Chemical composition and antibacterial activity of 12 medicinal plant ethyl acetate extracts using LC-MS feature-based molecular networking

Untargeted Characterization and Biological Activity of Amazonian Aqueous Stem Bark Extracts by Liquid and Gas Chromatography-Mass Spectrometry

INTRODUCTION

Aqueous stem bark extracts of Aspidosperma rigidum Rusby, Couroupita guianensis Aubl., Monteverdia laevis (Reissek) Biral, and Protium sagotianum Marchand have been reported as traditional remedies in several countries of the Amazonian region. Despite previous research, further investigation to characterize secondary metabolites and the biological activity of extracts is needed to derive potential applications.

MATERIAL AND METHODS

Metabolic profiling was carried out using liquid and gas chromatography coupled with mass spectrometry (UHPLC-MS/MS and GC-MS). The chemical composition of the studied plants was further compared by principal component analysis (PCA). Additionally, chemical profiles were correlated with antimicrobial and toxicity activities, which suggested potential metabolites for future research.

RESULTS

We identified 16 and 32 compounds by UHPLC-MS/MS and GC-MS analysis, respectively. Antimicrobial activity was detected in three stem bark extracts. C. guianensis showed inhibition of all tested microorganisms, including antibiotic-resistant strains. Molecular networking approaches, in silico tools, and Pearson's correlation showed that antifungal compounds could be a terpene glycoside (r = 0.918) and/or a phenolic (r = 0.882) metabolite class.

CONCLUSION

This study highlights the use of the established procedure in exploring the metabolomes of these species, which could be a novel source of antimicrobial drug discovery. Coupling the observed biological potential with UHPLC-MS/MS data has also accelerated the tracing of their bioactive compounds. These findings update the state of the art regarding the chemical composition and biological activity of the plant extracts, defining potential new applications for the pharmaceutical applications.

Unraveling anti-aging mystery of green tea in C. elegans: Chemical truth and multiple mechanisms

Tea drinking impacts aging and aging-related diseases. However, knowledge of anti-aging molecules other than the major catechins in complex tea extracts remains limited. Here we used Caenorhabditis elegans to analyze the longevity effects of tea extracts and constituents comprehensively. We found that the hot water extract of green tea prolonged lifespan and heathspan. Further, the MeOH fraction prolonged lifespan significantly longer than other fractions. Correlation analysis between mass spectroscopic data and anti-aging activity suggests that ester-type catechins (ETCs) are the major anti-aging components, including 4 common ETCs, 6 phenylpropanoid-substituted ester-type catechins (PSECs), 5 cinnamoylated catechins (CCs), 7 ester-type flavoalkaloids (ETFs), and 4 cinnamoylated flavoalkaloids (CFs). CFs (200 μM) are the strongest anti-aging ETCs (with the longest 73% lifespan extension). Green tea hot water extracts and ETCs improved healthspan by enhancing stress resistance and reducing ROS accumulation. The mechanistic study suggests that they work by multiple pathways. Moreover, ETCs modulated gut microbial homeostasis, increased the content of short-chain fatty acids, and reduced fat content. Altogether, our study provides new evidence for the anti-aging benefits of green tea and insights into a deep understanding of the chemical truth and multi-target mechanism.

Inhibitory Effect of Phenethyl Isothiocyanate on the Adhesion and Biofilm Formation of Staphylococcus aureus and Application on Beef

