Enhancement of N-Methyl Amino Acid Incorporation into Proteins and Peptides Using Modified Bacterial Ribosomes and Elongation Factor P.

N-Methylated amino acids are constituents of natural bioactive peptides and proteins. Nα-methylated amino acids appear abundantly in natural cyclic peptides, likely due to their constraint of peptide conformation and contribution to peptide stability. Peptides containing Nα-methylated amino acids have long been prepared by chemical synthesis. While such natural peptides are not produced ribosomally, recent ribosomal strategies have afforded Nα-methylated peptides. Presently, we define new strategies for the ribosomal incorporation of Nα-methylated amino acids into peptides and proteins. First, we identify modified ribosomes capable of facilitating the incorporation of six N-methylated amino acids into antibacterial scorpion peptide IsCT. Also synthesized analogously was a protein domain (RRM1) from hnRNP LL; improved yields were observed for nearly all tested N-methylated amino acids. Computational modeling of the ribosomal assembly illustrated how the distortion imposed by N-methylation could be compensated by altering the nucleotides in key 23S rRNA positions. Finally, it is known that incorporation of multiple prolines (an N-alkylated amino acid) ribosomally can be facilitated by bacterial elongation factor P. We report that supplementing endogenous EF-P during IsCT peptide and RRM1 protein synthesis gave improved yields for most of the N-methylated amino acids studied.

Gibberellic acid promotes single-celled fiber elongation through the activation of two signaling cascades in cotton.

The agricultural green revolution spectacularly enhanced crop yield through modification of gibberellin (GA) signaling. However, in cotton, the GA signaling cascades remain elusive, limiting our potential to cultivate new cotton varieties and improve yield and quality. Here, we identified that GA prominently stimulated fiber elongation through the degradation of DELLA protein GhSLR1, thereby disabling GhSLR1's physical interaction with two transcription factors, GhZFP8 and GhBLH1. Subsequently, the resultant free GhBLH1 binds to GhKCS12 promoter and activates its expression to enhance VLCFAs biosynthesis. With a similar mechanism, the free GhZFP8 binds to GhSDCP1 promoter and activates its expression. As a result, GhSDCP1 upregulates the expression of GhPIF3 gene associated with plant cell elongation. Ultimately, the two parallel signaling cascades synergistically promote cotton fiber elongation. Our findings outline the mechanistic framework that translates the GA signal into fiber cell elongation, thereby offering a roadmap to improve cotton fiber quality and yield.

Selective Separation of U(VI) from Pu(IV) by 2,9-Diamide-1,10-phenanthroline Ligands at High Acidity: Extraction and Coordination Chemistry.

During the PUREX process, the separation between U(VI) and Pu(IV) is achieved by reducing Pu(IV) to Pu(III), which is complicated and energy-consuming. To address this issue, we report here the first case of separation of U(VI) from Pu(IV) by o-phenanthroline diamide ligands under high acidity. Two new o-phenanthroline diamide ligands (1,10-phenanthroline-2,9-diyl)bis(indolin-1-ylmethanone) (L1) and (1,10-phenanthroline-2,9-diyl)bis((2-methylindolin-1-yl)methanone) (L2) were synthesized, which can effectively separate U(VI) from Pu(IV) even at 4 mol/L HNO3. The highest separation factor of U(VI) and Pu(IV) can reach over 1000, setting a new record for the separation of U(VI) from Pu(IV) under high acidity. Furthermore, extracted U(VI) can be easily recovered with water or dilute nitric acid, and the extraction performance remains stable even after 150 kGy gamma irradiation, which provides solid experimental support for potential engineering applications. The results of UV-vis titration and single-crystal X-ray diffraction measurements show that the 1:1 complex formed by L1 with U(VI) is more stable than all of the previously reported phenanthroline ligands, which reasonably reveals that the ligand L1 designed in this work has excellent affinity for U(VI). The findings of this work promise to contribute to the facilitation of the PUREX process by avoiding the use of reducing agents. It also provides new clues for designing ligands to achieve efficient separation between U(VI) and Pu(IV) at high acidity.

Mesoporous polyacrylic acid/calcium phosphate coated persistent luminescence nanoparticles for improved afterglow bioimaging and chemotherapy of bacterial infection.

