Three stilbenes from pigeon pea with promising anti-methicillin-resistant Staphylococcus aureus biofilm formation activity.

Cajaninstilbene acid (CSA), longistylin A (LLA), and longistylin C (LLC) are three characteristic stilbenes isolated from pigeon pea. The objective of this study was to evaluate the antibacterial activity of these stilbenes against Staphylococcus aureus and even methicillin-resistant Staphylococcus aureus (MRSA) and test the possibility of inhibiting biofilm formation. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these stilbenes were evaluated. And the results showed that LLA was most effective against tested strains with MIC and MBC values of 1.56 µg/mL followed by LLC with MIC and MBC values of 3.12 µg/mL and 6.25 µg/mL as well as CSA with MIC and MBC values of 6.25 µg/mL and 6.25-12.5 µg/mL. Through growth curve and cytotoxicity analysis, the concentrations of these stilbenes were determined to be set at their respective 1/4 MIC in the follow-up research. In an anti-biofilm formation assay, these stilbenes were found to be effectively inhibited bacterial proliferation, biofilm formation, and key gene expressions related to the adhesion and virulence of MRSA. It is the first time that the anti-S. aureus and MRSA activities of the three stilbenes have been systematically reported. Conclusively, these findings provide insight into the anti-MRSA mechanism of stilbenes from pigeon pea, indicating these compounds may be used as antimicrobial agents or additives for food with health functions, and contribute to the development as well as application of pigeon pea in food science.

Euryachincoside, a Novel Phenolic Glycoside with Anti-Hepatic Fibrosis Activity from Eurya chinensis.

Eurya chinensis has been recorded as a folk medicine traditionally used for treatment of a variety of symptoms. However, the phytochemical and pharmacological investigations of this plant are still scarce. A novel phenolic glycoside named Euryachincoside (ECS) was isolated by chromatographic separation from E. chinensis, and its chemical structure was identified by analysis of HRMS and NMR data. Its anti-hepatic fibrosis effects were evaluated in both HSC-T6 (rat hepatic stellate cells) and carbon tetrachloride (CCl4)-induced mice with Silybin (SLB) as the positive control. In an in vitro study, ECS showed little cytotoxicity and inhibited transforming growth factor-beta (TGF-ß)-induced Collagen I (Col1) along with alpha-smooth muscle actin (α-SMA) expressions in HSC-T6. An in vivo study suggested ECS significantly ameliorated hepatic injury, secretions of inflammatory cytokines, and collagen depositions. Moreover, ECS markedly mediated Smad2/3, nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways both in vitro and vivo. These present findings confirmed that ECS is a novel phenolic glycoside from E. chinensis with promising curative effects on hepatic fibrosis, and its mechanisms may include decreasing extracellular matrix accumulation, reducing inflammation and attenuating free radicals via Smad2/3, NF-κB and Nrf2 signaling pathways, which may shed light on the exploration of more effective phenolic glycoside-based anti-fibrotic agents.

Two new withanolides from the whole plants of Physalis peruviana.

Two new withaphysalin-type withanolides (18-O-ethylwithaphysalin R and 5-O-ethylphysaminimin C, 1 and 2), along with twelve known withanolides (3-14), were purified and identified from Physalis peruviana L. The chemical structures of these new isolates were elucidated through analyzing spectroscopic and HRESIMS data. All the obtained metabolites were appraised for their potential antiproliferative activity against the human breast cancer cell line MCF-7. Compound 7 was discovered to exhibit potent activity with an IC50 value of 3.51 µM and compounds 2, 6 and 14 showed weak cytotoxic effect.

Versatile Biocatalytic C(sp3 )-H Oxyfunctionalization for the Site- Selective and Stereodivergent Synthesis of α- and ß-Hydroxy Acids.

C(sp3 )-H oxyfunctionalization, the insertion of an O-atom into C(sp3 )-H bonds, streamlines the synthesis of complex molecules from easily accessible precursors and represents one of the most challenging tasks in organic chemistry with regard to site and stereoselectivity. Biocatalytic C(sp3 )-H oxyfunctionalization has the potential to overcome limitations inherent to small-molecule-mediated approaches by delivering catalyst-controlled selectivity. Through enzyme repurposing and activity profiling of natural variants, we have developed a subfamily of α-ketoglutarate-dependent iron dioxygenases that catalyze the site- and stereodivergent oxyfunctionalization of secondary and tertiary C(sp3 )-H bonds, providing concise synthetic routes towards four types of 92 α- and ß-hydroxy acids with high efficiency and selectivity. This method provides a biocatalytic approach for the production of valuable but synthetically challenging chiral hydroxy acid building blocks.

