Chemical profile and phytotoxic action of Onopordum acanthium essential oil

Overview of Ethnobotanical-Pharmacological Studies Carried Out on Medicinal Plants from the Serra da Estrela Natural Park: Focus on Their Antidiabetic Potential

The Serra da Estrela Natural Park (NPSE) in Portugal stands out as a well-preserved region abundant in medicinal plants, particularly known for their pharmaceutical applications in diabetes prevention and treatment. This comprehensive review explores these plants' botanical diversity, traditional uses, pharmacological applications, and chemical composition. The NPSE boast a rich diversity with 138 medicinal plants across 55 families identified as traditionally and pharmacologically used against diabetes globally. Notably, the Asteraceae and Lamiaceae families are prevalent in antidiabetic applications. In vitro studies have revealed their significant inhibition of carbohydrate-metabolizing enzymes, and certain plant co-products regulate genes involved in carbohydrate metabolism and insulin secretion. In vivo trials have demonstrated antidiabetic effects, including glycaemia regulation, insulin secretion, antioxidant activity, and lipid profile modulation. Medicinal plants in NPSE exhibit various activities beyond antidiabetic, such as antioxidant, anti-inflammatory, antibacterial, anti-cancer, and more. Chemical analyses have identified over fifty compounds like phenolic acids, flavonoids, terpenoids, and polysaccharides responsible for their efficacy against diabetes. These findings underscore the potential of NPSE medicinal plants as antidiabetic candidates, urging further research to develop effective plant-based antidiabetic drugs, beverages, and supplements.

Study of a Mexican isolate of Arthrobotrys musiformis (Orbiliales): Predatory behavior and nematocidal activity of liquid culture filtrates against Haemonchus contortus (Trichostrongylidae), protein profile and myco-constituent groups

A Mexican isolate of the nematophagous fungus Arthrobotrys musiformis was obtained from a soil sample from the Chapultepec ecological reserve zone, in Cuernavaca, Morelos, Mexico. This isolate demonstrated an important predatory activity (74.9%) against the parasitic nematode Haemonchus contortus (L3) and its fungal liquid culture filtrates (LCF) grown in two media showed the following highest nematocidal activities (NA): In Czapek-DoxBroth (CzDoxB) 80.66% and potato-dextrose broth (PDB) 49.84%. Additionally, two major compounds derived from carboxylic acids and two derivates from alkane group were identified by GC-MS. These compounds have been associated to many biological activities. On the other hand, the protein profile analysis by SDS-electrophoresis followed by a zymogram revealed a 10 kDa protein with protease activity. This study provides important information for future experiments focused to explore the potential use of this protein as well as the identified bioactive compounds presents in the LCF as potential candidates against sheep haemonchosis.

Flavor evolution of normal- and low-fat Chinese sausage during natural fermentation

This work compared the flavor evolution of normal-fat (NF) with that of low-fat (LF) Chinese sausage during natural fermentation. Higher degree of lipid oxidation occurred in NF sausages, resulting in its faster formation of stable volatile profiles. Faster formation of esters occurred in NF sausage in the initial 10 days, whereas prolonged fermentation reduced the level of ethyl lactate-M, ethyl heptanoate, ethyl hexanoate-D and ethyl pentanoate-D. Gradual reduction of alcohols was observed in both groups, and surge in aldehydes occurred in LF samples during day 20-30 period. Faster formation of taste characteristics and larger amount of 2-methylfuran as well as 2,3-dimethylpyrazine were found in LF sausages, since more free amino acids were liberated in LF sausages. Umami and aftertaste tastes formed in the first 20 days, whereas prolonged fermentation reduced these favorable taste. These results highlight that the choice of proper fermentation duration should largely depend on the fat content in Chinese sausages.

Phytotoxic Interference of Culture Filtrates of Endophytic Bacteria Associated with Nerium oleander Leaf Against Seed Germination of the Invasive Noxious Weed Cenchrus echinatus

Weeds cause destructive agricultural losses, so weed control is an urgent challenge facing agriculture. The extensive use of synthetic chemical herbicides has detrimental environmental impacts and promotes the emergence of resistant species. Therefore, in this study we tried to find a new natural weed control that can ensure biosafety and eco-sustainability. The phytotoxic potential of culture filtrates of the endophytes Bacillus inaquosorum NL1 and Bacillus safensis NL2 isolated from Nerium oleander leaf against the invasive harmful weed species Cenchrus echinatus was evaluated. Culture filtrates of both bacterial species exhibited potent phytotoxic activity, which resulted in 100% germination inhibition of C. echinatus. The chemical analysis of culture filtrates revealed high contents of total phenolics and n-alkanes that have phytotoxic effects against seed germination. According to the findings of this study the endophytic bacteria associated with N. oleander leaf can be used in the future to develop a sustainable bio-herbicide formulation.

