Antibacterial activity and antibacterial mechanism of flavaspidic acid BB against Staphylococcus haemelyticus.

BACKGROUND: Staphylococcus haemolyticus (S. haemolyticus) is the main etiological factor in skin and soft tissue infections (SSTI). S. haemolyticus infections are an important concern worldwide, especially with the associated biofilms and drug resistance. Herein, we investigated the inhibitory effect of Flavaspidic acid BB obtained from plant extractions on clinical S. haemolyticus strains and their biofilms. Moreover, we predicted its ability to bind to the protein-binding site by molecular simulation. Since the combination of Hsp70 and RNase P synthase after molecular simulation with flavaspidic acid BB is relatively stable, enzyme-linked immunosorbent assay (ELISA) was used to investigate Hsp70 and RNase P synthase to verify the potential antimicrobial targets of flavaspidic acid BB. RESULTS: The minimum inhibitory concentrations (MIC) of flavaspidic acid BB on 16 clinical strains of S. haemolyticus was 5 ~ 480 µg/mL, and BB had a slightly higher inhibitory effect on the biofilm than MUP. The inhibitory effect of flavaspidic acid BB on biofilm formation was better with an increase in the concentration of BB. Molecular simulation verified its ability to bind to the protein-binding site. The combination of ELISA kits showed that flavaspidic acid BB promoted the activity of Hsp70 and inhibited the activity of RNase P, revealing that flavaspidic acid BB could effectively inhibit the utilization and re-synthesis of protein and tRNA synthesis, thus inhibiting bacterial growth and biofilm formation to a certain extent. CONCLUSIONS: This study could potentially provide a new prospect for the development of flavaspidic acid BB as an antibacterial agent for resistant strains.

Antibacterial and anti-biofilm activities of Disaspidin BB against Staphylococcus epidermidis.

Introduction: Staphylococcus epidermidis infections are an important concern in worldwide, especially when associated with biofilms, and resistance of this agent to many drugs makes the situation even worse. We investigated the inhibitory effect of Disaspidin BB obtained from plant extracts and purifications on clinical S. epidermidis strains and their biofilms, and preliminarily investigated its mechanism of of its anti-biofilm activity. Methods and Results: The broth dilution method was used to determine the minimum inhibitory concentrations (MIC) of Disaspidin BB on 11 clinical S. epidermidis strains (MIC value of 0.63 ~ 2.5 µg/ml). SEP-05 was found to be erythromycin-resistant (MIC value>8 µg/ml) and Disaspidin BB sensitive with an MIC value of 0.63 µg/ml. The time-kill curve assay indicated that the antibacterial activity of Disaspidin BB against SEP-05 with concentration dependence. The metabolic activity and total biomass of the drug-treated SEP-05 biofilm in each stage were significantly inhibited by the crystalline violet and XTT assay, and the scavenging effect of Disaspidin BB on SEP-05 biofilm was also confirmed by SEM observation. The results of real-time quantitative PCR showed that subinhibitory concentrations Disaspidin BB can inhibit biofilm formation by affecting the expression level of key genes (aap, atlE, icaA, luxS, recA) in SEP-05 biofilm formation. In addition, the content of polysaccharides, proteins and extracellular DNA in biofilm matrix after the intervention of Disaspidin BB was significantly reduced, and it was tentatively determined that the ability of SEP-05 biofilm formation and its stability were thus disturbed. Discussion: The results show that Disaspidin BB has promising antibacterial effect on erythromycin-resistant S. epidermidis and significant scavenging effect on its biofilm, which provides a theoretical basis for the further development of BB as a new drug for the treatment of skin infections caused by S. epidermidis.

Isoflavaspidic Acid PB Extracted from Dryopteris fragrans (L.) Schott Inhibits Trichophyton rubrum Growth via Membrane Permeability Alternation and Ergosterol Biosynthesis Disruption.

