Patrícia Santana Barbosa Marinho

According to the World Health Organization (WHO), bacterial resistance is a critical global public health concern, highlighting the urgent need for novel antimicrobial agents. Tyrosol (1), a phenolic compound known for its broad spectrum of biological activities, served as the lead framework for the synthesis of three derivatives: 4‐(2‐acetoxyethyl)‐phenylacetate (2), 4‐(2‐(butyryloxy)‐ethyl)‐phenylbutyrate (3), and 4‐(2‐(benzoyloxy)‐ethyl)‐phenylbenzoate (4). Their structures were fully characterized by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). The antimicrobial activity of the compounds was evaluated against both Gram‐negative and Gram‐positive bacteria using the broth microdilution method. Among them, compound 2 exhibited the most potent activity, with minimum inhibitory concentrations (MICs) as low as 3.9 µg/mL. In addition, in silico ADME physicochemical properties were calculated using the SwissADME web tool. Compound 3 is also described for the first time in the literature.

This study investigated the effect of convective drying (40, 50, and 60 °C) on the drying kinetics and the physicochemical, phytochemical, and antimicrobial properties of Azadirachta indica leaves for food industry applications. The Midilli model best described the drying behavior. Increasing the temperature significantly reduced drying time and raised effective diffusivity, with an activation energy of 79.3 kJ mol⁻¹. Drying sharply reduced moisture content (78.54% to 5.84%) and water activity (< 0.40), ensuring material stability for storage. Essential oil yield remained constant (5.67%), but higher temperatures enhanced recovery per unit of dry mass. Chromatographic analyses revealed that drying temperature modulated volatile and phenolic profiles, affecting bioactive compound stability and transformation. The essential oil exhibited selective antimicrobial activity, particularly against Staphylococcus aureus, demonstrating strong potential against foodborne pathogens. Lower susceptibility in Gram-negative bacteria was attributed to structural barriers limiting hydrophobic compound action. Overall, temperature control is key to balancing process efficiency and bioactive preservation, confirming A. indica leaves as a viable source of natural antimicrobials and functional ingredients for food preservation.

Beneficial endophytic bacteria may confer advantages to their host plants and to the environment by pathogen control, while reducing pesticide use. The aim of this work was to determine the biochemical profile and antifungal activity of endophytic bacteria from black pepper roots against Fusarium solani f. sp. piperis , F. oxysporum , and Colletotrichum gloeosporioides , which cause fusariosis and anthracnose in black pepper. One hundred and sixty‐four endophyte bacteria strains isolated from black pepper roots were tested in vitro against three phytopathogenic fungi. Seven selected antagonistic strains were identified at the genus level by sequencing the 16S region of the ribosomal RNA. In addition, the production of lytic enzymes and siderophores was evaluated that may be related to the biocontrol of pathogenic microorganisms. The effect of ethyl acetate and ethanolic extracts of antagonistic strains on the germination of pathogen spores was evaluated. Strains C5.4, C5.9, T1.5, T4.1, T4.7, T6.2, and T6.4 showed antifungal activity with inhibition ranging from 30.27% to 61.42%, and were identified as species of the genus Burkholderia . The biochemical profile showed that strains produced lipase, esterase, protease, and siderophores, which may be related to their antifungal activity. The best results of antifungal activity were shown by the ethyl acetate extracts of strains C5.4, C5.9, T4.7, T6.2, T6.4, and T4.1, with percentages ranging from 4.71% to 51.89%. This study demonstrated that endophytic bacteria from black pepper have potential for the biocontrol of fungal diseases and can be further investigated to obtain a formulation for the control of pathogenic microorganisms associated with this crop.

Araçá (Psidium guineense Sw.) fruits were collected in Belém and freeze-dried for 72 h. An ultrasound-assisted extraction method was optimized using a central composite design (23) to evaluate the effects of ethanol concentration, solid-liquid ratio (SLR), and extraction time on total phenolics content (TPC) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) precentage of radical inhibition). A predictive polynomial model established at a 95% confidence level indicated optimal parameters of 25% ethanol, a 1:5 SLR, and a 10-min extraction time, yielding 304.6 ± 7.7 mg GAE g-1 of TPC and 59.5 ± 1.7% DPPH inhibition. The optimized extract also inhibited β-carotene lipid peroxidation with an IC50 value (half maximal inhibitory concentration) of 20.9 µg mL-1 and presented a sun protection factor of 16.0 ± 1.0. It contained substantial amounts of total flavonoids and carotenoids: 309.2 ± 17.7 mg QE g-1 and 108.2 ± 11.1 µg g-1, respectively. Liquid chromatography-electrospray ionization ion trap mass spectrometry (LC-MS/MS) analysis annotated key bioactive compounds, including quinic acid, ellagic acid, valoneic acid dilactone, and caffeoyl-quinic acid, these compounds are responsible for the antioxidant potential. Additionally, the extract demonstrated a bactericidal effect against Staphylococcus aureus, highlighting its potential use as an antiseptic. The bioprospecting of extract supports the potential for new industrial applications of P. guineense fruits, particularly within the cosmetic sector.

