Applied Biological Chemistry最新文献

Fifty-four plant extracts from thirty-two medicinal plants collected in Nepal were evaluated for their inhibitory potential against the enzyme beta-secretase-1 (BACE1), to identify potential therapeutic agents for Alzheimer’s disease (AD). Of the studied extracts, rhizome extract of Rheum australe D. Don showed the highest inhibitory potential, with an IC₅₀ value of 0.872 ± 0.006 µg/mL. After BACE1 inhibitory activity check using 9 fractions collected from Prep-HPLC, further profiling of the metabolites of the best fraction 7 was performed using high-resolution mass spectrometry (HRMS). Results revealed the presence of diverse secondary metabolites, including aloe-emodin-8-O-β-D-glucoside, rhein-8-O-glucoside, piceatannol-3’-O-β-D-glucoside, emodin-8-glucoside, physcion 8-O-β-D-glucoside, desoxyrhaponticin, chrysophanol-8-O-glucoside, rhapontigenin, rhein, desoxyrhapontigenin, piceatannol, chrysophanol, physcion, and aloe-emodin. In-silico docking simulations were performed to identify potent compounds with high binding efficiencies to BACE1. Compound picetannol-3’-O-β-D-glucoside showed the best binding energy (-53.494 kcal/mol) and inhibitory potential with an IC₅₀ value of 1.270 ± 0.130 µM for BACE1. These results suggested that the R. australe D. Don extract is a promising agent for the treatment of AD.

Milk thistle (Silybum marianum) is a Mediterranean herb renowned for its liver-protective, antioxidant, anti-inflammatory, and detoxifying properties, primarily attributed to the bioactive compound silymarin. Recent studies have also highlighted its potential efficacy against COVID-19, contributing to the growing demand for milk thistle dietary supplements, particularly for liver health and immunity support. Milk thistle seeds, rich in silymarin and unsaturated fatty acids, hold significant industrial value as both medicinal and oilseed crops. To meet the growing demand, it is essential to develop standardized seeds, cultivation practices, and extraction methods aimed at maximizing yields of silymarin and other valuable metabolites. Recent advancements in genetic and genomic research, including the development of the first reference genome of S. marianum, have played a pivotal role in elucidating the biosynthesis pathways of silymarin and optimizing phytochemical production. This review highlights recent advancements in the genetics, genomics, and biochemistry of milk thistle, with particular emphasis on the importance of diverse genetic resources and AI-driven phenomics strategies, such as hyperspectral and RGB imaging, for high-yield and chemotype breeding. Further, feasibility of developing elite cultivars through molecular approaches, such as genome editing and metabolic engineering, is also discussed as the new traits obtained this way would be key to enhancing the commercial value of milk thistle in light of mass production of phytochemicals to meet rising market demands.

Thymic stromal lymphopoietin (TSLP) is a cytokine derived from epithelial cells and plays an essential role in the onset and activation of Th2-derived allergic inflammatory conditions, including atopic dermatitis. Despite their potential as drug targets, well-defined small molecules that effectively block TSLP expression are still lacking. A plant-derived secondary metabolite, aurone, was derivatized based on bioisosteric replacement to identify compounds that inhibit the promoter activity of TSLP. Thirteen (E)-2-benzylidene-1-indanones were designed and synthesized, and their structures were identified using NMR spectroscopy and mass spectrometry. Inhibition of the expression of TSLP triggered by interleukin-4 (IL-4) caused by (E)-2-benzylidene-1-indanones was measured using a TSLP gene promoter-reporter activity assay. Because compound 12, (E)-5-methoxy-2-(3-methoxybenzylidene)-2,3-dihydro-1H-inden-1-one, showed the best activity, further biological experiments, including RT-PCR analysis, quantitative real-time PCR, and inhibitory effects on IL-4-induced early growth response-1 (EGR-1) expression, EGR-1 DNA-binding activity, and IL-4-induced phosphorylation of the mitogen-activated protein kinase (MAPK) signaling cascade were performed. This study demonstrated that compound 12 acts on MAPK to block IL-4-triggered mRNA expression of TSLP via the MAPK-EGR-1 signaling pathway in HaCaT keratinocytes.

