A Benzothiadiazole-Based Zn(II) Metal-Organic Framework with Visual Turn-On Sensing for Anthrax Biomarker and Theoretical Calculation.

2,6-pyridine dicarboxylic acid (DPA) is an exceptional biomarker of notorious anthrax spores. Therefore, the rapid, sensitive, and selective quantitative detection of DPA is extremely significant and urgent. This paper reports a Zn(II) metal-organic framework with the formula of {[Zn6(NDA)6(DPBT)3] 2H2O·3DMF}n (MOF-1), which consists of 2,6-naphthalenedicarboxylic acid (2,6-NDA), 4,7-di(4-pyridyl)-2,1,3-benzothiadiazole (DPBT), and Zn(II) ions. Structural analysis indicated that MOF-1 is a three-dimensional (3D) network which crystallized in the monoclinic system with the C2/c space group, revealing high pH, solvent, and thermal stability. Luminescence sensing studies demonstrated that MOF-1 had the potential to be a highly selective, sensitive, and recyclable fluorescence sensor for the identification of DPA. Furthermore, fluorescent test paper was made to detect DPA promptly with color changes. The enhancement mechanism was established by the hydrogen-bonding interaction and photoinduced electron transfer transition between MOF-1 and DPA molecules.

Ultrasonic Nebulization-Accelerated Gas-Phase Enrichment Following In Situ Microplasma Desorption for Analysis of Trace Heavy Metals by Optical Emission Spectrometry.

Despite the great potential of microplasma optical emission spectrometry (OES) for on-site analysis, it remains a challenge to achieve the fast, sensitive, batch, and multielement analysis of trace heavy metals in a complex matrix. Herein, a novel ultrasonic nebulization-accelerated gas-phase enrichment (GPE) following in situ microplasma desorption sampling approach is employed for the determination of trace heavy metals by a miniature dielectric barrier discharge (DBD)-OES device. The volatile heavy metal species obtained by hydride generation (HG) can be quickly separated from the complex matrix under the action of ultrasonic nebulization, adsorbed on the surface of the activated carbon electrode tip for GPE, and then in situ desorbed and excited by DBD microplasma to achieve multielement OES analysis. With an array nebulizer plate, a batch of 10 samples can be handled for GPE in 40 s, and DBD-OES analysis is maintained at a rate of 6 s per sample. Under the optimized conditions, the detection limits for simultaneous determinations of Hg, Cd, Cu, and Sn are 0.005, 0.01, 0.03, and 0.04 µg L-1, respectively, and the detection sensitivities are about 164, 157, 132, and 91-fold improved with respect to those of the conventional HG-DBD-OES mode, respectively. The accuracy and practicability are verified by measuring several certified reference materials. This fast GPE plus in situ DBD-OES analysis strategy possesses the features of simple operation, time-savings, and low cost, contributing to volatile species transport, matrix interference elimination, and device miniaturization for field applications.

Oxoammonium Salt-Mediated Regioselective Vicinal Dioxidation of Alkenes: Relying on Transient and Persistent Nitroxides.

A novel, easy-to-handle, and regioselective vicinal dioxidation of alkenes under transition metal and organic peroxide free conditions has been developed. This approach uses N-hydroxyphthalimide and its analogues as the transient nitroxyl-radical precursors and 2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (TEMPO+BF4-) as the oxidant as well as the source of persistent nitroxide. By employing this method, multifarious structurally important dioxidation products were efficiently synthesized from simple alkenes and complex bioactive molecule derivatives.

Quantitative 1H Nuclear Magnetic Resonance Method for Assessing the Purity of Dipotassium Glycyrrhizinate.

A simple, rapid, accurate, and selective quantitative method based on 1H nuclear magnetic resonance (qNMR) was successfully established and developed for assessing the purity of dipotassium glycyrrhizinate (KG). In this study, using potassium hydrogen phthalate and fumaric acid as internal standard (IS), several important experimental parameters, such as relaxation delay and pulse angle, were explored. Reliability, specificity, linearity, limit of quantification, precision, stability, and accuracy were also validated. Calibration results obtained from qNMR were consistent with those obtained from HPLC coupled with ultraviolet detection. The proposed method, independent of the reference standard substance, is a useful, reliable, and practical protocol for the determination of KG and glycyrrhizin analogs.

Pharmacokinetics, bioavailability and tissue distribution studies of rhodojaponin III in mice using QTRAP LC-MS/MS.