Isoflavaspidic acid PB (PB), a phloroglucinol derivative extracted from aerial parts of Dryopteris fragrans (L.) Schott, had antifungal activity against several dermatophytes. This study was aimed at exploring the antifungal mechanism of PB against Trichophyton rubrum (T. rubrum). The effectiveness of PB in inhibiting T. rubrum growth was detected by time-kill kinetics study and fungal biomass determination. Studies on the mechanism of action were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), sorbitol and ergosterol assay, nucleotide leakage measurement, and UPLC-based test and enzyme-linked immunosorbent assay. Fungicidal activity of PB was concentration- and time-dependent at 2 × MIC (MIC: 20 µg/mL) after 36 h. The total biomass of T. rubrum was reduced by 64.17%, 77.65%, and 84.71% in the presence of PB at 0.5 × MIC, 1 × MIC, and 2 × MIC, respectively. SEM analysis showed that PB changed mycelial morphology, such as shrinking, twisting, collapsing, and even flattening. TEM images of treated cells exhibited abnormal distributions of polysaccharide particles, plasmolysis, and cytoplasmic content degradation accompanied by plasmalemma disruption. There were no changes in the MIC of PB in the presence of sorbitol. However, the MIC values of PB were increased by 4-fold with exogenous ergosterol. At 4 h and 8 h, PB increased nucleotide leakage. Besides, ergosterol content in T. rubrum membrane treated with PB at 0.5 × MIC, 1 × MIC, and 2 × MIC was decreased by 9.58%, 15.31%, and 76.24%, respectively. There was a dose-dependent decrease in the squalene epoxidase (SE) activity. And the reduction in the sterol 14α-demethylase P450 (CYP51) activity was achieved after PB treatments at 1 × MIC and 2 × MIC. These results suggest that PB displays nonspecific action on the cell wall. The membrane damaging effects of PB were attributed to binding with ergosterol to increase membrane permeability and interfering ergosterol biosynthesis involved with the reduction of SE and CYP51 activities. Further study is needed to develop PB as a natural antifungal candidate for clinical use.

[Mechanism of Liangfu Pills in treatment of functional dyspepsia: based on network pharmacology and experimental verification].

This study aims to explore the potential mechanism of Liangfu Pills in the treatment of functional dyspepsia(FD) based on network pharmacology and molecular docking, and verify the mechanism by animal experiment. The active components of Liangfu Pills were screened from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and the targets of Liangfu Pills were predicted by SwissTargetPrediction. The targets of FD were retrieved from GeneCards. On this basis, the common targets of the disease and the pills were yielded and the protein interaction was retrieved based on STRING. The core targets were screened out, followed by Gene Oncology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis with DAVID. Finally, molecular docking was carried out with the help of AutoDock Tools to predict the binding degree between the effective components of Liangfu Pills and core targets. A total of 19 active components of Liangfu Pills and 591 FD-related targets were screened out by network pharmacology, of which 253 were common targets of the disease and the prescription. Liangfu Pills was mainly involved in the biological processes of response to drug, negative regulation of transcription, positive regulation of apoptotic process, and cell surface receptor signaling pathway, and the KEGG pathways of hypoxia-inducible factor-1(HIF-1) signaling pathway, serotonergic synapse, tumor necrosis factor(TNF) signaling pathway, cyclic adenosine monophosphate(cAMP) signaling pathway, calcium signal pathway, and inflammatory mediator regulation of transient receptor potential(TRP) channels. The results of molecular docking showed that the key active components of Liangfu Pills had certain binding activity to the targets mitogen-activated protein kinase 1(MAPK1), protein kinase B(AKT1), transient receptor potential cation channel subfamily V member 1(TRPV1), 5-hydroxytryptamine receptor 1 A(HTR1 A), and 5-hydroxytryptamine receptor 2 A(HTR2 A). FD was induced in rats, and then Liangfu Pills was given to FD rats for 7 days. The results showed that Liangfu Pills could significantly relieve the symptoms of FD rats, significantly increase the expression of 5-hydroxytryptamine(5-HT), and down-regulate the expression of TRPV1. Through network pharmacology, molecular docking, and experimental verification, this study proved that Liangfu Pills improved FD through multiple components and multiple targets. The result lays a basis for further research on the mechanism and clinical application of Liangfu Pills in the treatment of FD.

Flavaspidic acid BB combined with mupirocin improves its anti-bacterial and anti-biofilm activities against Staphylococcus epidermidis.

