Phytochemistry, antifungal and antioxidant activity, and cytotoxicity of byrsonima gardneriana (A. Juss) extract

Identification of novel natural anti-browning agents based on phenotypic and metabolites differences in potato cultivars

This study aimed to elucidate the changes of browning-related metabolite in fresh-cut potato and to identify anti-browning agents. Metabolomics and weighted correlation network analysis (WGCNA) were used to identify metabolites and correlate them with potato browning traits. A total of 79 browning trait-positive-related metabolites and 19 browning trait-negative-related metabolites were obtained from four key modules via WGCNA. The accumulation of metabolites with rich reducing groups and acidic groups were found to enhance anti-browning activity in potatoes. Among these metabolites, only L-pyroglutamic acid (L-PA) and ascorbic acid had variable importance for the projection (VIP) values greater than 1.5. In addition, it was found that L-PA inhibited polyphenol oxidase (PPO) activity by lowering pH and interacting with amino acid residues of PPO. L-PA also inhibited the growth of microorganisms in fresh-cut potato. Our results show that L-AP is an effective novel anti-browning agent with antibacterial activity.

Comprehensive Bio-Screening of Phytochemistry and Biological Capacity of Oregano (Origanum vulgare) and Salvia triloba Extracts against Oral Cariogenic and Food-Origin Pathogenic Bacteria

This study utilized phytochemical screening to conduct the qualitative analysis of plant extracts, aiming to identify various classes of secondary metabolites. Moreover, the antibacterial activity of different types of Oregano vulgare and Salvia triloba extracts was determined. To achieve the aim of this study, aqueous, ethanolic, and enzymatic extracts were prepared and screened for phytochemical capacity and antioxidant activities. The determination of the antibacterial activity included phenotypic screening of antibiotic susceptibility pattern of oral and food pathogenic bacterial strains, determination of the minimum inhibitory concentration and minimum bactericidal concentration-via microdilution broth test and in vitro valuation of antibacterial efficacies-of the anti-biofilm properties of the studied herbal extractions. Results: Our study evaluated the phytochemical composition and the antioxidant, antibacterial, and anti-biofilm properties of O. vulgare and S. triloba extracts. The analyzed samples contained bioactive compounds, such as phenolics and flavonoids, contributing to the observed strong antioxidant effect. Furthermore, they exhibited notable activity against oral biofilm formation and demonstrated significant antibacterial efficacy against dental caries' microorganisms as well as food pathogens. Despite methodological variations, all extracts showed significant antioxidant capacity and promising antibacterial activity against various pathogens, including resistant strains, while also inhibiting biofilm formation. Although limited to two plant species and facing methodological constraints, this study lays the groundwork for future research, indicating the therapeutic potential of O. vulgare and S. triloba extracts. Further exploration is needed to report on underlying mechanisms and validate efficacy through clinical trials.

Epifriedelanol is the key compound to antibacterial effects of extracts of Synadenium glaucescens (Pax) against medically important bacteria

Introduction

Synadenium glaucescens has been used for the treatment of bacterial infections in many parts of the world. We investigated the antibacterial and cytotoxicity activities of secondary metabolites of this plant.

Methods

Hexane, dichloromethane, methanol, and water were used as extraction solvents. The extract of the root bark was fractionated with ethyl acetate and methanol. The isolation of compounds from root barks, leaves and stem wood extracts were carried out using column chromatography. Antibacterial activities were characterized based on growth curves, killing curves and MIC determinations. Haemolytic effect towards sheep red blood cells (RBCs) was analysed with spectrophotometer at the wavelength of 540nm.

Results and Discussion

Extracts from whole root and root bark showed strong activity against Staphylococcus aureus, and Streptococci and Enterococci species, and moderate to weak activity against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella species, Shigella sonnei and Yersinia enterocolitica. Staphylococcus aureus was the most susceptible, and E. coli and Klebsiella pneumonia were the least susceptible ones. Likewise, extracts, fractions, sub-fractions and epifriedelanol demonstrated bacteriostatic activity against S. aureus. The haemolytic activity of the extracts, fractions, sub-fractions and epifriedelanol was significantly low compared to the positive control, hydrogen peroxide. But extract from leaves showed high haemolytic effects at the concentrations of 500 μg/mL and 1000 μg/mL. Thus, extracts of S. glaucescens have antibacterial activity against several Gram-positive bacteria including Methicillin Resistant S. aureus with low haemolytic activity. At high concentrations, the extracts from leaves have toxicity risk. More studies for the active compounds are required for biological testing.

Galloylquinic acid derivatives from Byrsonima fagifolia leaf extract and potential antifungal activity

ETHNOPHARMACOLOGICAL RELEVANCE

Byrsonima fagifolia Niedenzu (Malpighiaceae) and other Byrsonima species are popularly employed in Brazilian traditional medicine in the form of preparations as cicatrizing, anti-inflammatory, and antimicrobial.

AIM OF THE STUDY

To characterize the phytochemical profile of the hydromethanolic extract obtained from B. fagifolia leaves (BF extract) and to evaluate the toxicity and the antifungal activity.

MATERIALS AND METHODS

The compounds from BF extract were isolated by HPLC and the structures were elucidated based on extensive analyses of 1D and 2D NMR spectra (HMQC, HMBC and COSY) data. The antifungal effect was determined by the broth microdilution method and the toxicity was evaluated on erythrocytes from sheep's blood and Galleria mellonella larvae.

RESULTS

Phytochemical investigation of the BF extract led to the isolation and characterization of pyrogallol, n-butyl gallate, 3,4-di-O-galloylquinic acid, 3,5-di-O-galloylquinic acid, 3,4,5-tri-O-galloylquinic acid, and 1,3,4,5-tetra-O-galloylquinic acid. The BF extract showed high content of galloylquinic acid derivatives reaching more than twenty-times the quercetin derivatives content, according to the quantification by HPLC. These galloylquinic acid derivatives, obtained during this study, and quercetin derivatives, previously isolated, were submitted to the antifungal assays. The BF extract inhibited yeast growth mainly against Cryptococcus spp., at concentrations of 1-16 μg/mL, comparable to isolated compounds galloylquinic acid derivatives. However, the quercetin derivatives as well as quinic acid, gallic acid, and methyl gallate showed lower antifungal effect compared with galloylquinic derivatives. In addition, the BF extract had no hemolytic effect and no toxicity on G. mellonella.

CONCLUSION

The phytochemical analysis revealed that galloylquinic acid derivatives are the major compounds in the leaves of B. fagifolia and they are associated to anti-cryptococcal activity and presented reduced toxicity.