Fused and spiro nitrogen heterocycles of quinuclidine and its C-nucleosides

Quinuclidin-3-one (1) was used as a versatile intermediate for the synthesis of fused and spiro quinuclidine and its C-nucleosides. The reaction of 1 with formalin and secondary amines namely; morpholine, piperidine, and piperazine afforded the corresponding Mannich bases 2-4 in acid medium. Quinuclidino[3,2-b]pyran 5 has been synthesized via a selective cyclocondensation reaction between Mannich base of quinuclidinone hydrochloride 2 and malononitrile. The transformation of 1 with formalin and methylamine in molar ratio (1:20:2) afforded the spiro compound 7. Ring expansion of 2 under Schmidt reaction conditions gave the 1,3-diazabicyclo[3.2.2]nonanone derivative 6. Eventually, the synthesis of C-nucleosides 10, 12-14 were achieved by using aldohexoses and aldopentose catalyzed by zinc chloride, while, the bis-quinuclidine derivative 15 was obtained by using sodium carbonate. Newly synthesized compounds were characterized by IR, 1H NMR, and mass spectral data

RAPID AND VALIDATED HPLC-UV METHOD FOR DETERMINATION OF GEMIFLOXACIN IN HUMAN URINE

Objective: To develop and validate a simple and rapid reversed phase high performance liquid chromatographic (RP-HPLC) method for the determination of Gemifloxacin (GFX) in human urine.Methods: GFX was isolated from urine samples after acidification using methylene chloride. Good chromatographic separation was achieved using C18 Ultrasphere (250 mm × 4.6 mm, 5 µm.) analytical column maintained at 25 °C. The mobile phase consisted of methanol and 0.1 M phosphate buffer pH 3 in the ratio of (48: 52, v/v), respectively. The analysis time was 10 min at a 1.0 ml/min flow rate. The UV detection was carried out at 272 nm.Results: GFX has been eluted at 7.5 min. Linearity was obtained over a concentration range of 20-200 ng/ml (r2>0.999). The extraction recovery of GFX from urine samples was 60%. The proposed method demonstrated excellent intra-and inter-day precision and accuracy within 1.19% and 100.65 %, respectively. The limit of detection (LOD) was found to be 6.3 ng/ml.Conclusion: Simple and accurate RP-HPLC method for determination of GFX in human urine was developed and validated. The method was successfully applied for determination of GFX in human urine samples from healthy volunteers up to 24 hours after oral administration of 320 mg gemi floxacin tablets.Â

VALIDATED SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF MONTELUKAST SODIUM IN PURE AND DOSAGE FORMS USING N-BROMOSUCCINIMIDE AND DYES

Objective: Simple, sensitive, precise, reproducible and validated spectrophotometric methods have been developed for the quantification of montelukast sodium as leukotriene receptor antagonist drug, in pure and dosage forms (tablets). Methods: The methods use N-bromosuccinimide (NBS) as an oxidant and three dyes, amaranth, methylene blue, and indigo carmine, as auxiliary reagents. The three methods are based on oxidation reaction of montelukast sodium with a known excess of N-bromosuccinimide (NBS) in acid medium, followed by determination of unreacted NBS by the reaction with a fixed amount of dyes, amaranth, methylene blue, and indigo carmine followed by the measurement of the absorbance at 520, 664 and 610 nm, respectively. Results: Under the optimum conditions, linear relationships with good correlation coefficients (0.9993-0.9996) were found over the concentration ranges of 0.5-10, 1.0-12 and 0.5-8.0 µg/ml with a limit of detection (LOD) of 0.15, 0.3 and 0.14 µg/ml using amaranth, methylene blue, and indigo carmine methods, respectively. Intra-day and inter-day accuracy and precision of the methods have been evaluated. No interference was observed from the common tablet excipients. Conclusion: The proposed methods were validated in accordance with ICH guidelines and successfully applied to the analysis of montelukast sodium in dosage forms (tablets). The reliability of the methods was further ascertained by performing recovery studies using the standard addition method. Statistical comparison of the results obtained by applying the proposed methods with those of the reported method by applying student’s t-test and F-test revealed good agreement

SENSITIVE SPECTROPHOTOMETRIC ASSAY OF MUSCARINIC RECEPTOR ANTAGONIST TOLTERODINE TARTRATE IN BULK DRUG AND PHARMACEUTICAL FORMULATIONS

Objective: Simple, sensitive, and accurate spectrophotometric methods have been developed for the assay of tolterodine tartrate (TOL) in bulk drugand pharmaceutical formulations.Methods: The proposed methods are based on oxidation reaction of TOL with a known excess of cerium(IV) ammonium sulfate as an oxidizing agentin acid medium followed by determination of unreacted oxidant by adding a fixed amount of dye, e.g., amaranth (AM), rhodamine 6G (Rh6G), andindigo carmine (IC) followed by measuring the absorbance at 520, 530, and 610 nm, respectively. The effect of experimental conditions was studiedand optimized.Results: The Beer's law was obeyed in the concentration ranges of 1.0-10, 1.0-12, and 0.5-9.0 μg/mL using AM, Rh6G, and IC dyes, respectively, witha correlation coefficient ≥0.9995. The calculated molar absorptivity values are 1.868×104, 1.008×104, and 1.623×104 L/mol/cm using AM, Rh6G, andIC dyes, respectively. The limits of detection and quantification were reported. Intraday and interday accuracy and precision of the methods have beenevaluated. No interference was observed from the additives.Conclusion: The proposed methods were successfully applied to the assay of TOL in tablets preparations, and the results were statistically comparedwith those of the reported method by applying Student's t-test and F-test. The reliability of the methods was further ascertained by performingrecovery studies using the standard addition method