BACKGROUND: The increase in drug-resistant opportunistic pathogenic bacteria, especially of antibiotic-resistant Staphylococcus epidermidis (S. epidermidis), has led to difficulties in the treatment of skin and soft tissue infections (SSTI). The major reason for bacterial resistance is the formation of bacterial biofilm. Here, we report a promising combination therapy of flavaspidic acid BB (BB) and mupirocin, which can effectively eradicate the biofilm of S. epidermidis and eliminate its drug resistance. RESULT: The susceptibility test showed that the combination of BB and mupirocin has good antibacterial and antibiofilm activities, and the fractional inhibitory concentration index (FICI) of BB combined with mupirocin was 0.51 ± 0.00 ~ 0.75 ± 0.05, showing synergistic effect. Moreover, the time-kill curve assay results indicated that the combination of drugs can effectively inhibit the planktonic S. epidermidis. After drugs treatment, the drug-combination showed significantly inhibitory effects on the metabolic activity and total biomass in each stage of biofilm formation. The synergistic effect is likely related to the adhesion between bacteria, which is confirmed by field emission scanning electron microscope. And the expression level of aap, sarA and agrA genes were detected by real-time quantitative PCR (qRT-PCR). CONCLUSION: Our study provides the experimental data for the use of BB for the clinical treatment of skin infections and further demonstrate the potential of BB as a novel biofilm inhibitor.

Anoectochilus roxburghii flavonoids extract ameliorated the memory decline and reduced neuron apoptosis via modulating SIRT1 signaling pathway in senescent mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Anoectochilus roxburghii (A. roxburghii) is a precious herb and folk medicine in many Asian countries. It has been used traditionally to treat diabetes, etc., and also used as a dietary therapy to delay senescence. AIM OF THE STUDY: This study was to evaluate the neuroprotective effects of A. roxburghii flavonoids extract (ARF) and whether its effects were due to the regulation of SIRT1 signaling pathway in senescent mice and in D-galactose (D-gal) induced aging in SH-SY5Y cells. MATERIALS AND METHODS: 18-month-old mice were randomly divided into senescent model, low-dose ARF, high-dose ARF and vitamin E group. 2-Month-old mice were as a control group. After 8 weeks treatment, Morris water maze (MWM) was performed. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), monoamine oxidase (MAO) and acetylcholinesterase (ACh-E) in the cortex were determined. Hippocampus morphologic changes were observed with haematoxylin and eosin (H&E), Nissl, senescence-associated-galactosidase (SA-ß-gal) and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) staining. Apoptosis-related molecular expressions in the hippocampus were performed by western blotting. Furthermore, after stimulated by EX527 (a SIRT1 inhibitor), the SIRT1-dependent neuroprotective effects of ARF were determined by measuring SRIT1 and p53 expression in SH-SY5Y aging cells induced by D-gal. RESULTS: ARF could significantly ameliorate memory decline in senescent mice and reduce the generations of ROS, MDA and the activities of MAO and ACh-E, while increasing SOD activities in the cortex of aging mice. ARF obviously improved hippocampus pathological alterations, increased the number of Nissl bodies, while reducing senescent and apoptotic cells in senescent mice hippocampus. Further, ARF positively regulated SIRT1 expression, and reduced apoptosis-related molecules p53, p21 and Caspase-3 expression, while increasing the ratio of Bcl-2/Bax. In D-gal-induced SH-SY5Y cells, the effects of ARF on SIRT1 and p53, and the ability of scavenging ROS were mostly abolished after incubation with the EX527. CONCLUSIONS: ARF, in a SIRT1-dependent manner, exerted neuroprotection via modulating SIRT1/p53 signaling pathway against memory decline and apoptosis due to age-induced oxidative stress damage in senescent mice.

[A new phloroglucinol from Dryopteris fragrans and its antibacterial activity in vitro].