Coating mesoporous drug carriers on the surface of persistent luminescence nanoparticles (PLNPs) not only allows continuous luminous imaging without spontaneous fluorescence interference, but also provides drug release guidance. However, in most cases, the encapsulation of the drug-loaded shells significantly reduces the luminescence of PLNPs, which is unfavorable for bioimaging. In addition, conventional drug-loaded shells alone, such as silica shells, have difficulty in achieving responsive fast drug release. Herein, we report the fabrication of mesoporous polyacrylic acid (PAA)/calcium phosphate (CaP) shell-coated PLNPs (PLNPs@PAA/CaP) for improved afterglow bioimaging and drug delivery. The encapsulation of the PAA/CaP shell effectively prolonged the decay time and enhanced the sustained luminescence of PLNPs by about three times due to the passivation of the surface defects of PLNPs by the shell, and the energy transfer between the shell and PLNPs. Meanwhile, the mesoporous structure and negative charge of the PAA/CaP shells enabled the prepared PLNPs@PAA/CaP to carry the positively charged drug doxycycline hydrochloride efficiently. Under the acidic conditions of bacterial infection, the degradation of PAA/CaP shells and the ionization of PAA enabled fast drug release for effective killing of bacteria at the infection site. The excellent persistent luminescence properties, outstanding biocompatibility, and rapid responsive release feature make the prepared PLNPs@PAA/CaP a promising nanoplatform for diagnostic and therapeutic applications.

Activation of d-Asparagine and d-Glutamine Derivatives Using the Mitsunobu Reaction.

Seven d-amino acid derivatives having reactive side chains have been activated to afford their respective 3,5-dinitrobenzyl esters using the Mitsunobu reaction. This esterification was found to be difficult using traditional methods involving 3,5-dinitrobenzyl chloride under alkaline conditions. The conversion of a tRNA to the respective d-glutaminyl-tRNA using d-glutamine 3,5-dinitrobenzyl ester was catalyzed by a flexizyme, followed by purification to remove all the unacylated tRNAs and other byproducts. Both d- and l-glutamine were incorporated from their aminoacyl-tRNAs into a model peptide structurally related to IFN-ß.

A Retrospective, Nested Case-Control Study to Develop a Biomarker-Based Model for ARDS Diagnostics.

BACKGROUND: Several biomarkers could be intercalated with traditional measures to improve ARDS diagnostics. METHODS: There were 211 ICU patients enrolled in this retrospective, nested case-control study. Participants were divided into an ARDS (n = 79) and non-ARDS (n = 132) groups, according to the Berlin criteria. Patient characteristics, vital signs, and laboratory tests were collected within three hours of admission. CC16, Ang-2, sRAGE, HMGB1, and SPD were measured within three hours and again at 24 hours, after admission to ICU. Receiver Operating Characteristic curves and multivariate logistic regression analyses were applied for predictive purposes. RESULTS: C-reactive protein (CRP), NT-proBNP, and pH values were intercalated with five established ARDS indicators, and the PaO2/FiO2 ratio. Only four potential indicators were analyzed, with CRP having high diagnostic value. Areas under curve (AUC) were as follows: CC16 (AUC: 0.752; 95% CI 0.680 - 0.824), Ang-2 (AUC: 0.695; 95% CI 0.620 - 0.770), HMGB1 (AUC: 0.668; 95% CI 0.592 - 0.744), sRAGE (AUC: 0.665; 95% CI 0.588 - 0.743), CRP (AUC: 0.701; 95% CI 0.627 - 0.776). No single indicator improved upon the PaO2/FiO2 ratio which had an AUC: 0.844 (95% CI 0.789 - 0.898). However, when the binary logistic model was transformed and the model was constructed, the AUC increased from 0.647 (95% CI 0.568 - 0.726) to 0.911 (95% CI 0.864 - 0.946). Among the combinations tested, PaO2/FiO2 + CRP + Ang-2 + CC16 + HMGB1 resulted in the highest AUC of 0.910 (95% CI 0.863 - 0.945), although there are other factors which must be considered. CONCLUSIONS: A combination of biomarkers could enhance ARDS diagnostics, which has obvious ramifications for patient care and prognosis. It may be possible to develop a predictive ARDS nomogram; however, of the combinations tested here, we tentatively recommend PaO2/FiO2 + CRP + Ang-2 + CC16 + HMGB1. This is because of the cost implications in contrast with benefit involved in utilizing the more elaborate model. Further health economics research is required to consider the opportunity cost for emergency care policy.