A Review on the Phytochemical and Pharmacological Properties of Rosa laevigata: A Medicinal and Edible Plant.

Rosa laevigata Michx., a medicinal and edible plant in China, has exerted a variety of medicinal values and health benefits. This present review aims to achieve a comprehensive and up-to-date investigation in the phytochemistry and pharmacology of R. laevigata. According to these findings in the literature, approximately 123 chemical ingredients covering triterpenoids, flavonoids, tannis, lignans and polysaccharides, have been characterized from various parts of this species. Among these isolates, 77 triterpenoids have been isolated and thus regarded as the primary and characteristic substance. Based on the chemical structures, most of the obtained triterpenoids can be classified into polyhydroxy triterpenoids and readily divided into four categories: ursane-type, oleanane-type, lupinane-type, as well as seco-triterpenoids. The crude extracts and the purified compounds have demonstrated various pharmacological effects in vitro and in vivo, such as antioxidant activity, immunomodulatory effect, anti-inflammatory effect, liver protection, kidney protection, cardiovascular protection, neuroprotective effect and improvement of diabetic cataract. Noticeably, these pharmacological results of R. laevigata provide evidences for its traditional uses. In addition, these different chemical ingredients existing in the title plant may have synergistic effects. In conclusion, the chemical profiles, including ingredients and structures, together with the modern pharmacological properties have been adequately summarized. These evidences have revealed this plant to be a valuable source for therapeutic foodstuff and more attention should be paid to a better utilization of this plant.

Callistemonols A and B, Potent Antimicrobial Acylphloroglucinol Derivatives with Unusual Carbon Skeletons from Callistemon viminalis.

A phytochemical investigation on the leaves of Callistemon viminalis resulted in the isolation of two unusual compounds, callistemonols A (1) and B (2). Callistemonol A (1) possesses a novel skeleton of a furan ring fusing both an α,ß-triketone and a phloroglucinol unit, while callistemonol B (2) is an acylphloroglucinol derivative featuring two methyl substituents on a five-membered ring and an isovaleryl side chain. Their structures were fully characterized on the basis of extensive spectroscopic analysis, including 1D and 2D NMR parameters, as well as the IR and HRESIMS data. Callistemonol A (1) represents an example of a natural dibenzofuran with two phenyl moieties, and a plausible biogenetic pathway to generate this novel dibenzofuran through a C-C bond-forming radical SAM enzyme is proposed. Moreover, antimicrobial assays, in conjunction with time-killing and biophysical studies, revealed that 1 and 2 exert potent bactericidal activities against a panel of methicillin-resistant pathogenic microbes.

Rosanortriterpene C, a 3,24-Dinor-2,4-seco-ursane Triterpene from the Fruits of Rosa laevigata var. leiocapus.

One new 3,24-dinor-2,4-seco-ursane triterpene, rosanortriterpene C (1), together with four known compounds including 24-norursane-type nortriterpenes (2-3), 24-noroleanane-type nortriterpene (4), ursane-type triterpene (5), was isolated from the fruits of Rosa laevigata var. leiocapus. The new structure was elucidated through comprehensive spectroscopic analysis, including one dimensional (1D) and 2D NMR data, as well as electrospray ionization high resolution (HR-ESI) MS and IR spectrometry. Compounds 1-5 showed moderate anti-inflammatory activities against the production of nitric oxide (NO) in RAW264.7 cells stimulated by lipopolysaccharide (LPS) with IC50 values of 10.35 ± 0.92, 14.28 ± 1.20, 5.04 ± 1.43, 29.29 ± 3.64, and 14.37 ± 0.59 µM, respectively.

Public Awareness of HIV Pre-Exposure Prophylaxis in Durham, North Carolina: Results of a Community Survey.

BACKGROUND Adoption of HIV pre-exposure prophylaxis (PrEP) remains limited among populations at greatest risk for HIV acquisition. This study aims to assess awareness of PrEP among individuals in Durham, North Carolina, which has one of the highest rates of HIV diagnoses in the state.METHOD In 2015-2016, we administered a survey including questions to assess PrEP awareness to individuals at multiple venues throughout Durham, North Carolina.RESULTS A total of 139 respondents were surveyed. The majority were male (66%) and black/African American (75%); 21% were Hispanic/Latino. There were an estimated 53 men who have sex with men (MSM), of which 18 (33%) were black MSM M 24 years of age. Overall, only 53/138 (38%) respondents were aware of PrEP. Awareness was reported among 33/52 (63%) MSM respondents, 29/46 (63%) black MSM, and 10/17 (59%) black MSM M 24 years of age. In multivariate analysis, non-heterosexual orientation, health-insured status, and prior HIV testing were significantly associated with PrEP awareness. Ninety-four (69%) of 137 respondents reported prior HIV testing.LIMITATIONS Limitations include non-random sampling and limited sample size. Further research needs to be done in other areas of North Carolina, and assessment of PrEP acceptability and uptake needs to be performed.CONCLUSION This study reveals low overall awareness of PrEP in Durham, North Carolina, indicating that expanded outreach is necessary to increase public awareness and encourage adoption of PrEP among all demographics at risk for HIV.