A new phloroglucinol was isolated from 50% ethanol extract of Dryopteris fragrans by silica gel column chromatography, Sephadex LH-20 gel column chromatography, thin-layer chromatography(TLC), and preparative liquid column chromatography. On the basis of MS, ~1H-NMR, ~(13)C-NMR, and reference materials, compound 1 was identified as 2,5-cyclohexadien-1-one, 2-{[2,6-dihydroxy-4-methoxy-3-methyl-5-(1-isobutyl)phenyl]methyl}-3,5-dihydroxy-4,4-dimethyl-6-(1-oxobutyl)(1), and named disaspidin BB. Compound 1 was evaluated for its antibacterial activity. The experimental results showed that compared with the commonly used topical antibiotics erythromycin or mupirocin, disaspidin BB exhibited significant antibacterial activities against Staphylococcus epidermidis(SEP), S. haemolyticus(SHA), and methicillin-resistant S. aureus(MRSA)(P<0.05). Additionally, disaspidin BB was sensitive to ceftazidime-resistant SEP1-SEP4, SHA5-SHA7, MRSA8, and MRSA9. The MIC values of disaspidin BB against SEP and SHA were 1.67-2.71 µg·mL~(-1) and 10.00-33.33 µg·mL~(-1) respectively. Disaspidin BB has good antibacterial activities and deserves development as a new anti-infective drug for external use.

Data Mining Study on Prescription Patterns of Different Dosage Forms of Chinese Herbal Medicines for Treating and Improving Immune-Inflammatory Indices in Patients with Rheumatoid Arthritis.

OBJECTIVE: To explore the prescription patterns of different dosage forms of Chinese herbal medicines (CHMs) for the treatment of rheumatoid arthritis (RA) and their effects on immune-inflammatory indices. METHODS: Clinical data were collected from patients with RA in 4 hospitals (3 Class A comprehensive hospitals and 1 Class B comprehensive hospital) in Anhui Province, China, from August 2012 to June 2018 via the electronic medical record gathering system. Following extraction of prescription information, each prescribed herb was quantified and standardized according to the knowledge base to establish a database of RA treatment formulae. The medical records were divided into the granules group and decoction pieces group. Core herbs and their combination patterns were obtained from the two groups of cases using Liquorice software. Changes in immune-inflammatory and hepatic and renal function indices were compared between the two groups using SPSS 23.0 software. The Aprior module of SPSS Clementine 11.1 software was applied to analyse the correlation between CHMs and improvement in indices. Finally, the ORACLE 10 g tool was used to evaluate the random walk model of the immune-inflammatory indices between the two groups. RESULTS: (1) We retrospectively analysed 35,898 prescriptions for 6,829 patients with RA who received CHM treatment. There were 3,816 patients in the granules group and 3,013 in the decoction pieces group. (2) The core herbs were Pi (Spleen)-strengthening and dampness-resolving drugs, blood-activating and stasis-resolving drugs, wind/dampness-dispelling drugs and heat-clearing and detoxifying drugs. (3) Both dosage forms could improve immune-inflammatory indices in RA patients, with similar efficacy and no influence on hepatic or renal function. (4) Herba Siegesbeckiae and Oldenlandia had a stronger association with immune-inflammatory indices in the two groups. (5) The immune-inflammatory indices showed obvious improvement after treatment with granules and decoction pieces of CHMs, and there were long range correlations between the comprehensive evaluation indices and interventions. CONCLUSIONS: The principal CHM treatment methods for RA in four hospitals in Anhui Province are strengthening Pi and resolving dampness, activating blood and resolving stasis, dispelling wind/dampness and clearing heat. Granules and decoction pieces of CHMs have similar efficacy in improving immune-inflammatory indices in RA patients and could be used as treatment options for RA.

Knockdown of LncRNA SNHG1 Suppresses Corneal Angiogenesis by the Regulation of miR-195-5p/VEGF-A.

