Applied Biological Chemistry最新文献

Maize is highly sensitive to waterlogging stress, and seeds fail to germinate under hypoxic conditions induced by submergence, leading to severe yield losses. We conducted a comparative transcriptome analysis during the initial stages of seed germination, exploring aerobic and hypoxic conditions in two inbred lines, B73 and Okcheon Chal-1. Notably, significant differences emerged between aerobic and hypoxic conditions on the first day of germination, particularly in genes associated with fermentation and phytohormone regulation. However, consistent transcriptomic changes were observed in primary metabolic pathways such as glycolysis, the TCA cycle, and the pentose phosphate pathway. These differences strongly correlate with each other, illustrating the efficacy of the hypoxic response for survival in water. Furthermore, this suggests that germinating seeds serve as a promising model for studying plant hypoxia responses with controlled environmental conditions. Insights from this study contribute to understanding the fundamental mechanisms of hypoxia response and hold promise for developing strategies to cultivate waterlogging-tolerant maize cultivars.

Tea (Camellia sinensis (L.) O. Kuntze) is a popular beverage consumed worldwide. To establish fundamental scientific data, we analyzed the amino acids and volatile compounds in seven tea cultivars grown in Korea investigated phenotype also. Phenotypically, the leaf area and greenness index of young shoots and leaf blades were particularly different among the four Korean cultivars. Nine amino acids were detected from each cultivar, with the total amino acid and theanine contents being 9.08–41.42 and 2.81–24.60 mg/g, respectively. Moreover, 107 volatile compounds were identified as common components among tea cultivars using headspace solid-phase microextraction / gas chromatography–mass spectrometry (HS-SPME/GC-MS), and 38 key compounds were identified using partial least squares-discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA). The (Z)-linalool oxide (furanoid) concentrations were significantly high in Korean tea plant cultivars, and linalool concentrations were also high or low, but had high relative contents. Linalool and its various oxides are the major compounds responsible for the tea aroma. In conclusion, Korean tea cultivars have distinct characteristics, and the results of this study will form the basis for identifying Korean tea plant cultivars that can produce high-value tea products.

Wild-simulated ginseng (WSG, Panax ginseng C.A. Meyer) is grown in mountainous forests, without the chemical treatment or installation of artificial facilities. This study aimed to investigate monthly changes in growth characteristics and ginsenoside contents in WSG to suggest the optimal harvest time. Four-year-old WSG were collected in the same area every month, and their growth characteristics and ginsenoside contents were measured. The growth characteristics of aerial and root parts were measured from May to July and from March to December, respectively. For the aerial part, most growth characteristics of WSG decreased over time, except for stem length. For the root part, rhizome length increased over time except for September, while the root diameter and weight of root part were mostly consistent. The root length increased by September, while the number of rootlets was the highest at May. At July, the total ginsenoside content of WSG was significantly the highest, while the total ginsenoside content at October was the lowest. This result was believed to be due to the F2, Rd, and Rg1 contents of the aerial part, rather than the root part. Also, based on these growths and the ginsenoside contents of WSG, the optimal harvest time for WSG is considered to be late spring–summer (May–July) when the aerial part can be identified.

The investigation presented a novel finding regarding mitigating stress induced by chlorpyrifos in Eisenia fetida by incorporating biochar derived from rice straw and fly ash as soil amendments. It was observed that phenolic compounds exhibit solubility in methanol, and the methanolic fraction exhibited notable inhibitory effects on lipid peroxidation and displayed antioxidant properties. The defence mechanism of E. fetida, comprising catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and various other enzymes, remained effective in neutralizing stressors without disruption when the earthworm was subjected to diverse chemical agents or stressful conditions. These enzymes served as indicative markers of toxicity induced by pesticide exposure, even at sublethal concentrations. The scavenging of free radicals by these enzymes ultimately safeguarded the organism. Fly ash and biochar emerged as two organic alternatives capable of alleviating stress by providing a protective mechanism. In this context, the study examined the impact of biochar and fly ash amendments on earthworm biomarkers. The mortality rate at the median lethal concentration of chlorpyrifos was reduced to less than 50% through 3% and 5% modifications. In contrast to the non-amendment group exposed to sublethal doses, the amendment group exhibited higher levels of oxidative stress and lower protein content. This observation indicated the presence of stress induced by the accumulation of free radicals, which increased in number with higher doses of chlorpyrifos. Moreover, the study highlighted the interconnected nature of total antioxidant capacity and total phenolic capacity values, with a decrease in these parameters signifying a shift in earthworm biomarkers.