Rhodojaponin III is a bioactive diterpenoid isolated from the medicinal plant Rhododendron molle G. Don. Quantitative analysis of rhodojaponin III was challenging and the pharmacokinetics of oral rhodojaponin III remained to be investigated. Here, a rapid and sensitive liquid chromatography tandem mass spectrometric (LC-MS/MS) method was developed and validated. The calibration curve was linear over the concentration range of 1-200 ng/mL (r = 0.992). The method was further validated following internationally approved guidelines and all the issues including intra- and inter-day precision, accuracy, carryover, extraction recovery, matrix effects and stability met the recommended limits. The method was then applied to study the pharmacokinetics of rhodojaponin III in mice after intravenous (0.06 mg/kg) or oral (0.24 mg/kg) administration. The results showed that rhodojaponin III had fast oral absorption (time to peak concentration, 0.08 h) and good oral bioavailability (73.6%). In addition, rhodojaponin III was quickly eliminated after it was intravenously or orally administered, with half-life values of 0.19 and 0.76 h, respectively. After oral administration, it was widely distributed in tissues including kidney, lung, heart, spleen and thymus, but had extremely low concentrations in liver and brain. The data presented in this study is beneficial for the further study of rhodojaponin III.

Vignetting correction for a single star-sky observation image.

We propose a method for robustly determining the vignetting function given only a single star-sky image taken by a large-aperture optical system. The actual large-aperture optical system is complex and difficult to model. Thus, the proposed method is designed to determine vignetting distortion of star-sky images without knowing the parameters or model of the optical system. This method is a model-free method by applying a polynomial regular term to the expectation-maximization algorithm to correct vignetting distortion. Unlike prior approaches to single-image vignetting correction, our proposed method, which does not rely on the optical model, gives more accurate results. The effectiveness of this technique was verified using real star-sky images captured with a large-aperture optical system (2-m telescope).

Cyanogenetic glycosides and simple glycosides from the linseed meal.

Three new cyanogenetic triglycosides linustatins A-C (1-3), and two new simple glycosides linustatins D and E (4 and 5) were isolated from the 70% ethanol extract of flaxseed meal (Linum usitatissimum L.). Their structures were elucidated on the basis of spectroscopic analysis and chemical evidence. All of the isolates showed moderate activities against aldose reductase and weak activities against α-glucosidase, DPP-IV, and FBPase at the same concentrations as the positive control drugs.

A new stilbene dimer from Vitis amurensis.

One new stilbene dimer named amurensin O (1), together with one known resveratrol trimer melapinol B (2), was isolated from Vitis amurensis, and their structures were identified on the basis of spectral analysis, especially 2D NMR spectral analysis.

A new resveratrol trimer derivative from Gnetum brunonianum.

A new resveratrol trimer derivative, named as gnetubrunol A (1), together with five known stilbene derivatives, shegansu B (2), resveratrol (3), isorhapontigenin (4), gnetifolin E (5), and isorhapontigenin-11-O-ß-d-glucopyranoside (6) were isolated from the lianas of Gnetum brunonianum Griff. Their structures were elucidated on the basis of spectral analysis (UV, IR, MS, (1)H NMR, (13)C NMR, and 2D NMR). The anti-inflammatory activities of 1, 5, and 6 have also been assayed.

Infection during transgastric and transvaginal natural orifice transluminal endoscopic surgery in a live porcine model.

BACKGROUND: The infection risk of natural orifice transluminal endoscopic surgery (NOTES) is of concern. The aim of this study was to assess the safety of NOTES by investigating the intraperitoneal bacterial load during transgastric and transvaginal procedures with antiseptic or controlling perioperative preparation. METHODS: Forty-five female pigs were randomly assigned to five equal groups: the transgastric (TG) control group (group A), the TG middle volume gastric lavage group (group B), the TG high volume lavage group (group C), the transvaginal (TV) control group (group D) and the TV study group (group E). The study groups received gastric or vaginal lavage and abdominal antimicrobial irrigation, while the control groups received neither. All animals were administered intravenous antibiotics, underwent NOTES peritoneoscopy and transumbilical laparoscopic cholecystectomy under NOTES view with sterile instruments. The viscerotomy was closed by laparoscopic suture. The animals were observed until necropsy was performed 14 days postoperatively. Quantitative bacteriologic cultures were taken from the gastric or vaginal aspirate before and after lavage; peritoneal fluid was collected before and after peritoneal irrigation and at necropsy. RESULTS: The surgical procedures were completed for all the pigs and all of them survived. The mean operative time of the TG group and the TV group was (81 ± 27) minutes and (66 ± 12) minutes, respectively. All animals survived for 14 days. At necropsy, significantly more peritoneal infections were noted in group A than in group D (5:9 vs. 0:9; P < 0.05). No gross evidence of intra-peritoneal infection was found in groups B, C, D and E. Bacteriological evidence was seen in all pigs in group A, 7 pigs in group B, 6 pigs in group D, and none in groups C and E. CONCLUSIONS: Without gastric or vaginal lavage and antibiotic peritoneal irrigation, the TG procedure has a higher infection rate than the TV access. After antiseptic preparation, the bacterial load significantly decreased in the TG group, which seems as safe as the sterile TV approach.