LncRNA SNHG1 (SNHG1) has been widely studied as the causative factor of angiogenesis and proliferative agent in gastric, lung, cervical, and hepatocellular carcinomas. However, its significance of angiogenesis and progression of corneal neovascularization (CRNV) is least understood. This study focuses on the molecular mechanisms followed by SNHG1 to establish CRNV and its angiogenesis. Bioinformatics analysis to identify potential miRNA targets of SNHG1 and vascular endothelial growth factor A (VEGF-A) was conducted using StarBase and was subsequently confirmed by the luciferase reporter assay. Relative quantitative expression of SNHG1 in human umbilical vein endothelial cells (HUVECs) was detected through qRT-PCR and western blot analysis. Cell proliferation was detected through CCK-8 assay, whereas migratory abilities of the cells were determined with transwell assay. A capillary-like tube formation assay was performed to detect the tube formation ability of the cells. Following this, relative expression of miR-195-5p and VEGF-A was determined through qRT-PCR and western blot analysis. Results from the experiments manifested upregulated levels of SNHG1 and VEGF-A in HUVECs and CRNV tissues as compared with the control group, whereas downregulated levels of miR-195-5p were measured in the CRNV tissues and HUVECs, suggesting the negative correlation between lncRNA and miRNA. Overexpressed vascular endothelial growth factor promoted cell proliferation and tube formation; however, its silencing leads to inhibition in angiogenesis and proliferation. Potential binding sites of SNHG1 showed miR-195-5p as its direct target and SNHG1 as a sponge for this miRNA. Knockdown and downregulated levels of SNHG1 showed a notable decrease and inhibition in angiogenesis and migration of CRNV cells. The study showed that SNHG1 inhibition significantly reduced cell proliferation, migration, and tube formation in HUVECs transfect with lncRNA SNHG1. Mechanistic insights into the SNHG1 showed that SNHG1 acts as a sponge for miR-195-5p and upregulates the levels of VEGF-A.

A novel alkaloid glycoside isolated from Atalantia buxifolia.

From the dried root and rhizomes of Atalantia buxifolia afford 11 compounds, one new compound 1 and ten known compounds 2-11 were isolated and identified. The novel compound 1 was alkaloid glycoside. Its mother nuclear was the acridone, which was relatively rare. The structure of compound 1 was established identified by spectrum and elucidated as ß-D-Glu-4,5-dimethoxy-1,6-dihydroxy-10-methyl-acridone. The compound 1 enriched the compound library and laid the material foundation for the subsequent study of pharmacological activities.

The effect of isoflavaspidic acid PB extracted from Dryopteris fragrans (L.) Schott on planktonic and biofilm growth of dermatophytes and the possible mechanism of antibiofilm.

ETHNOPHARMACOLOGICAL RELEVANCE: Dryopteris fragrans (L.) Schott (D. fragrans), a deciduous perennial herb, has been traditionally used for treatment of various skin diseases in Heilongjiang province of China for many years. Phloroglucinol derivatives extracted from D. fragrans were the most effective fraction against dermatophytes. Isoflavaspidic acid PB is a typically phloroglucinol derivative which extracted from D. fragrans and has been reported to exert anti-fungal activities against several dermatophytes. AIM OF THE STUDY: This study aimed to evaluate anti-fungal and anti-biofilm activity of isoflavaspidic acid PB on planktonic and biofilm growth of dermatophytes and explore possible mechanisms of anti-biofilm. MATERIALS AND METHODS: Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of isoflavaspidic acid PB against 25 isolates of dermatophytes were determined by the Clinical and Laboratory Standards Institute (CLSI) M38-A2 method. The effects of isoflavaspidic acid PB on dermatophytes biofilm formation and pre-formed biofilm were assessed by 2.3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[carbonyl (phenylamino)]-2H-tetrazolium hydroxide (XTT) assay. Morphology of mature biofilm were observed by Scanning Electron Microscope (SEM). Biomass, exopolysaccharide and ergosterol content of mature biofilm were analyzed by gravimetric analysis, anthranone sulfuric acid method and Ultra Performance Liquid Chromatography (UPLC) assay respectively. RESULT: The MIC and MFC ranges of isoflavaspidic acid PB against 25 isolates of dermatophytes were 20-80 µg/mL and 40-80 µg/mL respectively. Isoflavaspidic acid PB (2 MIC) inhibited not only Trichophyton biofilm formation (54.8% ∼ 81.2%) but also the metabolic activity of mature biofilm (20.7% ∼ 44.2%). The result of SEM showed that isoflavaspidic acid PB (8 MIC) could destroy the morphology of hyphae seriously. Comparing with control group, biomass, exopolysaccharide and ergosterol content of the mature biofilm under isoflavaspidic acid PB (8 MIC) were significantly decreased (P < 0.01). CONCLUSION: Isoflavaspidic acid PB had anti-fungal and fungicidal activities against dermatophytes. Isoflavaspidic acid PB could inhibit the biofilm of Trichophyton. The mechanism might be related to the decline of the biofilm biomass, exopolysaccharide and ergosterol content. These results showed that isoflavaspidic acid PB could be explored for promising anti-biofilm drugs.