This study aimed to explore the mechanism by which phenethyl isothiocyanate (PEITC) inhibited the adhesion and biofilm formation of Staphylococcus aureus (S. aureus). PEITC exhibited antimicrobial efficacy against S. aureus, demonstrating a minimum inhibition concentration (MIC) of 1 mmol/L. PEITC exerted its antibacterial effect by disrupting cell membrane integrity, and it decreased total adenosine triphosphate (ATP) production after 1 and 4 h treatment. PEITC at 0.5 mmol/L increased the level of intracellular reactive oxygen species (ROS) by 26.39% compared to control. The mature biofilm of S. aureus was destroyed by 86.4% after treatment with PEITC for 24 h. Adhesion tests revealed that PEITC at 0.5 mmol/L reduced 44.51% of the S. aureus that adhered to NCM460 cells. Furthermore, at the genetic level, PEITC significantly downregulated the related genes by 31.26% to 97.04%, including agrB, agrD, isdA, ebh, luxS, fnbA, and icaR. Moreover, PEITC markedly inhibited S. aureus proliferation in beef preserved at temperatures of 25 and 4 °C, respectively. In summary, the present study suggests that PEITC effectively inhibits the adhesion and biofilm formation of S. aureus by affecting the relevant genes of S. aureus and holds promise for microbial management in meat products.

Traditional Uses, Chemical Constituents and Pharmacological Activities of the Toona sinensis Plant

Toona sinensis (A. Juss.) Roem., which is widely distributed in China, is a homologous plant resource of medicine and food. The leaves, seeds, barks, buds and pericarps of T. sinensis can be used as medicine with traditional efficacy. Due to its extensive use in traditional medicine in the ancient world, the T. sinensis plant has significant development potential. In this review, 206 compounds, including triterpenoids (1-133), sesquiterpenoids (134-135), diterpenoids (136-142), sterols (143-147), phenols (148-167), flavonoids (168-186), phenylpropanoids (187-192) and others (193-206), are isolated from the T. sinensis plant. The mass spectrum cracking laws of representative compounds (64, 128, 129, 154-156, 175, 177, 179 and 183) are reviewed, which are conducive to the discovery of novel active substances. Modern pharmacological studies have shown that T. sinensis extracts and their compounds have antidiabetic, antidiabetic nephropathy, antioxidant, anti-inflammatory, antitumor, hepatoprotective, antiviral, antibacterial, immunopotentiation and other biological activities. The traditional uses, chemical constituents, compound cracking laws and pharmacological activities of different parts of T. sinensis are reviewed, laying the foundation for improving the development and utilization of its medicinal value.

Antibacterial and Toxic Activity of Geopropolis Extracts from Melipona subnitida (Ducke, 1910) (Hymenoptera: Apidae) and Scaptotrigona depilis (Moure, 1942) (Hymenoptera: Apidae)

Bacteria are associated with many infections that affect humans and present antibiotic resistance mechanisms, causing problems in health organisations and increased mortality rates. Therefore, it is necessary to find new antibacterial agents that can be used in the treatment of these microorganisms. Geopropolis is a natural product from stingless bees, formed by a mixture of plant resins, salivary secretions, wax and soil particles, the chemical composition of this natural product is diverse. Thus, this study aimed to evaluate antibacterial activity, antibiotic modulation and the toxicity of geopropolis extracts from the stingless bees, Melipona subnitida (Ducke, 1910) and Scaptotrigona depilis (Moure, 1942) against standard and multi-resistant Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa bacteria. Geopropolis samples were collected in a meliponary located in Camaragibe, Pernambuco, Brazil. To determine the Minimum Inhibitory Concentration (MIC) and antibiotic modulation we performed broth microdilution tests. Mortality tests were used to verify extract toxicity in the model Drosophila melanogaster. The microbiological tests showing that the M. subnitida extracts had better inhibitory effects compared to S. depilis, presenting direct antibacterial activity against standard and multi-resistant strains. The extracts potentialized antibiotic effects, suggesting possible synergy and did not present toxicity in the model used. The information obtained in this study highlights extracts as promising antibacterial agents and is the first study to evaluate bacterial activity in these extracts, in addition to verifying their modulating effects and determining toxicity in the model used.