Novel phenylalanine-modified magnetic ferroferric oxide nanoparticles for ciprofloxacin removal from aqueous solution.

The pollution of natural water bodies by pharmaceutical compounds has led to serious concerns regarding ecological and public health safety. In this study, novel recyclable phenylalanine (Phe)-modified magnetic ferroferric oxide nanoparticles (Fe3O4@Phe NPs) were successfully synthesized for the first time using a simple one-pot method to remove ciprofloxacin (CIP) from aqueous solutions. Fe3O4 and Fe3O4@Phe NPs were characterized using different techniques, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Turbiscan analysis and vibrating-sample magnetometry (VSM). The results show that Fe3O4 NPs are fully encapsulated by Phe, exhibiting an average diameter of 200 nm, a high specific surface area (35.79 m2 g-1), good dispersion and superparamagnetic properties. The effects of Phe content, initial pH and ionic strength on CIP adsorption onto Fe3O4 and Fe3O4@Phe NPs are investigated. The maximal adsorption capacity of CIP onto Fe3O4@Phe NPs is determined to be 49.27 mg g-1. The adsorption kinetics and isotherms show that the adsorption process follows the pseudo-second-order-kinetic and Langmuir isotherm models, respectively. This indicates that the adsorption involves a rate-controlled monolayer chemisorption process. The regeneration experiments show that Fe3O4 and Fe3O4@Phe NPs exhibit good reusability for CIP adsorption. Adsorption mechanisms include electrostatic interactions, hydrogen bonding, hydrophobicity and π-π interactions. This study presents a promising strategy for the design and preparation of multifunctional nanoparticles to remove contaminants from the environment.

The role of the probiotic Akkermansia muciniphila in brain functions: insights underpinning therapeutic potential.

The role of Akkermansia muciniphila, one of the most abundant microorganisms of the intestinal microbiota, has been studied extensively in metabolic diseases, such as obesity and diabetes. It is considered a next-generation probiotic microorganism. Although its mechanism of action has not been fully elucidated, accumulating evidence indicates the important role of A. muciniphila in brain functions via the gut-brain axis and its potential as a therapeutic target in various neuropsychiatric disorders. However, only a limited number of studies, particularly clinical studies, have directly assessed the therapeutic effects of A. muciniphila interventions in these disorders. This is the first review to discuss the comprehensive mechanism of A. muciniphila in the gut-brain axis via the protection of the intestinal mucosal barrier and modulation of the immune system and metabolites, such as short-chain fatty acids, amino acids, and amino acid derivatives. Additionally, the role of A. muciniphila and its therapeutic potential in various neuropsychiatric disorders, including Alzheimer's disease and cognitive deficit, amyotrophic lateral sclerosis, Parkinson's disease, and multiple sclerosis, have been discussed. The review suggests the potential role of A. muciniphila in healthy brain functions.

Benzoic Acid Metabolism and Lipopolysaccharide Synthesis of Intestinal Microbiome Affects the Health of Ruminants under Free-Range and Captive Mode.

It is urgent to explore new ways to protect endangered wild animals and develop sustainable animal husbandry on the Qinghai-Tibet Plateau due to its fragile ecological environment. Ruminants, raised in captivity and free-range, have important niches in the Plateau and are the best models to analyze the effects of different feeding modes on their health. In this study, two ruminants, yaks and goats in free-range and captive modes, respectively, were selected to study the relationship between gut microbes and ruminant health. The results showed that the gut microbial diversity of free-range ruminants was higher than those of captive ruminants. Principal co-ordinates analysis (PCoA) showed that there were significant differences in the gut microbial communities in different breeding modes. Both the captive ruminants enriched the Succinivibrionaceae family, which had a strong potential to synthesize lipopolysaccharide, and the low exercise amount of the captive animals was significantly related to this function. Meanwhile, free-range ruminants enriched Oscillospiraceae, which had the potential to degrade benzoic acid, and this potential had a significant positive correlation with resistance to parasitic infections. We offer other possibilities, such as adding benzoic acid to feed or increasing the exercise time of captive ruminants to make them healthier.

Speckle-tracking echocardiography for detecting myocardial dysfunction in sepsis and septic shock patients: A single emergency department study.

BACKGROUND: Septic cardiomyopathy (SCM) occurs in the early stage of sepsis and septic shock, which has implications for treatment strategies and prognosis. Additionally, myocardial involvement in the early stages of sepsis is difficult to identify. Here, we assess subclinical myocardial function using laboratory tests and speckle-tracking echocardiography (STE). METHODS: Emergency department patients diagnosed with sepsis or septic shock were included for analysis. Those with other causes of acute or pre-existing cardiac dysfunction were excluded. Transthoracic echocardiography (TTE), including conventional echocardiography and STE, were performed for all patients three hours after initial resuscitation. Samples for laboratory tests were taken around the time of TTE. RESULTS: Left ventricular functions of 60 patients were analyzed, including 21 septic shock patients and 39 sepsis patients. There was no significant difference in global longitudinal strain (GLS), global circumferential strain (GCS), or global radical strain (GRS) between patients with sepsis and septic shock (all with P>0.05). However, GLS and GCS were significantly less negative in patients with abnormal troponin levels or in patients with abnormal left ventricular ejection fraction (LVEF) values (all with P<0.05). There were also moderate correlations between GLS and levels of cTnI (r=0.40, P=0.002) or N-terminal pro-B-type natriuretic peptide (NT-proBNP) (r=0.44, P=0.001) in sepsis and septic shock patients. CONCLUSION: Myocardial dysfunction, e.g., lower LVEF or less negative GLS in patients with sepsis or septic shock, is more affected by myocardial injury. GLS could be incorporated into mainstream clinical practice as a supplementary LVEF parameter, especially for those with elevated troponin levels.

Preparation of eugenol nanoemulsions for antibacterial activities.

Eugenol is a versatile plant essential oil, but its high volatility and low water solubility greatly limit its application. Accordingly, this study prepared eugenol nanoemulsions by a high-speed shearing technique. Through visual inspection and a series of characterizations, including dynamic light scattering, and confocal laser scanning microscopy, the optimized formula was determined to be 5% (w/w) oil phase (eugenol) and 8% (w/w) surfactant (Tween-80), and the optimized shearing time was 5 min. The optimized nanoemulsion had good stability, small droplets (85 nm), and uniform distribution. At a concentration of 0.02 mg µL-1, the nanoemulsion showed strong inhibition against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Scanning electron microscopy (SEM) images showed severe deformation and membrane rupture of both bacteria treated by the nanoemulsion. This result was further confirmed by the leakage of proteins in both bacteria after treatment. The results of reactive oxygen species (ROS) and malondialdehyde (MDA) measurements indicated that the increased levels of ROS in both bacteria treated by the nanoemulsion triggered lipid peroxidation, thus increasing the MDA levels, ultimately causing changes in cell membrane permeability and disruption of the membrane structure. In addition, the nanoemulsion had a small effect on the proliferation and apoptosis of hepatocytes (L02) and lung cells (BEAS-2B), indicating its good biocompatibility. In this study, we developed a novel eugenol nanoemulsion with high stability and good biological activity, which may provide a promising and effective method for wound treatment in the healthcare area.

Value of the triglyceride glucose index combined with body mass index in identifying non-alcoholic fatty liver disease in patients with type 2 diabetes.

BACKGROUND: The triglyceride glucose index combined with body mass index is a new index that reflects the degree of insulin resistance. In this cross-sectional study, we aimed to explore the predictive value of the triglyceride glucose-body mass index (TyG-BMI) in relation to the occurrence of non-alcoholic fatty liver disease (NAFLD) in the Chinese population with type 2 diabetes (T2D). METHODS: We selected 826 patients with T2D who were hospitalized at the Department of Endocrinology and Metabolism of Karamay People's Hospital from September 2016 to October 2018 for this research. The height, weight, fasting blood glucose, serum insulin, and lipid profiles of the subjects were collected. The liver ultrasound showed any degree of echogenic enhancement of liver tissue and the liver appeared brighter than the renal cortex on ultrasound were considered to be NAFLD. The logistic regression analysis was performed to estimate associations between the triglyceride glucose index (TyG), TyG-BMI index, insulin resistance index (HOMA-IR) and the ratio of the triglycerides to high-density lipoprotein-cholesterol with a diagnosis of NAFLD. The receiver operating characteristic curve method was used to analyze its predictive value for NAFLD. RESULTS: Results of the logistic regression analysis showed that the odds ratios of NAFLD were 6.535 (3.70-11.53) and 4.868 (2.576-9.200) for the TyG-BMI before and after correction,respectively(P < 0.001). The area under the curve (AUC) for TyG-BMI was 0.727 (0.691-0.764), which was the highest among all the other parameters studied. CONCLUSION: Compared with the TyG index, the TG/HDL-C and HOMA-IR, the TyG-BMI was a more effective predictor of NAFLD in T2D.

Linkage-Specific Synthesis of Di-ubiquitin Probes Enabled by the Incorporation of Unnatural Amino Acid ThzK.

Di-ubiquitin (diUB) conjugates of defined linkages are useful tools for probing the functions of UB ligases, UB-binding proteins and deubiquitinating enzymes (DUBs) in coding, decoding and editing the signals carried by the UB chains. Here we developed an efficient method for linkage-specific synthesis of diUB probes based on the incorporation of the unnatural amino acid (UAA) Nϵ -L-thiaprolyl-L-Lys (L-ThzK) into UB for ligation with another UB at a defined Lys position. The diUB formed by the UAA-mediated ligation reaction has a G76C mutation on the side of donor UB for conjugation with E2 and E3 enzymes or undergoing dethiolation to generate a covalent trap for DUBs. The development of UAA mutagenesis for diUB synthesis provides an easy route for preparing linkage-specific UB-based probes to decipher the biological signals mediated by protein ubiquitination.

Synthesis, antibacterial evaluation, and safety assessment of CuS NPs against Pectobacterium carotovorum subsp. carotovorum.

BACKGROUND: Copper agents have been widely used in crop protection because of their unique mechanism against resistant pathogenic bacteria; however, their application brings environmental pollution and biosafety problems. Therefore, environmentally friendly copper agents have attracted attention. In this study, copper sulfide nanoparticles (CuS NPs) were prepared, characterized, analyzed for antibacterial activity and safety. RESULTS: Characterization results showed that the prepared pure CuS NPs have flake nanostructures, hexagonal crystal system, and size range from 40 to 60 nm. These CuS NPs exerted excellent antibacterial effects [median effective concentration (EC50 ) = 17 mg L-1 ] against Pectobacterium carotovorum subsp. carotovorum (Pcc) in vitro and can effectively delay and reduce bacterial infection in vivo. Antibacterial mechanism analysis revealed that CuS NPs can increase the levels of reactive oxygen species (ROS) and lipid peroxidation and destroy the structure of bacterial cells as observed through scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy. These NPs can also inhibit the motility of Pcc. At 7 and 14 days, the 50% lethal concentrations (LC50 ) of CuS NPs against earthworms were 1136 and 783 mg kg-1 , respectively, indicating their low acute toxicity to earthworms and environmental friendliness. Furthermore, the cells (L02) treated by CuS NPs showed relatively high cell viability (> 96%) and low apoptosis rate (only 5.2%), proving that CuS NPs had low cytotoxicity. CONCLUSION: Compared with commercial dicopper chloride trihydroxide (Cu2 (OH)3 Cl), CuS NPs could be used as a highly effective, lowly toxic, and environmentally friendly antibacterial agent. © 2021 Society of Chemical Industry.

Identification of key genes involved in recovery from spinal cord injury in adult zebrafish.

Zebrafish are an effective vertebrate model to study the mechanisms underlying recovery after spinal cord injury. The subacute phase after spinal cord injury is critical to the recovery of neurological function, which involves tissue bridging and axon regeneration. In this study, we found that zebrafish spontaneously recovered 44% of their swimming ability within the subacute phase (2 weeks) after spinal cord injury. During this period, we identified 7762 differentially expressed genes in spinal cord tissue: 2950 were up-regulated and 4812 were down-regulated. These differentially expressed genes were primarily concentrated in the biological processes of the respiratory chain, axon regeneration, and cell-component morphogenesis. The genes were also mostly involved in the regulation of metabolic pathways, the cell cycle, and gene-regulation pathways. We verified the gene expression of two differentially expressed genes, clasp2 up-regulation and h1m down-regulation, in zebrafish spinal cord tissue in vitro. Pathway enrichment analysis revealed that up-regulated clasp2 functions similarly to microtubule-associated protein, which is responsible for axon extension regulated by microtubules. Down-regulated h1m controls endogenous stem cell differentiation after spinal cord injury. This study provides new candidate genes, clasp2 and h1m, as potential therapeutic intervention targets for spinal cord injury repair by neuroregeneration. All experimental procedures and protocols were approved by the Animal Ethics Committee of Tianjin Institute of Medical & Pharmaceutical Sciences (approval No. IMPS-EAEP-Q-2019-02) on September 24, 2019.

General Tolerance of Galactosyltransferases toward UDP-galactosamine Expands Their Synthetic Capability.

Accessing large numbers of structurally diverse glycans and derivatives is essential to functional glycomics. We showed a general tolerance of galactosyltransferases toward uridine-diphosphate-galactosamine (UDP-GalN), which is not a commonly used sugar nucleotide donor. The property was harnessed to develop a two-step chemoenzymatic strategy for facile synthesis of novel and divergent N-acetylgalactosamine (GalNAc)-glycosides and derivatives in preparative scales. The discovery and the application of the new property of existing glycosyltransferases expand their catalytic capabilities in generating novel carbohydrate linkages, thus prompting the synthesis of diverse glycans and glycoconjugates for biological studies.

The Microbiome-Gut-Brain Axis, a Potential Therapeutic Target for Substance-Related Disorders.

Substance addiction is a complex worldwide public health problem. It endangers both personal life and social stability, causing great loss on economy. Substance-related disorder is considered to be a complicated chronic brain disorder. It resulted from interactions among pharmacological properties of addictive substances, individual susceptibility, and social-environmental factors. Unfortunately, there is still no ideal treatment for this disorder. Recent lines of evidence suggest that gut microbiome may play an important role in the pathogenesis of neuropsychiatric disorders, including substance-related disorders. This review summarizes the research on the relationship between gut microbiome and substance-related disorders, including different types of substance, different individual susceptibility, and the occurrence and development of substance-induced mental disorders. We also discuss the potentiation of gut microbiome in the treatment of substance-related disorders, especially in the treatment of substance-induced mental disorders and manipulation on individuals' responsiveness to addictive substances.

Reduced expression of miR-30c-5p promotes hepatocellular carcinoma progression by targeting RAB32.

Hepatocellular carcinoma (HCC) remains among the most lethal of human cancers, despite recent advances in modern medicine. miR-30c-5p is frequently dysregulated in different diseases. However, the effects and the underlying mechanism of miR-30c-5p in HCC are still elusive. Here, we show that miR-30c-5p is downregulated in HCC and significantly associated with survival and tumor size in patients with HCC. We demonstrate that aberrant miR-30c-5p markedly affects HCC cell proliferation and migration. Further experiments show that RAB32 is an essential target of miR-30c-5p in HCC. These studies highlight an important role of miR-30c-5p in growth and invasion of HCC and indicate that the miR-30c-5p-RAB32 axis is an important underlying mechanism.

Preparation of peppermint oil nanoemulsions: Investigation of stability, antibacterial mechanism and apoptosis effects.

Peppermint oil (PO) is one of the most popular and widely used essential oils. However, due to volatile and poor water solubility of volatile oil, its application in the fields of medicine and food is limited. In order to solve this problem, the high speed shearing technology was used to prepare the nanoemulsion from PO. By using a series of characterization methods, such as turbiscan scanning spectrum, dynamic light scattering (DLS), confocal laser scanning microscope (CLSM), the best nanoemulsion formula was identified as PO 10 %, surfactant 8 % (Tween-60: EL-20 = 3:1) and deionized water 82 % (w/w). The inhibition strength of nanoemulsion on bacteria was evaluated by detecting the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) in Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) treated with peppermint oil nanoemulsion (PON) and observing the morphology of bacteria with biological scanning electron microscope (SEM). The results showed that PON had strong inhibitory effect on E. coli. At the concentration range of 0.02 µg/µL-0.2 µg/µL, the apoptosis rate of BEAS-2B cells was less than 10 % compared with control cells. All in all, the PON prepared under this formula is stable, which provides a reference for further exploration of essential oil as natural antibacterial materials in the future.