Preparation, Antidermatophyte Activity, and Mechanism of Methylphloroglucinol Derivatives.

In this study a variety of phloroglucinols were isolated from the plant, and the activity experiment showed that the phloroglucinols had strong antifungal activity, especially methylphloroglucinol derivatives such as aspidin PB, dryofragin, aspidinol, aspidin BB, aspidin AB, and albicanol, in which the hydroxyl group of methylphloroglucinol is the active group of compounds, and C-2 or C-6 is the active site. The introduction of different groups in this position could change the properties and bioactivity of the compounds. In this study, different functional groups were introduced to the structure of methylphloroglucinol to obtain methylphloroglucinol derivatives that were synthesized, and antidermatophyte activities on Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, and Gypsum microspore bacteria were evaluated. Molecular docking verified its ability to combine the protein binding site. The antidermatophyte mechanism of compounds on cytochrome P450 sterol 14a-demethylase, squalene epoxidase, and ß-1,3-glucan synthase was investigated by the enzyme-linked immunosorbent assay. The results showed that compounds had an inhibitory effect on four kinds of common dermatophytes in varying degrees, in which compound g had the strongest activities, the binding mode of methylphloroglucinol and its derivatives were similar to those of three enzymes, and compounds e and g had significant effects on the activity of the three enzymes, and compound g had a slightly stronger effect than the blank group. Compounds e and g also had a significant effect on the ergosterol synthesis of M. canis. This study could supply some antidermatophyte leading structure and possible mechanism for studying and developing new antifungal agents.

Antifungal Agents: Design, Synthesis, Antifungal Activity and Molecular Docking of Phloroglucinol Derivatives.

Pseudoaspidinol is a phloroglucinol derivative with Antifungal activity and is a major active component of Dryopteris fragrans. In our previous work, we studied the total synthesis of pseudoaspidinol belonging to a phloroglucinol derivative and investigated its antifungal activity as well as its intermediates. However, the results showed these compounds have low antifungal activity. In this study, in order to increase antifungal activities of phloroglucinol derivatives, we introduced antifungal pharmacophore allylamine into the methylphloroglucinol. Meanwhile, we remained C1⁻C4 acyl group in C-6 position of methylphloroglucinol using pseudoaspidinol as the lead compound to obtain novel phloroglucinol derivatives, synthesized 17 compounds, and evaluated antifungal activities on Trichophyton rubrum and Trichophyton mentagrophytes in vitro. Molecular docking verified their ability to combine the protein binding site. The results indicated that most of the compounds had strong antifungal activity, in which compound 17 were found to be the most active on Trichophyton rubrum with Minimum Inhibitory Concentration (MIC) of 3.05 µg/mL and of Trichophyton mentagrophytes with MIC of 5.13 µg/mL. Docking results showed that compounds had a nice combination with the protein binding site. These researches could lay the foundation for developing antifungal agents of clinical value.

Analysis of chemical composition and in vitro antidermatophyte activity of ethanol extracts of Dryopteris fragrans (L.) Schott.

