M. K. A. Ibrahim

Effect of air injection under subsurface drip irrigation on yield and water use efficiency of corn in a sandy clay loam soil.

Subsurface drip irrigation (SDI) can substantially reduce the amount of irrigation water needed for corn production. However, corn yields need to be improved to offset the initial cost of drip installation. Air-injection is at least potentially applicable to the (SDI) system. However, the vertical stream of emitted air moving above the emitter outlet directly toward the surface creates a chimney effect, which should be avoided, and to ensure that there are adequate oxygen for root respiration. A field study was conducted in 2010 and 2011, to evaluate the effect of air-injection into the irrigation stream in SDI on the performance of corn. Experimental treatments were drip irrigation (DI), SDI, and SDI with air injection. The leaf area per plant with air injected was 1.477 and 1.0045 times greater in the aerated treatment than in DI and SDI, respectively. Grain filling was faster, and terminated earlier under air-injected drip system, than in DI. Root distribution, stem diameter, plant height and number of grains per plant were noticed to be higher under air injection than DI and SDI. Air injection had the highest water use efficiency (WUE) and irrigation water use efficiency (IWUE) in both growing seasons; with values of 1.442 and 1.096 in 2010 and 1.463 and 1.112 in 2011 for WUE and IWUE respectively. In comparison with DI and SDI, the air injection treatment achieved a significantly higher productivity through the two seasons. Yield increases due to air injection were 37.78% and 12.27% greater in 2010 and 38.46% and 12.5% in 2011 compared to the DI and SDI treatments, respectively. Data from this study indicate that corn yield can be improved under SDI if the drip water is aerated.

Studies with polyfunctionally substituted heteroaromatics: synthesis of several new thiazoles, pyrazolo[5,1-c]triazines and of polyfunctionally substituted pyridines and pyrimidines.

Abstract Several thiazolin-4-one(3), 1,2,4-triazinethione (13), pyrazolo[1,5-c]-1,2,4-triazine (16) and pyridine (23) derivatives could be obtained via the reaction of iminoether (1) derivative with thioglycolic acid, aryldiazonium chloride, 3-arylpyrazol-5-yl diazonium chloride and alkylidenemalononitrile derivatives, respectively. The reaction mechanism for each one was discussed. All structure were suggested on the basis of elemental analyses and spectral data.

Stability of catechins in green tea nutraceutical products: Application of solid phase extraction–thin layer chromatography densitometry

Epigallocatechin gallate (EGCG) is a powerful antioxidant and commonly used nutraceutical. Accelerated stability of EGCG in tablet formulations was investigated. LLE and SPE were employed for sample clean-up and enrichment of EGCG over caffeine. Samples were analysed after spiking with fixed concentration of gallic acid (GA), in order to verify reproducibility of analysis. A TLC-densitometric assay was developed and validated for determination of % loss EGCG. EGCG, GA and caffeine were resolved with Rf values 0.54, 0.69 and 0.80, respectively. LC-MS/MS was used to verify identity and purity of the EGCG band. Determination was carried out over a concentration range of 0.50-5.00μg/band and 0.20-2.40μg/band for GA and caffeine, respectively. Results showed significant reduction in EGCG content after one, three and six months: 24.00%, 28.00% and 52.00% respectively. Results continue to demonstrate that stability of nutraceutical products should be investigated in-depth using industry-oriented protocols before granting marketing authorisation.

UTILITY OF HYDRAZIDOYL HALIDES IN HETEROCYCLES: A NEW ROUTE FOR THE SYNTHESIS OF ALKYLMERCAPTOHETEROCYCLIC COMPOUNDS

Abstract The reaction of hydrazidoyl chloride (I) with ethyl mercaptan afforded the thioether derivative II. Compound II was converted to the pyridazine derivative III by fusion with ethyl cyanoacetate. Compound III was converted to the corresponding dioxide derivative IV. Compound III was utilized to synthesize a variety of heterocyclic compounds such as phthalazine and thieno[2,3-d] pyridazine derivatives, VIIIa-e and XI, respectively. Compound XI underwent chemical transformations to afford several new heterocyclic compounds. All structures were established on the basis of elemental analyses and spectral data.

Correlation of In Vivo and In Vitro Assay Results for Assessment of Free Radical Scavenging Activity of Green Tea Nutraceuticals

Green tea (GT)-derived catechins; epigallocatechin gallate (EGCG) in particular are commonly used nutraceuticals for their free-radical scavenging activity (FRSA). The influence of photodegradation on the protective power of GT nutracenticals against oxidative stress was thoroughly explored. Photodegradation of GT extracts was carried out and monitored using orthogonal stability-indicating testing protocol; in vitro and in vivo assays. Total polyphenol content (TPC) and FRSA were determined spectrophotometrically while EGCG was selectively monitored using SPE-HPLC. In vivo assessment of photodegraded samples was investigated via measuring a number of biomarkers for hepatic oxidative stress and apoptosis (caspase-3, inducible nitric oxide synthase, nitric oxide, mitogen-activated protein kinase, glutathione, thiobarbituric acid reactive substances, nuclear factor kappa beta, and nuclear factor erythroid 2-related factor) as well as liver damage (alanine transaminase and aspartate transaminase) in serum of rats previously subjected to oxidative stress. Results showed complete degradation of EGCG in photodegraded green tea samples with no correlation with either TPC or FRSA. On the other hand, in vivo assay results revealed not only loss of activity but formation of harmful pro-oxidants. Photostability was found crucial for the protective effect of GT extract against lead acetate insult. Results confirmed that careful design of quality control protocols requires correlation of chemical assays to bioassays to verify efficacy, stability, and most importantly safety of nutraceuticals.