Transumbilical single port laparoscopic cholecystectomy with a simple technique: initial experience of 33 cases.

Transumbilical single port laparoscopic cholecystectomy is a novel laparoscopic surgical technique for cholecystectomy utilizing only a transumbilical incision, which eliminates any visible abdominal scars and improves cosmesis. As the true single port laparoscopic technique, we presented an easy and feasible method for transumbilical laparoscopic cholecystectomy. A total of 33 patients were presented for transumbilical single port laparoscopic cholecystectomy. A 1.5 cm incision was made at the umbilicus. We used one sterile glove and designed a simple method for this procedure. All the operations were completed successfully. The operative time of the first case was 189 min, the average time of the following two cases was 90 min, and the mean of the latest ten cases was 50 min. Operative blood loss was <30 ml for all patients. No drainage tube was placed and no postoperative complications such as bleeding or biliary leakage occurred after three to six months of follow-up. All the patients were discharged 24h after the operation. There were no visible scars on the abdominal wall at the second weekend. Transumbilical single port laparoscopic cholecystectomy by our designed methods was technically simple, feasible and safe. Furthermore, development of newer instruments, accumulation of experience and enhancement of operative technique may facilitate this new operative approach.

A new triglucosylated naphthalene glycoside from Aloe vera L.

A new triglucosylated naphthalene derivative, named aloveroside A (1), together with two known anthraquinone dimers and two 6-phenyl-2-pyrone derivatives, was isolated from the Aloe vera ethanolic extracts. The structure of 1 was established as 1-(((4-(1-O-beta-D-glucopyranosyl -(1-->4)-beta-D-xylopyranoside)-hydroxymethyl)-1-hydroxy-8-O-alpha-L-rhamnopyranoside)naphthalene-2-yl)-ethanone by means of spectroscopic evidences and chemical methods. All these compounds were tested for their BACE inhibitory activity but no significant activities were found.

Jacaranone analogs from Senecio scandens.

Bioassay-guided fractionation of the ethanolic extract of Senecio scandens led to the isolation of four new compounds 4, 5, 7, and 8, along with four known jacaranone analogs (1, 2, 3, 6). Their structures were elucidated on the basis of spectral and chemical evidence. Compound 7 was obtained as a tautomeric mixture of alpha/beta-epimer. The cytotoxic activities of these compounds were evaluated. Among these, compounds 5 and 8 showed potent cytotoxicities. The benzoquinone derivative, jacaranone ethyl ester (1), was the major cytotoxic constituent in this plant with IC(50)s at a range of 0.5-1.0 microg/ml against various tumor cell lines. The SAR of these jacaranone analogs (1-8), isolated from S. scandens, was also discussed.

Total synthesis of adicardin.

The first synthesis of adicardin, a compound with anti-chronic renal failure activity isolated from Hydrangea macrophylla, has been described. The structures of the target compound and intermediates have been validated by MS, NMR, and identical with the natural product.

Synthesis and enantiomeric resolution of (+/-)-pinocembrin.

A convenient method for the synthesis and enantiomeric resolution of ( +/- )-pinocembrin has been developed. This route involves the hydrogenation of 5,7-dihydroxyflavone, the derivatization of racemic pinocembrin with chiral amine, and the separation of the diastereoisomers due to their different physical properties.

BACE1 (beta-secretase) inhibitory chromone glycosides from Aloe vera and Aloe nobilis.

Four new chromone glycosides allo-aloeresin D (2) , C-2'-decoumaroyl-aloeresin G (8), 2'-O-coumaroyl-(S)-aloesinol (9), 2'-O-[ P-methoxy-(E)-cinnamoyl]-(S)-aloesinol (10) and nine known chromone glycosides ( 1, 3 - 7, 11 - 13) were isolated from two Aloe spp. plants, A. vera and A. nobilis. Among them, 1 and 8 showed significant inhibitory activity against BACE1 (beta-secretase) with IC (50) values of 39.0 and 20.5 x 10 (-6) M, as well as inhibition of Abeta (1-42) production by 7.4 and 12.3 %, respectively, in B103 neuroblastoma cells at 30 ppm. The preliminary structure-activity relationships of ALOE chromone glucosides were also discussed.

Jacaranone glycosides from Senecio scandens.

Bioassay-guided fractionation of the ethanol extract of Senecio scandens led to the isolation of four new compounds 1-4. These compounds were obtained as tautomeric mixture of alpha/beta epimers, but their structures were confirmed unambiguously by 1D and 2D NMR spectra and LC NMR technology. 1H NMR spectra of pure 1alpha and 1beta were furnished by HPLC NMR technology. Compounds 1-4 exhibited moderate cytotoxicities against five tumor cell lines.