ETHNOPHARMACOLOGICAL RELEVANCE: Dryopteris fragrans (L.) Schott is a deciduous perennial herb, which has been used traditionally for treatment of ringworm infections and others skin diseases in the north of China. AIM OF THE STUDY: To characterize the chemical composition, evaluate the antifungal activity and explore possible mechanisms about action of ethanol extracts of D. fragrans. MATERIALS AND METHODS: The chemical components in the ethanol extracts of D. fragrans were detected by high-performance liquid chromatography coupled with electrospray ionization and quadruple time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS/MS). The minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of the ethanol extracts of D. fragrans were determined by the Clinical and Laboratory Standards Institute (CLSI) M38-A2 method against 62 isolates of dermatophytes. The kinetics of fungal kill, synergy testing by checkerboard dilution and quantitation of sterol by ultra-performance liquid chromatography (UPLC) on Trichophyton rubrum and Trichophyton mentagrophytes were also investigated. RESULTS: Fourteen derivatives of phloroglucinol were identified in the ethanol extracts of D. fragrans. The MIC of the ethanol extracts of D. fragrans ranged from 0.059 to 3.780 mg/mL while MFC ranged from 0.118 to 3.780 mg/mL. The ethanol extracts of D. fragrans exerted fungicidal activity after 12 h of incubation against Trichophyton rubrum while it required 36 h of incubation against Trichophyton mentagrophytes at concentrations of 8 × MIC. In synergy testing, the interaction between miconazole (MCZ) and terbinafine (TBF) with the ethanol extracts of D. fragrans proved to be indifferent by testing fractional inhibitory concentration (FIC) values. Sterol in samples of fungal cells treated with the ethanol extracts of D. fragrans was significantly reduced. CONCLUSIONS: The ethanol extracts of D. fragrans had antifungal and fungicidal activity against dermatophytes and was likely a strain-dependent fungicidal agent. Interaction between drugs was indifferent on tested isolates. The inhibition of ergosterol biosynthesis was one of the antifungal mechanisms of the ethanol extracts of D. fragrans. These results showed that the ethanol extracts of D. fragrans could be explored for promising antifungal drugs. Dozens of phloroglucinol derivatives may contribute to high antifungal activity of the ethanol extracts of D. fragrans.

Germacrone derivatives: synthesis, biological activity, molecular docking studies and molecular dynamics simulations.

Germacrone is one of the major bioactive components in the Curcuma zedoaria oil product, which is extracted from Curcuma zedoaria Roscoe, known as zedoary. The present study designed some novel germacrone derivatives based on combination principles, synthesized these compounds, and investigated their inhibitions on Bel-7402, HepG2, A549 and HeLa cells. Meanwhile, the study evaluated inhibitions of these derivatives on c-Met kinase, which has been detected in a number of cancers. The results suggested that the majority of the compounds showed stronger inhibitory effect on cancers and c-Met kinase than germacrone. Furthermore, our docking experiments analyzed the results and explained the molecular mechanism. Molecular dynamics simulations were then applied to perform further evaluation of the binding stabilities between compounds and their receptors.

[Studies on structure characteristic of polysaccharide P1A from Dicliptera chinensis].

The chemical structures of P1 A was identified by complete acid hydrolysis, partial acid hydrolysis, periodate oxidation-Smith degradation, methylation analysis, IR and NMR. The results showed that P1 A had a backbone consisting rhamnose, mannose, glucose and galactose. The side chain possessed arabinose and xylose. 1-->, 1-->6 and non-reducing terminal linkages existed in polysaccharide P1A, but there are doubling amount of 1-->2 and 1-->4 linkages. Oxidable linkage of P1 A accounted for 45%, and inoxidable linkage of P1A accounted for 55%. Mannose, glucose and galactose were mainly linked by 1-->2 linkage. Rhamnose, arabinose and xylose were mainly linked by 1-->2 and 1-->4 linkages. PlA contained beta-Glc(1,6)-,beta-Gal(1,3)-,beta-Man(1,4)-beta-Rha,-Glc(1,4)-, Glc(1)-,-Gal(1,4)- and Man(1)-.

Antinociceptive and anti-inflammatory activities of Schefflera octophylla extracts.