Triterpenes and Pheophorbides from Camellia ptilosperma and Their Cytotoxicity, Photocytotoxicity, and Photodynamic Antibacterial Activity

Phytochemical investigation of the leaves of Camellia ptilosperma S. Y. Liang et Q. D. Chen led to the isolation of ten undescribed compounds, including six new triterpenes (1-6) and four new pheophorbide-related compounds (7-10). Meanwhile, the cytotoxic activity of the six triterpenes against six cancer cell lines was evaluated by MTT assay. Compound 2 showed potent cytotoxicity toward HepG2 cells with an IC50 value of 2.57 μM. Compounds 4 and 5 exhibited cytotoxicity against MDA-MB231 cells, with IC50 values of 11.31 and 5.52 μM, respectively. Additionally, the cytotoxicity of four new pheophorbides against these cancer cells was evaluated both in the presence and absence of light treatment. Compound 7 exhibited exceptional photocytotoxicity against Hela, MCF-7, and A549 cells, with IC50 values of 0.43 μM, 0.28 μM, and 0.92 μM, respectively. Compound 10 demonstrated significant photodynamic cytotoxic activity against BEL-7402 and HepG2 cells with IC50 values of 0.77 μM and 0.33 μM, respectively. The photodynamic antibacterial activity of 7-10 was also tested for S. aureus, E. coli, K. pneumoniae, and P. aeruginosa under direct illumination. Compounds 8 and 10 exhibited sensitivity to E. coli and demonstrated a photodynamic antibacterial effect, with a MIC value of 0.625 μM.

Aqueous Rosa damascena extract: Antibacterial activity and its role of adhesion to human epithelial cells in vitro

The current study aimed to investigate the inhibitory activity of aqueous extracts of different plant parts of Rosa damascena, represented by the whole rose, petals, and calyces, against clinical isolates of Staphylococcus spp., Escherichia coli, and Klebsiella pneumoniae, and the inhibition of the bacterial cell. The isolates were obtained from the advanced microbiology laboratory for postgraduate studies in the Department of Biology, Faculty of Education for Girls. They were isolated from urinary tract infections, which were subsequently subjected to diagnosis by the Vitek-2 compact system to confirm the type of bacteria as well as their sensitivity to antibiotics. The results obtained included Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus lentus, Staphylococcus saprophyticus, E. coli, and K. pneumoniae. A test was conducted to investigate the microbiological inhibitory activity of aqueous plant extracts of the whole rose, petals, and calyces using the well diffusion method and three concentrations of each aqueous extract (25, 50, and 100 mg/ml). The results showed the inhibitory ability of all concentrations of the different extracts toward Staphylococcus spp., and E. coli and K. pneumoniae bacteria were not affected by the different concentrations of the plant extract. The concentration of (100 mg/ml) for the aqueous extract was the most efficient in inhibiting growth compared to the other concentrations. The synergistic effect of three antibiotics was examined (Amoxicillin-clavulanate 10/20 μg, Piperacillin 100 μg, Trimethoprim-sulfamethoxazole 23.75/1.25 μg) and for all concentrations of the aqueous plant extract was investigated in both E. coli and K. pneumoniae, as it found a synergistic action between some of the antibiotics and extracts towards inhibiting the growth of the two bacterial isolates Resistance to the plant extract alone. Bacterial isolates showed a significant decrease in the rate of adhesion to epithelial cells isolated from urine samples of healthy women in the presence of the aqueous extract of whole rose, petals, and calyces at their three concentrations compared with the control treatment.

Multiple approaches to characterize and visualize the chemical composition of Sijunzi Decoction comprehensively

Sijunzi Decoction is composed of Ginseng Radix et Rhizoma, Atractylodes Macrocephalae Rhizoma, Poria, and Glycyrrhizae Radix Et Rhizoma Praeparata Cum Melle, and it is a classic formula for treating spleen deficiency syndrome in Chinese medicine. Clarifying the active substances is an effective way to develop Traditional Chinese medicine and innovative medicines. Carbohydrates, proteins, amino acids, saponins, flavonoids, phenolic acids, and inorganic elements in the decoction were analyzed by multiple approaches. A molecular network was also used for visualizing the ingredients in Sijunzi Decoction, and representative components were also quantified. The detected components accounted for 74.544% of the Sijunzi Decoction freeze-dried powder, including 41.751% crude polysaccharides, 17.826% sugars (degree of polymerization 1-2), 8.181% total saponins, 2.427% insoluble precipitates, 2.154% free amino acids, 1.177% total flavonoids, 0.546% total phenolic acids, and 0.483% inorganic elements. Molecular network and quantitative analysis used to characterize the chemical composition of Sijunzi Decoction. The present study systematically characterized the constituents of Sijunzi Decoction, revealed the composition ratio of each type of constituent, and provided a reference for study on the substance basis of other Chinese medicine.