An educational initiative in response to identified PrEP prescribing needs among PCPs in the Southern U.S.

Pre-exposure prophylaxis (PrEP) is an effective HIV prevention method, but many primary care physicians (PCPs) have not incorporated PrEP into practice. While PrEP may be a key strategy to reducing high HIV transmission rates in the southern US, knowledge about PrEP prescribing patterns among PCPs in this region is lacking. An online survey was sent to a large network of PCPs at an academic medical center in North Carolina in October 2015. The survey was repeated in September 2016, after an educational intervention that included on-site trainings at 14 PCP offices. Chi-square tests were used to compare PrEP prescribing patterns among providers. The initial survey was sent to 389 PCPs, with 115 (30%) responding. Of these, 78% reported seeing men who have sex with men (MSM). Only 17% had prescribed PrEP. The most frequently identified barrier was lack of knowledge (60%). When the survey was repeated after the educational initiative, 79 PCPs (20%) responded. Of these, 90% reported seeing MSM, and 35% had prescribed PrEP. PCPs who had attended a training were more likely to have prescribed PrEP (OR 4.84, CI 1.77-13.21). In conclusion, PrEP prescribing among PCPs in the southern US is low. A survey among PCPs identified lack of knowledge as a barrier to prescribing, motivating an institutional-wide educational campaign in response. Further efforts are needed to continue to raise awareness and educate PCPs in the South about PrEP.

Three new kavalactone dimers from Piper methysticum (kava).

Three new dimeric kavalactones, designated as diyangonins A-C (1-3), along with two known analogs were isolated from the roots of Piper methysticum. Their structures were elucidated by means of extensive analysis of their 1D, 2D NMR, and mass spectroscopic data. All these dimers possess a skeleton featuring a cyclobutane ring connecting two kavalactone units in head-to-tail or head-to-head mode. Compounds 1-5 were evaluated for their cytotoxic activities against human tumor cell lines.

Two new ent-kaurane diterpenes from the stems of Eurya chinensis.

Two new ent-kaurane diterpenes (1-2), together with five known analogs, were isolated from the stems of Eurya chinensis. The structures of new compounds were established by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. Compound 3 exhibited noticeable anti-inflammatory activity as denoted by inhibiting LPS-induced nitric oxide (NO) production in RAW264.7 cells with an IC50 value of 7.82 µM. Compound 4 showed potent cytotoxic activity against human cancer cell lines NCI-H46, HepG2 and SW480 with IC50 values ranging from 7.45 to 8.54 µM.

[Novel type of unperturbed sleep monitoring scheme under pillow based on hidden Markov model].

Sleep status is an important indicator to evaluate the health status of human beings. In this paper, we proposed a novel type of unperturbed sleep monitoring system under pillow to identify the pattern change of heart rate variability (HRV) through obtained RR interval signal, and to calculate the corresponding sleep stages combined with hidden Markov model (HMM) under the no-perception condition. In order to solve the existing problems of sleep staging based on HMM, ensemble empirical mode decomposition (EEMD) was proposed to eliminate the error caused by the individual differences in HRV and then to calculate the corresponding sleep stages. Ten normal subjects of different age and gender without sleep disorders were selected from Guangzhou Institute of Respirator Diseases for heart rate monitoring. Comparing sleep stage results based on HMM to that of polysomnography (PSG), the experimental results validate that the proposed noninvasive monitoring system can capture the sleep stages S1-S4 with an accuracy more than 60%, and performs superior to that of the existing sleep staging scheme based on HMM.

Formation, Aggregation, and Deposition Dynamics of NOM-Iron Colloids at Anoxic-Oxic Interfaces.