ETHNOPHARMACOLOGICAL RELEVANCE: Schefflera octophylla (Lour.) Harms, a traditional Chinese herb mainly distributed in Southeast Asia, is extensively prescribed to alleviate pain and treat rheumatoid arthritis (RA), influenza, throat swelling, pain, etc. In this paper, the antinociceptive and anti-inflammatory activities of the ethanol extract and its five different polar fractions of this plant were evaluated. Furthermore, the anti-rheumatoid arthritis activity of the ethanol extract and its active fraction (CHCl3 fraction) were evaluated. And the chemical constituents of the CHCl3 active fraction displayed significant antinociceptive and anti-inflammatory activities were investigated. MATERIALS AND METHODS: Antinociceptive and anti-inflammatory activities were investigated by hot plate test, acetic acid-induced abdominal writhing test and formalin test, xylene-induced ear edema test. The anti-rheumatoid arthritis activity was evaluated through the model of adjuvant-induced arthritis (AA) in rats, paw swelling, pain response, arthritis index and histopathological changes of ankle, the levels of TNF-α, IL-1ß, IL-6 and rheumatoid factor (RF) of rats were detected. The chemical constituents of the CHCl3 fraction were isolated using chromatographic techniques. Their structures were elucidated by spectroscopic data analysis. RESULTS: The results showed that the ethanol extract of S. octophylla has significant dose-dependent anti-inflammatory and antinociceptive activities. And its five different polar fractions especially the CHCl3 fraction significantly inhibited the abdominal writhing induced by acetic acid and ear edema induced by xylene, also increased pain threshold in hot plate test in 120 min and reduced ticking times in formalin test. The ethanol extract of S. octophylla and the CHCl3 fraction demonstrated an anti-RA effect in a dose-dependent manner. The levels of TNF-α, IL-1ß and IL-6 in ethanol extract (600 mg/kg) and CHCl3 fraction (300 mg/kg) groups were significantly lower than those of the model group. The chemical constituents study of the CHCl3 fraction from S. octophylla led to six triterpenoids which were identified as taraxerone (1), 3-epi-taraxerol (2), aleuritolic acid (3), 3-oxofriedelan-28-oic acid (4), 3ß,19α -dihydroxy-urs-12-ene- 24,28-dioic acid (5) and asiatic acid (6). Compounds 1-5 were obtained from this plant for the first time. CONCLUSION: This study proved the antinociceptive, anti-inflammatory and anti-rheumatoid arthritis activities of S. octophylla. Triterpenoids obtained from its CHCl3 fraction may be responsible for those activities. These results could support the fact that S. octophylla is used traditionally to cure inflammatory and pain diseases.

Four new pentasaccharide resin glycosides from Ipomoea cairica with strong α-glucosidase inhibitory activity.

Six pentasaccharide resin glycosides from Ipomoea cairica, including four new acylated pentasaccharide resin glycosides, namely cairicoside I-IV (1-4) and the two known compounds cairicoside A (5) and cairicoside C (6), were isolated from the aerial parts of Ipomoea cairica. Their structures were established by a combination of spectroscopic, including two dimensional (2D) NMR and chemical methods. The core of the six compounds was simonic acid A, and they were esterfied the same sites, just differing in the substituent groups. The lactonization site of the aglycone was bonded to the second saccharide moiety at C-2 in 1-4, and at C-3 in 5-6. Compounds 1 and 5, 4 and 6 were two pairs of isomers. The absolute configuration of the aglycone in 1-6 which was (11S)-hydroxyhexadecanoic acid (jalapinolic acid) was established by Mosher's method. Compounds 1-4 have been evaluated for inhibitory activity against α-glucosidase, which all showed inhibitory activities.

Resonance frequency and mass identification of zeptogram-scale nanosensor based on the nonlocal beam theory.

Free vibration and mass detection of carbon nanotube-based sensors are studied in this paper. Since the mechanical properties of carbon nanotubes possess a size effect, the nonlocal beam model is used to characterize flexural vibration of nanosensors carrying a concentrated nanoparticle, where the size effect is reflected by a nonlocal parameter. For nanocantilever or bridged sensor, frequency equations are derived when a nanoparticle is carried at the free end or the middle, respectively. Exact resonance frequencies are numerically determined for clamped-free, simply-supported, and clamped-clamped resonators. Alternative approximations of fundamental frequency are given in closed form within the relative error less than 0.4%, 0.6%, and 1.4% for cantilever, simply-supported, and bridged sensors, respectively. Mass identification formulae are derived in terms of the frequency shift. Identified masses via the present approach coincide with those using the molecular mechanics approach and reach as low as 10(-24)kg. The obtained results indicate that the nonlocal effect decreases the resonance frequency except for the fundamental frequency of nanocantilever sensor. These results are helpful to the design of micro/nanomechanical zeptogram-scale biosensor.

[Research status of natural compounds combine with antifungal agents against drug-resistent Candida albicans].

To against the emergence of drug-resistent candidiasis, the studys of synergism of natural compounds combine with antifungal agents in vitro showed a continuous growth in recent years. The paper reviewed recent progresses to compare the synergetic effect by FICI method, and to conclude the synergetic mechanisms which have been confirmed as a reference for futher study.