Sequencing and analysis of the complete mitochondrial genomes of Toona sinensis and Toona ciliata reveal evolutionary features of Toona

BACKGROUND

Toona is a critical genus in the Meliaceae, and the plants of this group are an asset for both restorative and restorative purposes, the most flexible of which are Toona sinensis and Toona ciliata. To concentrate on the advancement of mitochondrial(Mt) genome variety in T.sinensis and T.ciliata, the Mt genomes of the two species were sequenced in high throughput independently, after de novo assembly and annotation to construct a Mt genome map for comparison in genome structure. Find their repetitive sequences and analyze them in comparison with the chloroplast genome, along with Maximum-likelihood(ML) phylogenetic analysis with 16 other relatives.

RESULTS

(1) T. sinensis and T.ciliata are both circular structures with lengths of 683482 bp and 68300 bp, respectively. They share a high degree of similarity in encoding genes and have AT preferences. All of them have the largest Phe concentration and are the most frequently used codons. (2) Both of their Mt genome are highly preserved in terms of structural and functional genes, while the main variability is reflected in the length of tRNA, the number of genes, and the value of RSCU. (3) T. siniensis and T. ciliata were detected to have 94 and 87 SSRs, respectively, of which mononucleotides accounted for the absolute proportion. Besides, the vast majority of their SSRs were found to be poly-A or poly-T. (4)10 and 11 migrating fragments were identified in the comparison with the chloroplast genome, respectively. (5) In the ML evolutionary tree, T.sinensis and T.ciliata clustered individually into a small branch with 100% support, reflecting two species of Toona are very similarly related to each other.

CONCLUSIONS

This research provides a basis for the exploitation of T.sinensis and T.ciliata in terms of medicinal, edible, and timber resources to avoid confusion; at the same time, it can explore the evolutionary relationship between the Toona and related species, which does not only have an important practical value, but also provides a theoretical basis for future hybrid breeding of forest trees, molecular markers, and evolutionary aspects of plants, which has great scientific significance.

Protocorm-like-body extract of Phalaenopsis aphrodite combats watermelon fruit blotch disease

Bacterial fruit blotch, caused by the seedborne gram-negative bacterium Acidovorax citrulli, is one of the most destructive bacterial diseases of cucurbits (gourds) worldwide. Despite its prevalence, effective and reliable means to control bacterial fruit blotch remain limited. Transcriptomic analyses of tissue culture-based regeneration processes have revealed that organogenesis-associated cellular reprogramming is often associated with upregulation of stress- and defense-responsive genes. Yet, there is limited evidence supporting the notion that the reprogrammed cellular metabolism of the regenerated tissued confers bona fide antimicrobial activity. Here, we explored the anti-bacterial activity of protocorm-like-bodies (PLBs) of Phalaenopsis aphrodite. Encouragingly, we found that the PLB extract was potent in slowing growth of A. citrulli, reducing the number of bacteria attached to watermelon seeds, and alleviating disease symptoms of watermelon seedlings caused by A. citrulli. Because the anti-bacterial activity can be fractionated chemically, we predict that reprogrammed cellular activity during the PLB regeneration process produces metabolites with antibacterial activity. In conclusion, our data demonstrated the antibacterial activity in developing PLBs and revealed the potential of using orchid PLBs to discover chemicals to control bacterial fruit blotch disease.