The objective of this work was to investigate three endophytic bacterial strains as to their ability to promote the growth and rooting of black pepper stem cuttings, as well as to determine the mechanisms involved in the promoting activity through molecular methods. The strains were identified by 16S sequencing as belonging to the genera Bacillus, Priestia, and Lysinibacillus. They were characterized for the production of indoleacetic acid (IAA), phosphate solubilization, and siderophore production. In two assays, the roots of the cuttings were immersed in bacterial suspensions to evaluate growth promotion through plant height, stem diameter, and root and shoot dry mass. The Bacillus sp. C1.4 and Priestia sp. T2.2 strains were able to produce siderophores, whereas Priestia sp. T2.2 and Lysinibacillus sp. C5.11 produced IAA. In addition, Priestia sp. T2.2 significantly increased plant height and dry mass, whereas Lysinibacillus sp. C5.11 significantly increased root dry mass. Therefore, Priestia sp. T2.2 and Lysinibacillus sp. C5.11 are able to promote the growth and rooting of black pepper stem cuttings, respectively. This growth promotion is linked directly to the production of IAA and siderophores.

Turmeric is a spice that has gained significant popularity in global cuisine. Beyond its culinary applications, it possesses significant medicinal properties, including antioxidant, anti-inflammatory, and antibacterial properties, which are attributed to its majority compound, curcumin. In this study, we synthesized three curcuminoid derivatives via the Claisen–Schmidt method (1E,4E)-1-(2-methoxy-phenyl)-5-(3-methoxy-phenyl)-pent-1,4-dien-3-one (2a), (1E,4E)-1-(2-methoxy-phenyl)-5-(3,4,5-trimethoxy-phenyl)-pent-1,4-dien-3-one (2b), and (1E,4E)-5-phenyl-1-(2-methoxy-phenyl)-pent-1,4-dien-3-one (2c). The synthetic compounds were hydrogenated in the olefinic double bond (CH=CH) by biotransformation catalyzed by the fungus Exserohilum rostratum given (CH₂-CH₂) 3a, 3b, and 3c. All compounds were identified by NMR and MS. The compounds were evaluated for their antibacterial properties against Gram-positive and Gram-negative bacteria, with the results indicating good activity, highlighting that the bioreduction from 2a to 3a led to an improvement of up to eight times in the observed activity against S. typhimurium of 250 to 31.25 µg/mL. Additionally, compounds 2a, 2b, 3a, and 3b are not previously documented in the literature.

The search for bioactive compounds for the treatment of several diseases has led to the study of endophytic fungi. Neoplastic diseases are among the most significant health concerns due to their high mortality rate, and there is a dearth of efficacious pharmaceutical agents for the treatment of cancer. Gastric cancer is one of the most aggressive forms of cancer and is among those with the highest mortality rates in Brazil. Accordingly, the objective of this study was to identify compounds with cytotoxic activity from the mangrove-derived endophytic fungus Trichoderma sp. Isolation of the chemical compounds was conducted using chromatographic methods, while structural elucidation was achieved through the application of spectroscopic (NMR and UV) and spectrometric (MS) techniques. The fungus Trichoderma sp. was found to produce five distinct koninginins (A, B, C, E, and J). The organic phases of the extracts and isolated compounds were evaluated for their antimicrobial and cytotoxic potentials, respectively, through microdilution testing and the MTT method. In the cytotoxicity assay, both the AF extract and koninginin A demonstrated favorable outcomes, indicating their potential as promising anticancer therapeutic agents.

As principais doenças do maracujazeiro são causadas por microorganismos. O fungo Rhizoctonia solani Kuhn é um fungo fitopatogênico e na cultura do maracujá, este fungo é responsável pela queima foliar, causando sérios prejuízos ao seu cultivo. O presente trabalho teve como objetivo buscar extratos bioativos de fungos endofíticos de noni (Morinda citrifolia) contra Rhizoctonia solani Kuhn. Foram isolados 82 fungos endofíticos das folhas, frutos, caule e raiz de M. citrifolia e separados em 11 grupos, onde de um fungo de cada grupo foi obtidos seu extrato. No ensaio in vitro os extratos demonstraram boa atividade antifúngica. Os extratos mais ativos NF12, NF17, NR7 e NFrS2 foram analisados por HPLC o que evidenciou a presença de compostos das classes das azafilonas, terpenos, tricotecenos e compostos fenólicos como constituintes químicos majoritários nos extratos. Os dados demostram que extratos de fungos endofíticos podem representar uma nova abordagem para os problemas relacionados ao combate as doenças do maracujazeiro.

The search for bioactive compounds for the treatment of several diseases has led to the study of endophytic fungi. Neoplastic diseases are among the most significant health concerns due to their high mortality rate, and there is a dearth of efficacious pharmaceutical agents for the treatment of cancer. Gastric cancer is one of the most aggressive forms of cancer and is among those with the highest mortality rates in Brazil. Accordingly, the objective of the present study was to identify compounds with cytotoxic activity from the mangrove-derived endophytic fungus Trichoderma sp. Isolation of the chemical compounds was conducted using chromatographic methods, while structural elucidation was achieved through the application of spectroscopic (NMR and UV) and spectrometric (MS) techniques. The fungus Trichoderma sp. was found to produce five distinct koninginins (A, B, C, E, and J). The organic phases of the extracts and isolated compounds were evaluated for their antimicrobial and cytotoxic potentials, respectively, through microdilution testing and the MTT method. In the cytotoxicity assay, both the AF extract and koninginin A demonstrated favorable outcomes, indicating their potential as promising anticancer therapeutic agents.