Graphical abstract

Rhododendrons produce a variety of methoxyflavonoids, including rarely found 3-methoxyflavonoids and 5-methoxyflavonoids. It was thus suggested that they have a series of regiospecific flavonoid O-methyltransferases (FOMTs). The 18 Class II O-methyltransferase (OMT) genes were retrieved from the Rhododendron delavayi genome, designating them as RdOMTs. A comprehensive biochemical characterization of RdOMTs was performed to identify functional FOMTs. The FOMT activity of recombinant RdOMTs was assayed with flavonoid substrates of different subclasses. Among the examined RdOMTs, RdOMT3, RdOMT10, and RdOMT12 showed FOMT activity for diverse flavonoids. In particular, RdOMT3 consumed only flavonols as a substrate. Structural analyses of the methylated products demonstrated that RdOMT3, RdOMT10, and RdOMT12 catalyze regiospecific methylation of flavonoids at the 3'/5'-, 3-, and 4'-hydroxyl groups, respectively. Their broad substrate spectrum and different regiospecificity suggest that these RdOMTs contribute to the formation of complex methoxyflavonoids in R. delavayi. Bioconversion of flavonoids using E. coli harboring each RdOMT demonstrated that RdOMT3, RdOMT10, and RdOMT12 are useful tools for the biotechnological production of valuable methoxyflavonoids, including the rarely found 3-methoxyflavonoids.

Ten isatin-based hydrazone derivatives were synthesized using two subseries, IA (isatin + acetophenone) and IB (isatin + benzaldehyde), and evaluated for their monoamine oxidases (MAOs) inhibitory activity. All the compounds showed stronger MAO-A inhibition than MAO-B, and the IB series showed more effective MAO-A inhibitory activity than IA series. Compound IB4 most potently inhibited MAO-A (half maximal inhibitory concentration IC₅₀ = 0.015 µM), followed by IB3 (IC₅₀ = 0.019 µM). On the contrary, compound IB3 showed the highest MAO-B inhibition (IC₅₀ = 0.068 µM), followed by IB4 (IC₅₀ = 1.87 µM). Compound IB3 and IB4 had low selectivity indices of 3.68 and 8.50, respectively. Structurally, the methyl group of IA series decreased the inhibition of both MAO-A and MAO-B. Among them, IB3 and IB4 (4-Cl and 4-Br in B-ring, respectively) showed higher MAO-A and MAO-B inhibition than the other substitutions. Inhibition constant K_i values of IB3 and IB4 for MAO-A were 0.0088 and 0.0063 µM, respectively, and those for MAO-B were 0.048 and 0.060 µM, respectively. IB3 and IB4 were competitive, reversible inhibitors of MAO-A and MAO-B. Molecular docking analysis predicted that IB3 and IB4 formed stable hydrogen bonds between Asn181 and the NH atom of isatin in the ligand-protein complex. Dynamic analysis revealed that IB3 and IB4 are stable with both MAO isoforms. These observations suggest IB3 and IB4 are potent and reversible MAO-A and MAO-B inhibitors and both compounds can be used as therapeutic agents for neurological disorders.

Diabetes mellitus is a widespread endocrine disorder, which is categorized as the fourth leading cause of global mortality. Allopathic medicine has yet to provide a satisfactory cure for this condition. Consequently, there is an urgent demand for innovative antidiabetic treatment approaches with enhanced management and minimum side effects and costs. The study investigated the synergistic antidiabetic potential of combining selenium nanoparticles (Se NPs) and plasma-rich platelets (PRP) in diabetic mice. Antidiabetic activity of the proposed combination (Se NPs and PRP) was evaluated from histopathological and biochemical perspectives. The experiment involved alloxan monohydrate induced diabetic mouse model. In the in vivo study, several biochemical parameters for assessing the antidiabetic effect of the novel combination of (Se NPs and PRP) were performed such as blood glucose levels, body weight, lipid profiles, and liver damage markers (AST and ALT). Scavenging antioxidant activity was assessed by evaluation levels of hepatic and renal GSH, MDA, SOD, and CAT activities. Complete histopathological examinations of vital internal organs were carried out. Results revealed that combining Se NPs and PRP presents a novel approach for better diabetes management and reduced complications associated with the disease. These findings have therapeutic implications for managing diabetes mellitus.

