methods. The fungus led to the formation of a different product through an unusual epoxidation reaction between C4 and C5, formation of a C3,C10 ether bridge, and a methoxylation of the C1 of tagitinin C.

View Article and Find Full Text PDF

An high performance liquid chromatography (HPLC) method for the enantioselective determination of donepezil (DPZ), 5-O-desmethyl donepezil (5-ODD), and 6-O-desmethyl donepezil (6-ODD) in Czapek culture medium to be applied to biotransformation studies with fungi is described for the first time. The HPLC analysis was carried out using a Chiralpak AD-H column with hexane/ethanol/methanol (75:20:5, v/v/v) plus 0.3 % triethylamine as mobile phase and UV detection at 270 nm.

View Article and Find Full Text PDF

A high-performance liquid chromatographic method using polar organic mode was developed to analyze albendazole (ABZ), albendazole sulfone (ABZSO(2)) and the chiral and active metabolite albendazole sulfoxide (ABZSOX, ricobendazole) that was further applied in stereoselective fungal biotransformation studies. The chromatographic separation was performed on a Chiralpak AS column using acetonitrile:ethanol (97:3, v/v) plus 0.2% triethylamine and 0.

View Article and Find Full Text PDF