Juniperus horizontalis Moench: Chemical Composition, Herbicidal and Insecticidal Activities of Its Essential Oil and of Its Main Component, Sabinene

The composition, herbicidal, larvicidal, and toxic activities of Juniperus horizontalis Moench essential oil and sabinene, its main component, were evaluated. The seed germination percentage and root length of eight different plant species (crops and weeds) were measured for in vitro herbicidal activity tests. Different doses (100, 50, 10, 5, 1, 0.5 µg/mL) of the samples were applied to seeds for 120 h. The same doses were applied to test the toxicity of the samples on Tubifex tubifex (sludge worm) and Chironomus aprilinus (blood worm). Four doses (435, 652.5, 870, and 1740) of samples were in a larvicidal test on Tenebrio molitor L. (mealworm), and bioassays were checked after 24 and 48 h. The analysis of the oil allowed for the identification of dominant components as sabinene (38.7%), α-pinene (10.0%), elemol (8.6%), γ-terpinene (8.3%), limonene (7.8%) and α-thujene (5.3%). The results showed that the effect of oil on root length inhibition was significant in all crop species. The doses which affected root growth were not toxic to Tubifex tubifex and Chironomus aprilinus. Finally, the obtained results in the larvicidal bioassay indicate that the potential of J. horizontalis in yellow mealworm survivorship limitation can be a starting point for future research.

Phytotoxic, insecticidal, and antimicrobial activities of Ajania tibetica essential oil

The chemical profile of Ajania tibetica essential oil (EO) and its phytotoxic, insecticidal, and antimicrobial activities were assessed. Monoterpenes (79.05%) and sesquiterpenes (10.33%) were dominant in the EO, with camphor, (+/-)-lavandulol and eucalyptol being the major constituents, representing 55.06% of the total EO. The EO possessed potent phytotoxicity against Poa annua and Medicago sativa starting from 0.5 mg/mL, and when the concentration rose to 5 mg/mL, seed germination of both tested species was 100% suppressed. Ajania tibetica EO displayed significant pesticidal activity against Aphis gossypii with an LC50 value of 17.41 μg/mL; meanwhile, the EO also showed antimicrobial activity against Escherichia coli, Bacillus subtilis, Verticillium dahlia and Aspergillus niger using broth microdilution and disc diffusion methods. For the tested bacterial and fungal strains, the EO exhibited a repressing effect, with minimum inhibitory concentrations (MICs) ranging from 0.3125 to 1.25 mg/mL for bacteria and from 1.25 to 2.5 mg/mL for fungi, whereas the minimum microbicidal concentrations (MMCs) were 5 mg/mL for bacteria and 2.5 mg/mL for fungi. Our study is the first report on the chemical profile as well as the phytotoxicity, insecticidal and antimicrobic activity of A. tibetica EO, indicating its potential value as an alternative synthetic pesticide.

Allelopathic potential and allelochemical composition in different soil layers of Rhododendron delavayi forest, southwest China

Forests habituated by Rhododendron delavayi often lack understory vegetation, which could possibly be a consequence of allelopathy. It is a phenomenon by virtue of which certain plant species produce allelochemicals that affect the growth and behavior of surrounding plants. To elucidate the allelopathic potential and allelochemicals present in the different layers of a R. delavayi forest, extracts obtained from three layers of the forest were used for seed germination bioassays and gas chromatography-mass spectrometry (GC–MS) analysis. Aqueous extracts of the litter and humus layers significantly inhibited the seed germination of R. delavayi, Festuca arundinacea, and Lolium perenne, with the litter layer causing the strongest inhibitory effect. A total of 26 allelochemicals were identified in the litter, humus, and soil layers by GC–MS analysis. The primary allelochemicals in the soil and humus layer were organic acids, while the main allelochemicals in the litter layer were phenolic acids. The redundancy analysis revealed the significance of total nitrogen (TN) and relative water content (RWC) in explaining the distribution of the allelochemicals. The results indicated that the litter layer exerted the maximum allelopathic effect due to presence of maximum amount of allelochemical especially the phenolic acids.

Efficacy of Sterculia diversifolia Leaf Extracts: Volatile Compounds, Antioxidant and Anti-Inflammatory Activity, and Green Synthesis of Potential Antibacterial Silver Nanoparticles

Sterculia diversifolia, widely distributed in Jordan as an ornamental plant, is a synonoum for Brachychiton populneus. Phytochemical studies examining the volatile chemicals in Sterculia diversifolia leaves are limited, despite the rising demand for their numerous applications. Furthermore, it was only recently that a report described the friendly synthesis of silver nanoparticles (AgNPs) using aqueous extract derived from Brachychiton populneus leaves. Therefore, AgNPs were produced using either aqueous plant extracts (AgWPE) or ethanolic plant extracts (AgEPE), and Shimadzu GC-MS equipment was used to detect volatile compounds in the ethanolic leaf extracts. GC-MS profile of leaf ethanolic extracts of the Jordanian chemotypes of S. diversifolia revealed the existence of major components: (3β)-Lup-20(29)-en-3-ol acetate (30.97%) and 1-octadecyne (24.88). Other compounds are squalene (7.19%), germanicol (6.23), dl-α-tocopherol (5.24), heptacosane (4.41), phytol (3.54) and pentacosane (2.89). According to published studies, these reported chemicals have numerous uses, including as animal feed, vitamin precursors, possible eco-friendly herbicides, antioxidants, and anti-inflammatory agents. Aqueous extracts of S. diversifolia leaves had total phenolic of 5.33 mg GAE/g extract and flavonoid contents of 64.88 mg QE/g extract, respectively. The results indicated the contribution of phenolic and flavonoids to this plant’s anti-inflammatory and antioxidant properties. The reduction in AgNO₃ to AgNPs using S. diversifolia leaf extracts was confirmed by the change in solution color from colorless to dark black. Further characterization was attempted by X-ray diffraction, Malvern zeta-sizer and scanning electron microscope. The efficacy of synthesized Ag nanoparticles using aqueous or ethanolic plant extract of S. diversifolia against the Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus showed appreciable activity at 25 µg/mL concentration compared to the source plant extracts.