Excessive clotting or abnormal platelet accumulation can lead to serious cardiovascular disorders such as atherosclerosis, stroke, and thrombosis. Therefore, it is imperative to identify compounds capable of controlling or impeding platelet aggregation to prevent the onset of cardiovascular diseases. Arteanoflavone, a compound extracted from Artemisia iwayomogi, has not garnered scientific recognition for its potential health benefits, recent studies have substantiated its anti-inflammatory, antioxidant, and anti-allergic properties. However, the precise mechanisms by which arteanoflavone influences platelet aggregation and blood clot formation have not been conclusively established. This research investigates arteanoflavone’s role in these processes, particularly in platelets induced by collagen. The study reveals a significant increase in the production of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) correlating with the administered dosage of arteanoflavone. Concurrently, a noticeable escalation is observed in substrates of cAMP-dependent kinase and cGMP-dependent kinase, specifically VASP and inositol 1,4,5-trisphosphate receptor (IP₃R).

Arteanoflavone demonstrates its ability to limit Ca²⁺ movement in the dense tubular system through IP₃R phosphorylation. Moreover, phosphorylated VASP inhibits the binding of fibrinogen to αIIb/β₃, thus suppressing platelet activity. Arteanoflavone also stimulates the phosphorylation of PI3K/Akt, a protein linked to platelet granule release, and MAPK (ERK, JNK, and p38) protein, associated with both platelet granule release and TXA₂ production.

Lastly, arteanoflavone impedes collagen-induced platelet aggregation and blood clot formation by inhibiting fibrin production in thrombin-induced platelets. Hence, it is suggested that arteanoflavone could be valuable as an agent that effectively deters platelet inhibition and blood clot formation through antiplatelet mechanisms.

Staphylococcus aureus remains a public health threat with the WHO classifying the pathogen as a high priority in the development of new antimicrobial agents. Whole genome sequencing has revealed a number of conserved genes that may be essential for cell viability and infection. Characterising the structure and function of these proteins will inevitably aid development of new antimicrobials. Therefore, this study elucidated the structure of hypothetical protein DUF3055 from S. aureus stain Mu50. The protein possesses an as yet undefined function and a unique fold. The size of DUF3055 made it an ideal candidate for NMR characterisation which in conjunction with circular dichroism revealed the protein to be folded. Crystallisation and structural solution found that the overall dimer fold has a negatively charged surface formed by a β-bulge and tightly crossed α-helices, with a complementary size to a DNA single turn. Our structural observations suggest that hypothetical protein DUF3055 from S. aureus has a role in DNA binding and gene regulation.

Morinda citrifolia L. (Noni) has been widely used in traditional medicine in tropical zones and has become increasingly popular globally owing to its health benefits. Most noni fruits are consumed as juice, which is traditionally produced by the natural fermentation of noni fruits. In this study, the metabolic profiles of noni fruit juice (NJ1) and fermented noni fruit juices (NJ2 and NJ3) was compared. A total of 74, 83, and 91 compounds including anthraquinones, coumarins, flavonoids, phenolic acids, phenolics, terpenoids, and miscellaneous (acids, carbohydrates, vitamins, fatty acids, etc.) were tentatively identified from NJ1, NJ2, and NJ3 in both positive and negative electrospray ionization modes. The phenolic compound composition differed significantly between noni juice and fermented noni juice. The results of the unsupervised principal component analysis and hierarchical clustering analysis showed that the non-fermented juice group clustered with the fermented juice groups. Asperulosidic acid, isoasperulosidic acid, and rutin levels were higher in the NJ1 group than those in the NJ2 group. Deacetylasperulosidic acid and monotropein contents in NJ2 were higher than those in NJ1. Similarly, NJ1 had higher asperulosidic acid and isoasperulosidic acid than those in NJ3. The findings from this study have the potential to enhance the quality of fermented noni juice.