Antimicrobial properties of prunin, a citric flavanone glucoside, and its prunin 6″-O-lauroyl ester

Decoding the biochemical dialogue: metabolomic insights into soybean defense strategies against diverse pathogens

Soybean, a crucial global leguminous crop, confronts persistent threats from diverse pathogens, exerting a profound impact on global yields. While genetic dimensions of soybean-pathogen interactions have garnered attention, the intricate biochemical responses remain poorly elucidated. In this study, we applied targeted and untargeted liquid chromatography coupled to mass spectrometry (LC-MS) metabolite profiling to dissect the complex interplay between soybeans and five distinct pathogens. Our analysis uncovered 627 idMS/MS spectra, leading to the identification of four main modules, encompassing flavonoids, isoflavonoids, triterpenoids, and amino acids and peptides, alongside other compounds such as phenolics. Profound shifts were observed in both primary and secondary metabolism in response to pathogenic infections. Particularly notable were the bidirectional changes in total flavonoids across diverse pathogenic inoculations, while triterpenoids exhibited a general declining trend. Noteworthy among the highly inducible total flavonoids were known representative anti-pathogen compounds (glyceollin I), backbone forms of isoflavonoids (daidzein, genistein, glycitein, formononetin), and newly purified compounds in this study (prunin). Subsequently, we delved into the biological roles of these five compounds, validating their diverse functions against pathogens: prunin significantly inhibited the vegetative growth and virulence of Phytophthora sojae; genistein exhibited a pronounced inhibitory effect on the vegetative growth and virulence of Phomopsis longicolla; daidzein and formononetin displayed significant repressive effects on the virulence of P. longicolla. This study underscores the potent utility of metabolomic tools, providing in-depth insights into plant-pathogen interactions from a biochemical perspective. The findings not only contribute to plant pathology but also offer strategic pathways for bolstering plant resistance against diseases on a broader scale.

Prunin Laurate Derived from Natural Substances Shows Antibacterial Activity against the Periodontal Pathogen Porphyromonas gingivalis

Periodontal disease is an inflammatory disease caused by infection with periodontopathogenic bacteria. Oral care is essential to prevent and control periodontal disease, which affects oral and systemic health. However, many oral hygiene products currently on the market were developed as disinfectants, and their intense irritation makes their use difficult for young children and older people. This study investigated the antibacterial effects of prunin laurate (Pru-C12) and its analogs on periodontopathogenic bacteria, Porphyromonas gingivalis (P. gingivalis). Pru-C12 and its analogs inhibited in vitro bacterial growth at more than 10 μM and biofilm formation at 50 µM. Among its analogs, only Pru-C12 showed no cytotoxicity at 100 µM. Three of the most potent inhibitors also inhibited the formation of biofilms. Furthermore, Pru-C12 inhibited alveolar bone resorption in a mouse experimental periodontitis model by P. gingivalis infection. These findings may be helpful in the development of oral hygiene products for the prevention and control of periodontal disease and related disorders.

Antibacterial Sesquiterpene Lactones from Kaunia lasiophthalma

Phytochemical study of the species Kaunia lasiophthalma enabled the isolation of three undescribed and three known guaianolide-type sesquiterpene lactones, and one new benzofuran. The bioguided fractionation methodology was successful in detecting antimicrobial metabolites against Staphylococcus aureus strains and permitted the description of undescribed guaianolide-type sesquiterpene lactones with substitution patterns matching all those described in the Oxylobinae subtribe.

Modelling and targeting mitochondrial protein tyrosine phosphatase 1: a computational approach

The present research scintillates on the homology modelling of rat mitochondrial protein tyrosine phosphatase 1 (PTPMT1) and targeting its activity using flavonoids through a computational docking approach. PTPMT1 is a dual-specificity phosphatase responsible for protein phosphorylation and plays a vital role in the metabolism of cardiolipin biosynthesis, insulin regulation, etc. The inhibition of PTPMT1 has also shown enhanced insulin levels. The three-dimensional structure of the protein is not yet known. The homology modelling was performed using SWISS-MODEL and Geno3D webservers to compare the efficiencies. The PROCHECK for protein modelled using SWISS-MODEL showed 91.6% of amino acids in the most favoured region, 0.7% residues in the disallowed region that was found to be significant compared to the model built using Geno3D. 210 common flavonoids were docked in the modelled protein using the AutoDock 4.2.6 along with a control drug alexidine dihydrochloride. Our results show promising candidates that bind protein tyrosine phosphatase 1, including, prunin (- 8.66 kcal/mol); oroxindin (- 8.56 kcal/mol); luteolin 7-rutinoside (- 8.47 kcal/mol); 3(2H)-isoflavenes (- 8.36 kcal/mol); nicotiflorin (- 8.29 kcal/mol), ranked top in the docking experiments. We predicted the pharmacokinetic and Lipinski properties of the top ten compounds with the lowest binding energies. To further validate the stability of the modelled protein and docked complexes molecular dynamics simulations were performed using Desmond, Schrodinger for 150 ns in conjunction with MM-GBSA. Thus, flavonoids could act as potential inhibitors of PTPMT1, and further, in-vitro and in-vivo studies are essential to complete the drug development process.