GREEN VORTEX-ASSISTED IONIC LIQUID-BASED DISPERSIVE LIQUID-LIQUID MICROEXTRACTION FOR ENRICHMENT AND DETERMINATION OF CADMIUM AND LEAD IN WATER, VEGETABLES AND TOBACCO SAMPLES

Objective: An eco-friendly, simple and sensitive vortex-assisted ionic liquid-based dispersive liquid-liquid microextraction method (VA-IL-DLLµE) has been proposed to enrich and determine trace levels of cadmium (Cd2+ ) and lead (Pb2+ ) ions in water, vegetables and tobacco samples, prior to its FAAS determination. Methods: The proposed method based on utilization of ionic liquid (IL) (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for both ions after the complexation with 4,5-dihydroxy-3-phenylazo-2,7-naphthalenedisulfonic acid, disodium salt (Chromotrope 2R) at pH 6.5. The impact of different analytical parameters on microextraction efficiency was optimized. Results: In the ranges of 1.0–300 and 2.0-400 μg/ml, the calibration graphs were linear. The limits of detection were 0.3 and 0.6 μg/ml for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 100. The relative standard deviation (RSD %)<3.0%, which indicates the proposed method has high precision. Conclusion: The proposed VA-IL-DLLµE method was developed and applied for the estimation of Cd2+ and Pb2+ ion content in various water, vegetables and tobacco samples, and satisfactory results were obtained. The obtained recovery values showed good agreement with the certified values

INVESTIGATION OF SOME CHEMICAL CONSTITUENTS AND ANTIOXIDANT ACTIVITY OF ASPARAGUS SPERNGERI

Objective: Asparagus sprengeri (A S) is an ornamental plant cultivated in EGYPT. This study was designed to investigate some lipid and flavanoid constituents, in addition to the evaluation of antioxidant activity of different extracts of the plant. Methods: Two phospholipid were identified by (HPTLC). The fatty acid methyl ester and unsaponifiable matter were analyzed by GC. Four flavonoids were isolated by CC and purified by PPc. Identification of isolated flavanoidal compounds was carried by spectroscopic analysis Viz, TLC,PC, UV, EL-MS and H-1– NMR. The different extracts were tested for their free radical scavenging activity using DPPH and β-Carotene- linoleic acid bleaching assay. Results: Four flavonoids, were isolated, apigenin, dihydroquercitin, naringenin, apigenin- 7-o- glucoside Nine fatty acids, Myrestic and linoliec acids were the major components. The unsaponifiable matter was found to be a mixture of hydrocarbons from (C13– C28) and cholesterol two classes of phospholipid were identified namely L-α-Phosphatidyl-DL-glycerol and L-α- Phosphatidylethanolamine. The alcoholic extract of the plant has moderate antioxidant activity with EC50 0.114 and 0.110 mg/ml for the DppH and β-carotene methods respectively Conclusion: Asparagus sprengeri can be used as the natural antioxidant. Flavonoids are suggested to be a group of key antioxidants in Asparagus

New Spectrophotometric and Conductometric Methods for Macrolide Antibiotics Determination in Pure and Pharmaceutical Dosage Forms Using Rose Bengal

Two Simple, accurate, precise, and rapid spectrophotometric and conductometric methods were developed for the estimation of erythromycin thiocyanate (I), clarithromycin (II), and azithromycin dihydrate (III) in both pure and pharmaceutical dosage forms. The spectrophotometric procedure depends on the reaction of rose bengal and copper with the cited drugs to form stable ternary complexes which are extractable with methylene chloride, and the absorbances were measured at 558, 557, and 560 nm for (I), (II), and (III), respectively. The conductometric method depends on the formation of an ion-pair complex between the studied drug and rose bengal. For the spectrophotometric method, Beer's law was obeyed. The correlation coefficient () for the studied drugs was found to be 0.9999. The molar absorptivity (), Sandell’s sensitivity, limit of detection (LOD), and limit of quantification (LOQ) were also calculated. The proposed methods were successfully applied for the determination of certain pharmaceutical dosage forms containing the studied drug

Isolation, characterization, and ELISA applications of alkaline phosphatase and acetylcholinesterase from Moniezia expansa

Moniezia expansa worms are a significant source of alkaline phosphatase (ALP) and acetylcholinesterase (AChE) enzymes. The current study presents a simple and reproducible ALP and AChE purification method from Moniezia expansa helminthes by precipitating the proteins with ammonium sulfate and chromatography on the Sephacryl S-300 column. The M. expansa ALP purified at 1070.8 U/mg, displaying 6.0 purification folds and 53.6% yield, while M. expansa AChE is at 5250 U/mg, displaying 2.0 purification folds and 43% yield. The M. expansa ALP isoenzyme displayed its optimum activity at pH 9.6, while the M. expansa AChE isoenzyme displayed its optimum activity at pH 8.0. The affinity of M. expansa ALP for several substrates revealed that p-nitrophenyl phosphate preferentially cleaved with a Km value of 4.4 mM. M. expansa AChE preferentially cleaved acetylthiocholine iodide with a Km value of 0.9 mM. M. expansa ALP is strongly stimulated with Co2+, Mn2+, Ni2+, and Mg2+and reduced with Zn2+, Cu2+, Ca2+, EDTA and DTT. On the other hand, M. expansa AChE is significantly induced with Co2+, Zn2+, and Ni2+and inhibited with Mg2+, Ca2+, EDTA, 1,10-phenanthroline and eserine. The antisera of the purified M. expansa ALP and AChE found effective for determining the two enzymes in different unknown sera from different animal species, including humans, sheep and fish. These results may provide a possible future application of such enzymes in producing ALP and AChE-coated ELISA plates for research purposes

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised