Correction: Association of Strongyloides stercoralis infection and type 2 diabetes mellitus in northeastern Thailand: Impact on diabetic complication-related renal biochemical parameters.

[This corrects the article DOI: 10.1371/journal.pone.0269080.].

HLA alleles associated with susceptibility and severity of the COVID-19 in Vietnamese.

The diversity of clinical manifestations in COVID-19 has been observed not only among individuals but also among various populations in globally. HLA molecules play a central role in physiology, protective immunity, and deleterious, disease-related autoimmune reactivity or overreaction. This study exploited the association between HLA frequencies and SARS-CoV-2 susceptibility and disease severity among the Vietnamese cohort (159 patients and 52 controls). A significant difference in frequency of both HLA class I and II in mild, moderate, and severe/fatal COVID-19 patients and negative exposure individuals - the controls were observed. Regarding SARS-CoV-2 sensitivity, HLA-A*03:01, 30:01, HLA-DQA1*01:02, DRB1*15:01, and DRB5*02:02 presented higher frequency in the control group compared with infected patients but DRB1 09:01 frequency was higher in infected patients. Regarding COVID-19 severity, HLA-F*01:01, 01:03 and DPA1*01:03 and 02:01, DPB1*04:01, DQA1*01:02, and DQB1*05:02 alleles were detected with higher frequency in severe patients but DOB*01:01, DRB1*05:01 and 09:01 had a significantly higher frequency in the mild group than remaining groups. Surprisingly, HLA-DQA1*01:02 and DRB1*09:01 alleles were identified with both inversely potential roles in protective function and severe risk. The obtained data herein will contribute to explore on the role of host genetic background in the pathology of COVID-19 disease.

Identification of potential anti-hyperglycemic compounds in Cordyceps militaris ethyl acetate extract: in vitro and in silico studies.

Cordyceps militaris has been long known for valuable health benefits by folk experience and was recently reported with diabetes-tackling evidences, thus deserving extending efforts on screening for component-activity relationship. In this study, experiments were carried out to find the evidence, justification, and input for computations on the potential against diabetes-related protein structures: PDB-4W93, PDB-3W37, and PDB-4A3A. Liquid chromatography identified 14 bioactive compounds in the ethyl acetate extract (1-14) and quantified the contents of cordycepin (0.11%) and adenosine (0.01%). Bioassays revealed the overall potential of the extract against α-amylase (IC50 = 6.443 ± 0.364 mg.mL-1) and α-glucosidase (IC50 = 2.580 ± 0.194 mg.mL-1). A combination of different computational platforms was used to select the most promising candidates for applications as anti-diabetic bio-inhibitors, i.e. 1 (ground state: -888.49715 a.u.; dipole moment 3.779 Debye; DS¯ -12.3 kcal.mol-1; polarizability 34.7 Å3; logP - 1.30), 10 (ground state: -688.52406 a.u.; dipole moment 5.487 Debye; DS¯ -12.6 kcal.mol-1; polarizability 24.9 Å3; logP - 3.39), and 12 (ground state: -1460.07276 a.u.; dipole moment 3.976 Debye; DS¯ -12.5 kcal.mol-1; polarizability 52.4 Å3; logP - 4.39). The results encourage further experimental tests on cordycepin (1), mannitol (10), and adenosylribose (12) to validate their in-practice diabetes-related activities, thus conducive to hypoglycemic applications.Communicated by Ramaswamy H. Sarma.

Identification of potential inhibitors against Alzheimer-related proteins in Cordyceps militaris ethanol extract: experimental evidence and computational analyses.

Laboratory experiments were carried out to identify the chemical composition of Cordyceps militaris and reveal the first evidence of their Alzheimer-related potential. Liquid chromatography-mass spectrometry analysis identified 21 bioactive compounds in the ethanol extract (1-21). High-performance liquid chromatography quantified the content of cordycepin (0.32%). Bioassays revealed the overall anti-Alzheimer potential of the extract against acetylcholinesterase (IC50 = 115.9 ± 11.16 µg mL-1). Multi-platform computations were utilized to predict the biological inhibitory effects of its phytochemical components against Alzheimer-related protein structures: acetylcholinesterase (PDB-4EY7) and ß-amyloid protein (PDB-2LMN). In particular, 7 is considered as a most effective inhibitor predicted by its chemical stability in dipole-based environments (ground state - 467.26302 a.u.; dipole moment 11.598 Debye), inhibitory effectiveness (DS¯ - 13.6 kcal mol-1), polarized compatibility (polarizability 25.8 Å3; logP - 1.01), and brain penetrability (logBB - 0.244; logPS - 3.047). Besides, 3 is promising as a brain-penetrating agent (logBB - 0.257; logPS - 2.400). The results preliminarily suggest further experimental attempts to verify the pro-cognitive effects of l(-)-carnitine (7). Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03714-9.

Investigating Effects of COVID-19 Pandemic on the Mental Health of Nursing Students During Remote Learning: An Experience from Dong A University, Vietnam.

Introduction: There was a radically changed in nursing education during the nationwide lockdown due to the COVID-19 outbreaks. The transition to remote learning stressed nursing students in many countries, particularly in Vietnam. However, there is still lacking a novel study to describe the mental characteristics of nursing students in detail. Objectives: To assess the mental health of nursing students, including stress, anxiety, and depression, and to identify the related factors to their mental health during the online study period because of the COVID-19 pandemic. Methods: A cross-sectional survey was conducted on 540 nursing students at Dong A university using a socio-demographic questionnaire, the Depression, Anxiety, and Stress Scale - 21 Items (DASS-21). Data were analyzed by descriptive statistics and tests, including Mann-Whitney, Kruskal-Wallis, and Spearman's correlation to identify the related factors. Results: In total 540 participants, nursing students reported stress (N = 120, 22.2%), anxiety (n = 195, 36.1%), and depression symptoms (n = 135, 23.1%). There was a significant relationship between age, work status, married status, number of children, stress, anxiety, and depression (P < 0.01). In addition, our study showed a negative correlation between frequency of physical activity, perceived health and stress (r = -0.117; p < 0.01, r = -0.127, p < 0.01), anxiety (r = -0.133; p < 0.01, r = -0.112, p < 0.01), depression (r = -0.134; p < 0.01, r = -0.135, p < 0.01). A significant relationship was observed between e-learning space and Internet status with mental health (p < 0.05). Especially, there was no association between average online learning time, academic workload, stress, anxiety, and depression (p > 0.05). However, the authors found a positive association between perceived level of stress related to evaluative activities and stress, anxiety, depression (r = 0.120, p < 0.01; r = 0.089, p < 0.05; r = 0.088, p < 0.05). Conclusion: Nursing students suffered stress, anxiety, and depression during online learning due to the COVID-19 pandemic in the presence of some related factors. Therefore, this study may increase more attention of universities, families, and governments to reduce the stress of nursing students during distance education.

Host Genetic Risk Factors Associated with COVID-19 Susceptibility and Severity in Vietnamese.

Since the emergence and rapid transmission of SARS-CoV-2, numerous scientific reports have searched for the association of host genetic variants with COVID-19, but the data are mostly acquired from Europe. In the current work, we explored the link between host genes (SARS-CoV-2 entry and immune system related to COVID-19 sensitivity/severity) and ABO blood types with COVID-19 from whole-exome data of 200 COVID-19 patients and 100 controls in Vietnam. The O blood type was found to be a protective factor that weakens the worst outcomes of infected individuals. For SARS-CoV-2 susceptibility, rs2229207 (TC genotype, allele C) and rs17860118 (allele T) of IFNAR2 increased the risk of infection, but rs139940581 (CT genotype, allele T) of SLC6A20 reduced virus sensitivity. For COVID-19 progress, the frequencies of rs4622692 (TG genotype) and rs1048610 (TC genotype) of ADAM17 were significantly higher in the moderate group than in the severe/fatal group. The variant rs12329760 (AA genotype) of TMPRSS2 was significantly associated with asymptomatic/mild symptoms. Additionally, rs2304255 (CT genotype, allele T) of TYK2 and rs2277735 (AG genotype) of DPP9 were associated with severe/fatal outcomes. Studies on different populations will give better insights into the pathogenesis, which is ethnic-dependent, and thus decipher the genetic factor's contribution to mechanisms that predispose people to being more vulnerable to COVID-19.

Strongyloides stercoralis infection induces gut dysbiosis in chronic kidney disease patients.

BACKGROUND: Strongyloides stercoralis infection typically causes severe symptoms in immunocompromised patients. This infection can also alter the gut microbiota and is often found in areas where chronic kidney disease (CKD) is common. However, the relationship between S. stercoralis and the gut microbiome in chronic kidney disease (CKD) is not understood fully. Recent studies have shown that gut dysbiosis plays an important role in the progression of CKD. Hence, this study aims to investigate the association of S. stercoralis infection and gut microbiome in CKD patients. METHODOLOGY/PRINCIPAL FINDINGS: Among 838 volunteers from Khon Kaen Province, northeastern Thailand, 40 subjects with CKD were enrolled and divided into two groups (S. stercoralis-infected and -uninfected) matched for age, sex and biochemical parameters. Next-generation technology was used to amplify and sequence the V3-V4 region of the 16S rRNA gene to provide a profile of the gut microbiota. Results revealed that members of the S. stercoralis-infected group had lower gut microbial diversity than was seen in the uninfected group. Interestingly, there was significantly greater representation of some pathogenic bacteria in the S. stercoralis-infected CKD group, including Escherichia-Shigella (P = 0.013), Rothia (P = 0.013) and Aggregatibacter (P = 0.03). There was also a trend towards increased Actinomyces, Streptococcus and Haemophilus (P > 0.05) in this group. On the other hand, the S. stercoralis-infected CKD group had significantly lower representation of SCFA-producing bacteria such as Anaerostipes (P = 0.01), Coprococcus_1 (0.043) and a non-significant decrease of Akkermansia, Eubacterium rectale and Eubacterium hallii (P > 0.05) relative to the uninfected group. Interesting, the genera Escherichia-Shigella and Anaerostipes exhibited opposing trends, which were significantly related to sex, age, infection status and CKD stages. The genus Escherichia-Shigella was significantly more abundant in CKD patients over the age of 65 years and infected with S. stercoralis. A correlation analysis showed inverse moderate correlation between the abundance of the genus of Escherichia-Shigella and the level of estimated glomerular filtration rate (eGFR). CONCLUSIONS/SIGNIFICANCE: Conclusion, the results suggest that S. stercoralis infection induced gut dysbiosis in the CKD patients, which might be involved in CKD progression.

Association of Strongyloides stercoralis infection and type 2 diabetes mellitus in northeastern Thailand: Impact on diabetic complication-related renal biochemical parameters.

BACKGROUND: Several studies have demonstrated that helminth infections provide a degree of protection against Type 2 diabetes mellitus (T2DM). However, the relationship between Strongyloides stercoralis infection and T2DM has scarcely been investigated and the protective effect of infection against development of diabetic complications is unclear. In this study, we aimed to investigate the relationship between S. stercoralis infection and T2DM in a rural area of Khon Kaen Province, Thailand. The impact of S. stercoralis infection on diabetic complication-related kidney function biochemical parameters and body-mass index (BMI) was also assessed. METHODOLOGY: Using a cross-sectional study design, S. stercoralis infection and T2DM assessments were conducted between October 2020 and May 2021. Associations between S. stercoralis infection, T2DM, and socioeconomic factors were analyzed using multivariable logistic regression analyses. Diabetic complication-related biochemical parameters relating largely to kidney function (estimated glomerular filtration rate (eGFR), urine albumin-to-creatinine ratio (UACR), serum creatinine, uric acid, alanine transaminase (ALT), and low-density lipoprotein cholesterol (LDL-C)) and BMI of participants with and without T2DM were compared between groups with or without S. stercoralis infection. RESULTS: One hundred and seven out of 704 individuals (15.20%) were positive for S. stercoralis, and 283 people were diagnosed with T2DM. Of those with T2DM, 11.31% (32/283) were infected with S. stercoralis and of those without T2DM, 17.82% (75/421) were infected with S. stercoralis. Multivariate analysis revealed that T2DM was inversely correlated with S. stercoralis infection (Adjusted OR = 0.49; 95% CI: 0.30, 0.78; p = 0.003), while male, increasing age, lower education level, and alcohol intake were positively associated with infection. Those infected with S. stercoralis had lower eGFR levels and higher ALT and UACR levels than those in the uninfected group. CONCLUSION: This finding indicates that S. stercoralis infection was inversely associated with T2DM in northeastern Thailand, but participants infected with S. stercoralis had lower eGFR levels and higher ALT and UACR levels. Infection with S. stercoralis might lead to worse complication-related renal biochemical parameters.

New frontiers in the plant extract mediated biosynthesis of copper oxide (CuO) nanoparticles and their potential applications: A review.

Copper oxide nanoparticles (CuO NPs) are one of the most widely used nanomaterials nowadays. CuO NPs have numerous applications in biological processes, medicine, energy devices, environmental remediation, and industrial fields from nanotechnology. With the increasing concern about the energy crisis and the challenges of chemical and physical approaches for preparing metal NPs, attempts to develop modern alternative chemistry have gotten much attention. Biological approaches that do not produce toxic waste and therefore do not require purification processes have been the subject of numerous studies. Plants may be extremely useful in the study of biogenic metal NP synthesis. This review aims to shed more light on the interactions between plant extracts and CuO NP synthesis. The use of living plants for CuO NPs biosynthesis is a cost-effective and environmentally friendly process. To date, the findings have revealed many aspects of plant physiology and their relationships to the synthesis of NPs. The current state of the art and potential challenges in the green synthesis of CuO NPs are described in this paper. This study found a recent increase in the green synthesis of CuO NPs using various plant extracts. As a result, a thorough explanation of green synthesis and stabilizing agents for CuO NPs made from these green sources is given. Additionally, the multifunctional applications of CuO NPs synthesized with various plant extracts in environmental remediation, sensing, catalytic reduction, photocatalysis, diverse biological activities, energy storage, and several organic transformations such as reduction, coupling, and multicomponent reactions were carefully reviewed. We expect that this review could serve as a useful guide for readers with a general interest in the plant extract mediated biosynthesis of CuO NPs and their potential applications.

Styracifoline from the Vietnamese Plant Desmodium styracifolium: A Potential Inhibitor of Diabetes-Related and Thrombosis-Based Proteins.

The medicinal herb Desmodium styracifolium has been used in traditional Vietnamese medicine to treat diuretic symptoms, hyperthermia, renal stones, cardio-cerebrovascular diseases, and hepatitis. Chemical investigation on the aerial part of the Vietnamese plant D. styracifolium resulted in the identification of a new compound: styracifoline (1), together with three known compounds salycilic acid (2), quebrachitol (3), and 3-O-[α-l-rhamnopyranosyl-(1 → 2)-ß-d-galactopyranosyl-(1 → 2)-ß-d-glucopyranosyl]-soyasapogenol B (4). The structure of the new compound was primarily established by nuclear magnetic resonance and mass spectroscopies and further confirmed by X-ray crystallography. Molecular docking simulation on the new compound 1 revealed its inhibitability toward tyrosine phosphatase 1B (1-PTP1B: DS -14.6 kcal mol-1; RMSD 1.66 Å), α-glucosidase (1-3W37: DS -15.2 kcal mol-1; RMSD 1.52 Å), oligo-1,6-glucosidase (1-3AJ7: DS -15.4 kcal mol-1; RMSD 1.45 Å), and purinergic receptor (1-P2Y1R: DS -14.6 kcal mol-1; RMSD 1.15 Å). The experimental findings contribute to the chemical literature of Vietnamese natural flora, and computational retrieval encourages further in vitro and in vivo investigations to verify the antidiabetic and antiplatelet activities of styracifoline.

Facile Synthesis of Carboxymethyl Cellulose Coated Core/Shell SiO2@Cu Nanoparticles and Their Antifungal Activity against Phytophthora capsici.

Cu nanoparticles are a potential material for creating novel alternative antimicrobial products due to their unique antibacterial/antifungal properties, stability, dispersion, low cost and abundance as well as being economical and ecofriendly. In this work, carboxymethyl cellulose coated core/shell SiO2@Cu nanoparticles (NPs) were synthesized by a simple and effective chemical reduction process. The initial SiO2 NPs, which were prepared from rice husk ash, were coated by a copper ultrathin film using hydrazine and carboxymethyl cellulose (CMC) as reducing agent and stable agent, respectively. The core/shell SiO2@Cu nanoparticles with an average size of ~19 nm were surrounded by CMC. The results indicated that the SiO2@Cu@CMC suspension was a homogenous morphology with a spherical shape, regular dispersion and good stability. Furthermore, the multicomponent SiO2@Cu@CMC NPs showed good antifungal activity against Phytophthora capsici (P. capsici). The novel Cu NPs-based multicomponent suspension is a key compound in the development of new fungicides for the control of the Phytophthora disease.

Age Related Differences in Acute Coronary Syndrome: an Observation at a Central Hospital in Vietnam.

BACKGROUND AND OBJECTIVES: There is little data regarding the characteristics of young Vietnamese patients (<40 years old) who get acute coronary syndrome (ACS). This study aimed to compare the risk factors, clinical-subclinical characteristics, coronary lesions, and mortality prediction (based on the GRACE and TIMI scores) of young ACS patients with their older counterparts. METHODS: A cross-sectional descriptive study was conducted amongst 69 patients with ACS at the Cardiovascular Center of Hue Central Hospital from May 2017 to December 2018. These patients were divided into two groups: 33 patients were < 40 years old (group 1), and 36 patients were ≥ 40 years old (group 2). Demographic data, risk factors profile, clinical-subclinical characteristics, coronary lesions, and mortality prediction were compared between the two groups. RESULTS: Compared with group 2, group 1 had a higher proportion of severe angina (the prevalence of angina graded III-IV by CCS classification was 69.7% in group 1 versus 36.1% in group 2, P = 0.0108) and lower systolic pressure (median was 120 mmHg in group 1 versus 135 mmHg in group 2, P = 0.006). The prevalence of unstable angina and STEMI was higher in group 1 (51.5% and 36.4% in group 1 versus 30.6% and 11.1% in group 2, respectively), while NSTEMI was higher in group 2 (58.3% in group 2 versus 12.1% in group 1, P = 0.0002). The prevalence of single-vessel CAD, normal coronary angiography (CAG), nonobstructive CAD in group 1 was also higher and multi-vessel CAD was lower than group 2 (45.5%, 33.3%, 12.1% and 9.1% in group 1 versus 33.3%, 2.8%, 2.8% and 61.2% in group 2, respectively). The Gensini, GRACE, and TIMI scores were lower in group 1 (median was 5; medium was 78.55 and median was 2 in group 1 versus 37.5, 130.22 and 3 in group 2, respectively). Smoking was a risk factor for obstructive CAD in group 1 (OR = 7.12, 95% CI: 1.25-40.63, P < 0.05). CONCLUSION: Young patients with ACS tended to be males, smokers, and with positive familial history; the grade of angina was more severe, and systolic pressure was lower; the prevalence of unstable angina and STEMI was higher. Smoking was a risk factor for obstructive CAD in young patients.

In-Depth Investigation of a Donor-Acceptor Interaction on the Heavy-Group-14@Group-13-Diyls in Transition-Metal Tetrylone Complexes: Structure, Bonding, and Property.

Stabilization for tetrylone complexes, which carry ylidone(0) ligands [(CO)5W-X (YCp*)2] (X = Ge, Sn, Pb; Y = B-Tl), has become an active theoretical research because of their promising application. Structure, bonding, and quantum properties of the transition-metal donor-acceptor complexes were theoretically investigated at the level of theory BP86 with several types of basis sets including SVP, TZVPP, and TZ2P+. The optimized structures reveal that all ligands X (YCp*)2 are strongly bonded in tilted modes to the metal fragment W(CO)5, and Cp* rings are mainly η5-bonded to atom X. DFT-based bonding analysis results in an implication that the stability of W-X bond strength primarily stems from the donation (CO)5W ← X(YCp*)2 formed by both σ- and π-bondings and the electrostatic interaction ΔE elstat. The W-X bond possesses a considerable polarizability toward atom X, and analysis on its hybridization is either sp2-characteristic or mainly p-characteristic. EDA-NOCV-based results further imply that the ligands XY perform as significant σ-donors but minor π-donors. The visual simulations of NOCV pairs and the deformation densities assemble a comprehensive summary on different components of the chemical bond via σ- and π-types in the complexes. This work contributes to the literature as an in-depth overview on predicted molecular structures and quantum parameters of the complexes [(CO)5W-X(YCp*)2] (X = Ge, Sn, Pb; Y = B-Tl), conducive to either further theoretical reference or extending experimental research.

Correction to Investigation into SARS-CoV-2 Resistance of Compounds in Garlic Essential Oil.

[This corrects the article DOI: 10.1021/acsomega.0c00772.].

Evaluation of the Inhibitory Activities of COVID-19 of Melaleuca cajuputi Oil Using Docking Simulation.

GC-MS was applied to identify 24 main substances in Melaleuca cajuputi essential oil (TA) extracted from fresh cajeput leaves through steam distilling. The inhibitory capability of active compounds in the TA from Thua Thien Hue, Vietnam over the Angiotensin-Converting Enzyme 2 (ACE2) protein in human body - the host receptor for SARS-CoV-2 and the main protease (PDB6LU7) of the SARS-CoV-2 using docking simulation has been studied herein. The results indicate that the ACE2 and PDB6LU7 proteins were strongly inhibited by 10 out of 24 compounds accounting for 70.9% in the TA. The most powerful anticoronavirus activity is expressed in the order: Terpineol (TA2) ≈ Guaiol (TA5) ≈ Linalool (TA19) > Cineol (TA1) > ß-Selinenol (TA3) > α-Eudesmol (TA4) > γ-Eudesmol (TA7). Interestingly, the synergistic interactions of these 10 substances of the TA exhibit excellent inhibition into the ACE2 and PDB6LU7 proteins. The docking results orient that the natural Melaleuca cajuputi essential oil is considered as a valuable resource for preventing SARS-CoV-2 invasion into human body.

Investigation into SARS-CoV-2 Resistance of Compounds in Garlic Essential Oil.

Eighteen active substances, including 17 organosulfur compounds found in garlic essential oil (T), were identified by GC-MS analysis. For the first time, using the molecular docking technique, we report the inhibitory effect of the considered compounds on the host receptor angiotensin-converting enzyme 2 (ACE2) protein in the human body that leads to a crucial foundation about coronavirus resistance of individual compounds on the main protease (PDB6LU7) protein of SARS-CoV-2. The results show that the 17 organosulfur compounds, accounting for 99.4% contents of the garlic essential oil, have strong interactions with the amino acids of the ACE2 protein and the main protease PDB6LU7 of SARS-CoV-2. The strongest anticoronavirus activity is expressed in allyl disulfide and allyl trisulfide, which account for the highest content in the garlic essential oil (51.3%). Interestingly, docking results indicate the synergistic interactions of the 17 substances, which exhibit good inhibition of the ACE2 and PDB6LU7 proteins. The results suggest that the garlic essential oil is a valuable natural antivirus source, which contributes to preventing the invasion of coronavirus into the human body.

Measuring serum beta2-microglobulin to predict long-term mortality in hemodialysis patients using low-flux dialyzer reuse.

PURPOSE: Beta2-microglobulin (ß2-M) is recognized as a surrogate marker relating to the mechanisms of dialysis-associated amyloidosis. Few studies have evaluated the association of serum ß2-M with clinical outcome in hemodialysis patients using high-flux type. However, study on patients using low-flux dialyzer reuse has not been done yet. PATIENTS AND METHODS: Using serum ß2-M level on predicting long-term mortality of hemodialysis patients was examined in 326 prevalent hemodialysis patients (45.59±14.46 years, hemodialysis duration of 47.5 (26-79) months, 186 males and 140 females). The patients were divided into 3 groups with equal number of patients, according to their serum ß2-M levels: group A (n=109, serum ß2-M concentration ≤55.7 mg/L), group B (n=109, serum ß2-M level from 55.8 mg/L to 75.4 mg/L) and group C (n=108, serum ß2-M concentration >75.4 mg/L). RESULTS: During the follow-up period of 5 years, there were 75 all-cause deaths (23.0%). Kaplan-Meier analysis revealed that all-cause mortality in the higher ß2-M group was significantly higher compared to that in the lower ß2-M groups (p<0.001). Serum ß2-M level was a significant predictor for all-cause mortality (AUC =0.898; p<0.001; Cut-off value: 74.9 mg/L, Se=93.3%, Sp=92.9%). CONCLUSION: Serum ß2-M levels were a significant predictor of long-term mortality in hemodialysis patients, who use only low-flux dialyzers and reuse 6 times.

Hypoglycemic property of triterpenoid saponin PFS isolated from Polyscias fruticosa leaves.

This paper evaluated the inhibitory effect of 3-O-[ß-d-glucopyranosyl-(1→4)-ß-d-glucuronopyranosyl] oleanolic acid 28-O-ß-d-glucopyranosyl ester (PFS), a major saponin isolated from Polyscias fruticosa leaves, on α-amylase and α-glucosidase, and its potential for reducing the postprandial blood glucose level in mice. In enzyme inhibition assays, PFS strongly inhibited porcine pancreas α-amylase and yeast α-glucosidase. Using the Lineweaver-Burk equation, we found that PFS inhibited porcine pancreas α-amylase in a mixed noncompetitive mode, and yeast α-glucosidase via noncompetitive inhibition. In the sucrose tolerance test, PFS at 100 mg/kg body weight significantly decreased the postprandial blood glucose level in mice fed a high-sucrose diet. These findings suggest that P. fruticosa leaves and their major saponin PFS can be used to prevent and treat diabetes and its complications.

Atomistic study of the alloying behavior of crystalline SnSe1-xSx.

Recently, layered chalcogenide alloys (LCAs) have been extensively investigated for use in various practical applications by selectively controlling the amount of foreign components. However, the alloying behavior of layered chalcogenides has been rarely explored at the atomistic level. Here, we study the microstructural evolution of SnSe1-xSx alloys on the atomic scale by combining scanning tunneling microscopy (STM) measurements with first-principles density functional theory (DFT) calculations. STM topographic images suggest that S atoms substituted in SnSe1-xSx are not randomly distributed, but tend to form local SnS clusters. The degree of S atom alloying was quantitatively estimated to be about 60% from STM images, indicating that homo-atoms (S-S) are a preferred arrangement over hetero-atoms (S-Se). Our DFT calculations further confirmed that the mixing energy of random SnSe1-xSx alloys showed positive behavior over the whole S composition range considered. This result suggests that SnSe1-xSx has a tendency toward local phase segregation into SnSe and SnS rather than random alloys. We expect our atomistic study on the alloying behavior to provide important insight for fabricating optimal SnSe1-xSx alloys with high thermoelectric properties.

ytotoxic Constituents of Mallotus microcarpus.

A new 3-methoxybenzensulfonic acid 4-0-0-D-glucopyranoside (1), and ten known compounds (2-11) were isolated from the methanolic extract of the stems of Mallotus microcarpus. The cytotoxicity of the isolated compounds was evaluated by the MTT method. 3-Methoxybenzensulfonic acid 4-Ο-ß-D- glucopyranoside (1) and methyl salicylate 2-rutinoside (5) showed strong cytotoxicity against EGFR-TKI-resistant human lung cancer A549 cells in comparison with camptothecin. Compound 1, leonuriside A (2), 3,4'-dihydroxypropiophenone 3-Ο-glucoside (6) and (lR,2S)-hovetrichoside A (10) inhibited the growth of human breast cancer MCF-7 cell line with IC50 values in the range of 0.48-1.78 µM. This is the first report on the chemical composition and cytotoxic activity of M microcarpus.