Potential development of non-synthetic food additives from orange processing by-products—a review

Citrus is the largest fruit crop worldwide. Meanwhile, oranges account for 60 per cent of the total, with their main application in juice production. During orange juice production, only about 50 per cent of the fresh orange weight is transformed into juice, with the remaining 50 per cent comprised of residue (peel, pulp, seeds, orange leaves and whole orange fruits that do not reach the quality requirements). With the resulting tons of orange by-products, there has been an initiative to research possible ways to reutilize and revalorize citrus waste. Orange pomace, the by-product from juicing process, is currently used to extract the essential oils for fragrance and flavor, and a majority of the waste is used as cattle feed; however, these applications do not account for all of the waste or capture all of its potential value. Meanwhile, these by-products are put into landfills at the owner’s expense, and contribute to global warming through carbon emissions. On the other hand, orange by-products still contain many useful nutraceutical components, such as dietary fiber and phytochemicals, which could be utilized for value-added ingredients and new product development. Some research approaches in this area include the production of organic fertilizers and biofuels, or the extraction of essential oils, pectins, and antioxidant compounds. There is little information in the literature and in the food industry in terms of utilizing the orange pomace directly or with some simple treatments. Orange pomace may be used for food product development as a ‘clean-label’, non-synthetic preservative, which rationalizes this review.

Design, Synthesis and Antiproliferative Evaluation of Novel 1,2,4-Triazole/Schiff Base Hybrids with EGFR and B-RAF Inhibitory Activities

Background:

1,2,4-triazoles possess a broad spectrum of biological activities such as analgesic, antimicrobial, antitubercular, anti-inflammatory and antineoplastic activities. This heterocycle and their derivatives were included into a wide variety of therapeutically interesting drugs. Hence, it is of great interest to explore new 1,2,4-triazoles as cytotoxic agents targeting EGFR, B-Raf kinases.

Methods:

The final compounds 9a-b, 10a-b, 11a-b, 12a-b, 13a-b and 14a-f were prepared by refluxing a mixture of triazole 3a-b and 7a-d with the corresponding benzaldehyde derivatives 8a-d in absolute ethanol to afford the target final compounds in good yields. The newly synthesized triazole-containing compounds were assessed according to standard protocols for their in vitro antiproliferative activity against four human cancer cell lines including human pancreas cancer cell line (Panc-1), pancreatic carcinoma cells (PaCa-2), colon cancer cells (HT-29) and lung cancer cells (H-460) using the propidium iodide (PI) fluorescence assay. Compounds 9a and 13a were evaluated against EGFR, B-Raf and Tubulin anticancer targets.

Results:

Compounds 9a, 9b, 10a, 11a, 12a, 13a and 13b showed remarkable antiproliferative activity against the tested cell lines with IC50 range of 1.3-5.9µM. Compounds 9a and 13a with the least IC50 values in the anticancer screening assay were tested against three known anticancer targets including EGFR, B-Raf kinase and Tubulin. The results revealed that compound 13a showed the highest potency against B-Raf and EGFR kinases with IC50 = 0.7 and 1.9 µM, respectively.

Conclusion:

1,2,4-triazoles reported herein are potent EGFR, B-Raf inhibitors. These lead compounds will be subjected to more detailed mechanistic studies.