The important role of natural organic matter (NOM)-Fe colloids in influencing contaminant transport, and this role can be influenced by the formation, aggregation, and particle deposition dynamics of NOM-Fe colloids. In this work, NOM-Fe colloids at different C/Fe ratios were prepared by mixing different concentrations of humic acid (HA) with 10 mg/L Fe(II) under anoxic conditions. The colloids were characterized by an array of techniques and their aggregation and deposition behaviors were examined under both anoxic and oxic conditions. The colloids are composed of HA-Fe(II) at anoxic conditions, while they are made up of HA-Fe(III) at oxic conditions until the C/Fe molar ratio exceeds 1.6. For C/Fe molar ratios above 1.6, the aggregation and deposition kinetics of HA-Fe(II) colloids under anoxic conditions are slower than those of HA-Fe(III) colloids under oxic conditions. Further, the aggregation of HA-Fe colloids under both anoxic and oxic conditions decreases with increasing C/Fe molar ratio from 1.6 to 23.3. This study highlights the importance of the redox transformation of Fe(II) to Fe(III) and the C/Fe ratio for the formation and stability of NOM-Fe colloids that occur in subsurface environments with anoxic-oxic interfaces.

Shape and size controlled synthesis of uniform iron oxide nanocrystals through new non-hydrolytic routes.

New, non-hydrolytic routes to synthesize highly crystalline iron oxide nanocrystals (8-40 nm, magnetite) are described in this report whereby particle size and morphology were precisely controlled through reactant (precursor, e.g. (FeO(OH)) ratios, co-surfactant and organic additive, and/or reaction time. Particle size, with high monodispersivity (<10%), is demonstrated to be a function of precursor concentrations and through the addition of different cosurfactants and/or additives, cubic, octahedral, potato-like, and flower-like iron oxide nanocrystals can be reproducibly synthesized through simple one-pot thermal decomposition methods. High resolution transmission electron microscope, x-ray diffraction, and superconducting quantum interference device were used to characterize the size, structure and magnetic properties of the resulting nanocrystals. For aqueous applications, materials synthesized/purified in organic solvents are broadly water dispersible through a variety of phase (aqueous) transfer method(s).

Ground State Reactions of nC60 with Free Chlorine in Water.

Facile, photoenhanced transformations of water-stable C60 aggregates (nC60) to oxidized, soluble fullerene derivatives, have been described as key processes in understanding the ultimate environmental fate of fullerene based materials. In contrast, fewer studies have evaluated the aqueous reactivity of nC60 during ground-state conditions (i.e., dark conditions). Herein, this study identifies and characterizes the physicochemical transformations of C60 (as nC60 suspensions) in the presence of free chlorine, a globally used chemical oxidant, in the absence of light under environmentally relevant conditions. Results show that nC60 undergoes significant oxidation in the presence of free chlorine and the oxidation reaction rates increase with free chlorine concentration while being inversely related to solution pH. Product characterization by FTIR, XPS, Raman Spectroscopy, TEM, XRD, TOC, collectively demonstrates that oxidized C60 derivatives are readily formed in the presence of free chlorine with extensive covalent oxygen and even chlorine additions, and behave as soft (or loose) clusters in solution. Aggregation kinetics, as a function of pH and ionic strength/type, show a significant increase in product stabilities for all cases evaluated, even at pH values approaching 1. As expected with increased (surface) oxidation, classic Kow partitioning studies indicate that product clusters are relatively more hydrophilic than parent (reactant) nC60. Taken together, this work highlights the importance of understanding nanomaterial reactivity and the identification of corresponding stable daughter products, which are likely to differ significantly from parent material properties and behaviors.

Aqueous Aggregation Behavior of Engineered Superparamagnetic Iron Oxide Nanoparticles: Effects of Oxidative Surface Aging.

For successful aqueous-based applications, it is necessary to fundamentally understand and control nanoparticle dispersivity and stability over a range of dynamic conditions, including variable ionic strengths/types, redox chemistries, and surface ligand reactivity/degradation states (i.e., surface aging). Here, we quantitatively describe the behavior of artificially aged, oleic acid (OA) bilayer coated iron oxide nanoparticles (IONPs) under different scenarios. Hydrogen peroxide (H2O2), used here as a model oxidant under both dark and light ultraviolet (UVA) conditions, was employed to "age" materials, to varying degrees, without increasing ionic strength. Short-term stability experiments indicate that OA-IONPs, while stable in the dark, are effectively destabilized when exposed to UVA/H2O2/•OH based oxidation processes. Compared to bicarbonate, phosphate (1.0 mM) has a net stabilizing effect on OA-IONPs under oxidative conditions, which can be attributed to (surface-based) functional adsorption. Corresponding aggregation kinetics in the presence of monovalent (Na+) and divalent cations (Ca2+) show that attachment efficiencies (α) are strongly dependent on the cation concentrations/types and degree of surface aging. Taken together, our findings directly highlight the need to understand the critical role of particle surface transformation(s), via oxidative aging, among other routes, with regard to the ultimate stability and environmental fate of surface functionalized engineered nanoparticles.