Aspergillus flavus is a pathogenic fungus with a broad host range, and its secondary metabolite, aflatoxin, recognized as the world’s first naturally occurring carcinogen. Nonetheless, the current control measures for A. flavus are inadequate, thus, it is imperative to seek alternative control methods for this species. In the present study, we identified an antimicrobial peptide AMP-17, which was found to effectively inhibit the conidial germination, growth, conidiation, and aflatoxin production of A. flavus. Additionally, our investigation revealed that the inhibition of A. flavus by AMP-17 is primarily attributed to increase cell membrane permeability, modify cell surface morphology, and compromise cellular integrity, as observed through flow cytometry and scanning electron microscopy. Transcriptome analysis indicated significant transcriptional changes in several genes associated with cell wall, cell membrane, cell cycle, detoxification, and aflatoxin biosynthesis in response to AMP-17 treatment, suggesting disruption of these cellular processes and pathways in A. flavus. Furthermore, AMP-17 exhibited a broad-spectrum antifungal activity against Aspergillus spp. These findings provide a strong theoretical basis for the potential use of AMP-17 as an effective antifungal agent against A. flavus.

The study examined the optimal production conditions and application rates of biochar derived from greenhouse crop by-products to enhance soil improvement and increase crop yield, thereby promoting sustainable agriculture in South Korea. The expansion of greenhouse cultivation has resulted in significant waste management challenges, and biochar production has emerged as a promising recycling solution for these by-products. Biochar was produced from red pepper stalks through pyrolysis at 200 to 600 °C, and its chemical properties, including pH, EC, T-C, and T-N, were analyzed. In this study, the chemical properties of biochar showed a significant increase in pH (from 5.8 to 10.3), EC (from 46.0 to 119.5 dS m⁻¹), and T-C (from 47.7 to 63.1%) with rising pyrolysis temperatures, while T-N decreased due to nitrogen volatilization above 300 °C. In the lettuce cultivation experiment, biochar application significantly improved fresh weight yield, with the biochar-treated group achieving a maximum of 83.3 g pot^− 1 in the first cropping season, compared to 62.8 g pot^− 1 in the NPK-only treatment group. However, excessive biochar application rates (≥ 800 kg ha⁻¹) led to yield reductions in the second cropping season, likely due to increased soil pH and EC. These results suggest the potential of recycling greenhouse crop residues into biochar to enhance soil fertility and crop productivity while indicating the need to manage application rates to minimize negative impacts from excessive use.

Soil microbial communities are crucial to ecosystem functionality, influencing soil fertility and health. Microbial diversity in soil is impacted by various land-use practices and environmental conditions, but the effects on both prokaryotic and eukaryotic communities remain insufficiently understood. This study investigates the influence of different land-use types and soil chemical properties on the composition and diversity of prokaryotic and eukaryotic microbes using next-generation sequencing (NGS). Soil samples were collected from seven distinct locations in South Korea, representing various land uses, including paddy fields, upland fields, forest areas, hydrocarbon- and heavy-metal-contaminated sites, greenhouse soils, and reclaimed tidal soils. Alpha diversity, assessed using Chao1 and Shannon indices, and beta diversity, evaluated through Bray-Curtis dissimilarity and Principal Coordinates Analysis (PCoA), were used to characterize microbial diversity. Soil chemical properties were analyzed, and their relationships with microbial community structure were examined. Results revealed significant variations in both prokaryotic and eukaryotic diversities across different land uses. Soils under conventional agricultural management (paddy and upland fields) showed higher microbial diversity compared to soils with high salinity, contamination, or low suitability for agriculture. Prokaryotic communities were dominated by Proteobacteria, Chloroflexi, Acidobacteria, and Bacteroidetes, with variations in abundance linked to soil condition and quality. Eukaryotic communities predominantly consisted of Opisthokonta, SAR (Stramenopiles, Alveolates and Rhizaria), and Amoebozoa, with distinct abundance patterns across different soils. In conclusion, land-use practices and soil chemical properties significantly influence microbial diversity and community composition. Soils subjected to less stress, e.g., agricultural soils, exhibited higher microbial diversity, while stressed soils, e.g., contaminated and saline soils, showed reduced diversity. These findings emphasize the importance of understanding the interplay between land management and microbial ecology for optimizing soil fertility and health.