Association of polyphenols from oranges and apples with specific intestinal microorganisms in systemic lupus erythematosus patients

Our group has recently shown the existence of a gut microbial dysbiosis in systemic lupus erythematosus (SLE), supporting previous evidence involving intestinal bacteria in the initiation and amplification of autoimmune diseases. While several studies have addressed the use of dietary fibres to modify intestinal microbiota, information about other correlated components, such as polyphenols, is scarce. The aim of this work was to identify dietary components able to influence this altered microbiota in 20 SLE women and 20 age-matched controls. Food intake was recorded by means of a food frequency questionnaire. The intake of fibres was calculated from Marlett tables, and Phenol-Explorer was used for polyphenol consumption. Results showed positive associations between flavone intake and Blautia, flavanones and Lactobacillus, and dihydrochalcones and Bifidobacterium in the SLE group. Regarding the controls, dihydroflavonols were directly associated with Faecalibacterium, whereas flavonol intake was inversely associated with Bifidobacterium. From the food sources of these polyphenols related to microbiota, orange intake was directly associated with Lactobacillus and apple with Bifidobacterium in SLE, whilst red wine was the best contributor to Faecalibacterium variation. The association between common foods and particular microbial genera, reported to be decreased in SLE, could be of great importance for these patients.

Pilot study of diet and microbiota: interactive associations of fibers and polyphenols with human intestinal bacteria

Several studies have addressed the use of dietary fibers in the modulation of intestinal microbiota; however, information about other highly correlated components in foods, such as polyphenols, is scarce. The aim of this work was to explore the association between the intake of fibers and polyphenols from a regular diet and fecal microbiota composition in 38 healthy adults. Food intake was recorded using an annual food frequency questionnaire (FFQ). Quantification of microbial populations in feces was performed by quantitative PCR. A negative association was found between the intake of pectins and flavanones from oranges and the levels of Blautia coccoides and Clostridium leptum. By contrast, white bread, providing hemicellulose and resistant starch, was directly associated with Lactobacillus. Because some effects on intestinal microbiota attributed to isolated fibers or polyphenols might be modified by other components present in the same food, future research should be focused on diet rather than individual compounds.

Biotransformation of puerarin into puerarin-6″-O-phosphate by Bacillus cereus

The biotransformation of puerarin catalyzed by Bacillus cereus NT02 was studied. A primary screening was carried out using 307 strains of bacteria isolated from soil which were able to grow in the presence of puerarin. Strain NT02, identified as B. cereus, was able to convert puerarin into puerarin-6″-O-phosphate. Under the optimum conditions, resting cells of B. cereus NT02 converted 27% of added 0.4 g/l puerarin into puerarin-6″-O-phosphate that was characterized by MS, 13C NMR, 31P NMR. The activity of puerarin-6″-O-phosphate was 25 times higher than that of puerarin in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging system. The water solubility of puerarin-6″-O-phosphate was 85.4 times higher than that of puerarin.

Antibacterial activity of naringin derivatives against pathogenic strains

AIMS

To study the antimicrobial activity of naringin (NAR), a flavonoid extracted from citrus industry waste, and NAR derivatives [naringenin (NGE), prunin and alkyl prunin esters] against pathogenic bacteria such as L. monocytogenes, E. coli O157:H7 and S. aureus. The relationship between the structure of the chemical compounds and their antagonistic effect was also analysed.

METHODS AND RESULTS

The agar dilution technique and direct contact assaying were applied. NGE, prunin and NAR showed no antimicrobial activity at a concentration of 0.25 mmol l(-1). Similarly, fatty acids with a chain length between C2 and C18 showed no antimicrobial activity at the same concentration. However, prunin-6″-O-acyl esters presented high antibacterial activity, mainly against Gram-positive strains. This activity increased with increasing chain length (up to 10-12 carbon atoms). Alkyl prunin esters with 10-12 carbon atoms diminished viability of L. monocytogenes by about 3 log orders and S. aureus by 6 log orders after 2 h of contact at 37°C and at a concentration of 0.25 mmol l(-1). The compounds examined were not effective against any of the Gram-negative strains assayed, even at the highest concentration.

CONCLUSIONS

Addition of sugars to the aglycone did not enhance its antimicrobial activity. Attachment of a saturated aliphatic chain with 10-12 carbon atoms to the A ring of the flavonoid (or to sugars attached to this ring), seems to be the most promising modification. In conclusion, alkyl prunin esters with a chain length of C10-C12 have promising features as antimicrobial agents because of their high antilisterial and antistaphylococcal activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows that it is possible to obtain NAR derivatives with important antimicrobial activity, especially against Gram-positive pathogenic bacteria. It also provides guidelines on the structural modifications in similar molecules to enhance the antimicrobial activity.