Engineered crumpled graphene oxide nanocomposite membrane assemblies for advanced water treatment processes.

In this work, we describe multifunctional, crumpled graphene oxide (CGO) porous nanocomposites that are assembled as advanced, reactive water treatment membranes. Crumpled 3D graphene oxide based materials fundamentally differ from 2D flat graphene oxide analogues in that they are highly aggregation and compression-resistant (i.e., π-π stacking resistant) and allow for the incorporation (wrapping) of other, multifunctional particles inside the 3D, composite structure. Here, assemblies of nanoscale, monomeric CGO with encapsulated (as a quasi core-shell structure) TiO2 (GOTI) and Ag (GOAg) nanoparticles, not only allow high water flux via vertically tortuous nanochannels (achieving water flux of 246 ± 11 L/(m(2)·h·bar) with 5.4 µm thick assembly, 7.4 g/m(2)), outperforming comparable commercial ultrafiltration membranes, but also demonstrate excellent separation efficiencies for model organic and biological foulants. Further, multifunctionality is demonstrated through the in situ photocatalytic degradation of methyl orange (MO), as a model organic, under fast flow conditions (tres < 0.1 s); while superior antimicrobial properties, evaluated with GOAg, are observed for both biofilm (contact) and suspended growth scenarios (>3 log effective removal, Escherichia coli). This is the first demonstration of 3D, crumpled graphene oxide based nanocomposite structures applied specifically as (re)active membrane assemblies and highlights the material's platform potential for a truly tailored approach for next generation water treatment and separation technologies.

Anti-inflammatory Inositol Derivatives from the Whole Plant of Inula cappa.

Twelve new inositol derivatives, classified into myoinositol (1-6) and l-inositol (10-15) types, along with five known analogues were isolated from the whole plant of Inula cappa. The structures of the new compounds were established by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. All the tested compounds showed anti-inflammatory activities against the production of NO in RAW264.7 macrophages stimulated by lipopolysaccharide, with IC50 values ranging from 7 to 23 µM.

Aqueous aggregation and surface deposition processes of engineered superparamagnetic iron oxide nanoparticles for environmental applications.

Engineered, superparamagnetic, iron oxide nanoparticles (IONPs) have significant potential as platform materials for environmental sensing, imaging and remediation due to their unique size, physicochemical and magnetic properties. To this end, controlling the size and surface chemistry of the materials is crucial for such applications in the aqueous phase, and in particular, for porous matrixes with particle-surface interaction considerations. In this study, superparamagnetic, highly monodispersed 8 nm IONPs were synthesized and transferred into water as stable suspensions (remaining monodispersed) by way of an interfacial oleic acid bilayer surface. Once stabilized and characterized, particle-particle and model surface interactions (deposition and release) were quantitatively investigated and described systematically as a function of ionic strength (IS) and type with time-resolved dynamic light scattering (DLS), zeta potential, and real-time quartz crystal microbalance with dissipation monitoring (QCM-D) measurements. The critical coagulation concentration (CCC) for oleic acid bilayer coated iron oxide nanoparticles (OA-IONPs) were determined to be 710 mM for NaCl (matching DLVO predictions) and 10.6 mM for CaCl2, respectively. For all conditions tested, surface deposition kinetics showed stronger, more favorable interactions between OA-IONPs and polystyrene surfaces compared to silica, which is hypothesized to be due to increased particle-surface hydrophobic interactions (when compared to silica surfaces).

Reduction of hydroxylated fullerene (fullerol) in water by zinc: reaction and hemiketal product characterization.

Water-soluble, hydroxylated fullerene (fullerol) materials have recently gained increasing attention as they have been identified as the primary product(s) during the exposure of fullerenes (as water stable, nanoscale aggregated C60) to UV light in water. The physical properties and chemical reactivity of resulting fullerols, however, have not been thoroughly studied. In this paper, we identified and characterized the reductive transformation of fullerol (C60(OH)x(ONa)y) by solid zinc metal (Zn(0)) through a series of batch reaction experiments and product characterization, including (13)C NMR, FTIR, XPS, UV-vis, DLS, and TEM. Results indicated the facile formation of water stable, pH sensitive hemiketal functionality as part of a relatively reduced fullerol product. Further, aqueous physical behavior of the product fullerol, as measured by octanol partitioning and surface deposition rates, was observed to significantly differ from the parent material and is consistent with a relative increase in molecular (product) hydrophobicity.