Plastic pollution is of critical environmental concern, thus biodegradable plastics (BPs) have emerged as a potential solution to limit plastic waste accumulation. However, the fate of BPs in the environment, particularly their degradation and the subsequent generation of biodegradable microplastic (BMP) particles, remains poorly understood. This review aims to provide comprehensive insights into the biodegradation process of BPs and their impacts on soil and freshwater environments. Microorganisms play a pivotal role in this process by dismantling polymer chains into smaller particles. Factors influencing biodegradation rates include polymer composition, environmental conditions (e.g., temperature, ultraviolet radiation (UV), and pH), and the presence of chemical additives. However, incomplete degradation can result in BMPs, potentially perpetuating their presence in the environment and posing risks to ecosystems and organisms. This review consolidates understanding the mechanisms governing biodegradation and BMP formation, which is imperative for evaluating their environmental consequences and devising effective strategies for managing plastic waste.

Recent anthropogenic activities have spurred unparalleled environmental changes, among which elevated salinity levels emerge as a substantial threat to plant growth and development. This threat is characterized by oxidative stress, marked by the excessive generation of reactive oxygen species (ROS), proline accumulation, and lipid peroxidation. This study investigated the response of four maize (Zea mays L.) genotypes - two tolerant (9120 and Super Gold) and two susceptible (Pacific 984 and PS999) - to salinity-induced oxidative stress. Seedlings aged seven days were exposed to 12 dSm^− 1 salinity stress for five days, with various parameters including relative water content (RWC), ROS accumulation, proline levels, lipid peroxidation, lipoxigenase (LOX) activity, enzymatic and non-enzymatic antioxidants, and glyoxalases evaluated in fully expanded leaves. Susceptible genotypes exhibited higher RWC loss compared to tolerant genotypes, while proline accumulation was elevated in the latter. Enhanced ROS production (hydrogen peroxide and superoxide), melondialdehyde (MDA) levels, and LOX activity were observed in susceptible genotypes under salinity stress, along with increased oxidation of glutathione (GSH) and ascorbate (ASA) compared to tolerant genotypes. Enzymatic antioxidants such as superoxide dismutase (SOD), peroxidase (POD), glutathione peroxidase (GPX), and monodehydroascorbate reductase (MDHAR) displayed higher activity in tolerant genotypes, while catalase (CAT) activity was significantly different between tolerant and susceptible genotypes under salinity stress in maize. Conversely, elevated activities of ascorbate peroxidase (APX), glutathione S-transferase (GST), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) were observed in both genotypes, indicating their crucial role in cellular protection against ROS and metabolites during salt stress. In short, plants have devised tactics to scavenge surplus Reactive Oxygen Species (ROS) and uphold cellular redox balance amidst oxidative stress. This study aims to offer basic knowledge regarding both enzymatic and nonenzymatic antioxidants, and the defense mechanisms they constitute against ROS detoxification upon salt stress conditions; furthermore, it also explores their interactions with cellular components.

The plant cell wall is composed of a primary and secondary cell wall. The secondary cell wall (SCW) plays a crucial role in the movement of nutrients and water and serves as a barrier against pathogens and environmental stresses. However, the biosynthesis of the SCW is complex, involving a network of genes regulated by environmental factors, including light. In this study, we investigated the nuclear localization of AtGATA5 to determine its potential role as a transcription factor and its involvement in SCW formation. To explore changes in leaf phenotypes in overexpression AtGATA5 and the thickening of interfascicular fiber cells, we conducted a transient activity assay using Arabidopsis protoplasts. The results demonstrated that AtGATA5 can up-regulate NAC-domain transcription factors, which are master regulators of the SCW biosynthesis pathway. Furthermore, gene expression analysis in plants confirmed that as AtGATA5 expression increased, the expression levels of NAC-domain transcription factors also increased. These findings suggest that AtGATA5 plays a functional role in SCW formation by up-regulating master regulators in the SCW biosynthesis pathway. Overall, AtGATA5 may act as a novel regulator of SCW biosynthesis, offering insights into potential application.