Studies with Polyfunctionally Substituted Heterocycles: Synthesis of New Pyridines, Naphtho[1,2-b]pyrans, Pyrazolo[3,4-b]pyridines and Pyrazolo[l,5-a]pyrimidines

A variety of new polyfunctionally substituted pyridines, naphthopyrans and pyrazolopyrimidines were prepared via reacting ylidenemalononitriles with thiophenol, thionaphthol, naphthols and or aminopyrazoles.

Photodegradation and photostability-indication of mequitazine

The photochemical behavior is investigated for mequitazine (MQ) illustrating possible mechanisms and photodegradation products formed. Accelerated photolysis is done for MQ under justified stress conditions by subjecting aqueous drug solutions to radiation for specified period of time. Synthesis of the main photodegradants, the sulfoxide, is achieved. Selective quantification of MQ, singly in bulk form, pharmaceutical formulations and/or in the presence of its photodegradants is demonstrated. The indication of stability has been undertaken under conditions likely to be expected at normal storage conditions using a simple colorimetric method based on oxidation of the intact phenothiazine drug by potassium iodate in acid medium to form a red colored product adequate for quantitative estimation of the studied drug.

Activated Nitriles in Heterocyclic Syntheses, I Novel Synthesis of Pyrrolones and 1,2,4-Triazol-3-oyl nitriles

Abstract Heterocyclic Synthesis, Pyrrolones The behaviour of 4-benzylidene-2-oxazolin-5-one (2) and of 4-phenylazo-2-oxazolin-5-one (3) toward a variety of active methylene reagents is reported. Cleavage of the oxazolin-5-one ring was observed in most cases. A variety of new, otherwise, difficult accessible, azolyl derivatives could be prepared.

Comparative Study Between Conventional Fasting Versus Overnight Infusion of Lipid or Carbohydrate on Insulin and Free Fatty Acids in Obese Patients Undergoing Elective On-pump Coronary Artery Bypass Grafting. A Prospective Randomized Trial

OBJECTIVES Postoperative insulin resistance represents a major component of postoperative metabolic disorder. The authors compared the effects of preoperative infusion of lipid emulsion or carbohydrate to conventional preoperative fasting on postoperative insulin and free fatty acid (FFA) levels. DESIGN A prospective randomized double-blinded study. SETTINGS Tertiary university hospital. PARTICIPANTS Sixty-three patients undergoing coronary artery bypass grafting. INTERVENTION Participants were randomized into 3 equal groups. Group G received 500 mL of glucose 10% (50 g glucose). Group L received 100 mL of 2% lipid emulsion (soybean 30%, medium chain triglycerides (TG) 30%, olive oil 25%, fish oil 15%, and 20 mg vitamin E). Group C fasted overnight except for clear fluids allowed until 4 hours preoperatively. Serum insulin at the start of infusion (T1), 1-hour preinduction (T2), on admission to the intensive care unit (T3), after 24 hours of admission (T4), and after 48 hours of admission (T5), and FFA at T1 and T2 were measured. Serum very-low-density lipoprotein (VLDL), serum TG, and blood sugar were all measured (T1-T4). Bypass time, ischemic time, need for inotropic support, and length of intensive care unit stay also were measured. MEASUREMENTS AND MAIN RESULTS At the end of infusion FFAs were significantly lower in the L group (1.1 ± 0.76 mg/dL) compared with G (1.64 ± 0.85 mg/dL) and C groups (1.48 ± 0.76 mg/dL). Insulin levels were significantly lower in the L group compared with levels in the G and C groups at T2, T3, and T4. Also, TG, VLDL, and random blood sugar levels decreased significantly at T2, T3, and T4 in the L group compared with the other 2 groups and compared with baseline value within the same group. CONCLUSION Preoperative lipid infusion lowered postoperative FFA, insulin, TG, VLDL, and random blood sugar in obese patients undergoing coronary artery bypass grafting surgeries.

Benzoin in heterocyclic synthesis: Synthesis and reactions of 2,3-Diphenyl-4-cyanopyrrole-5-thione

Abstract2,3-Diphenyl-4-cyano-pyrrole-5-thione (4) was prepared either by the reaction of benzoin (1) and cyanothioacetamide (3) followed by cyclization using AcOH/sodium acetate or by refluxing a mixture of benzoin (1) and cyanothioacetamide in pyridine to afford directly4. Several new pyrrole and pyrazole derivatives were synthesised using4 as synthon. The structure of the newly synthesised derivatives were based on celemental and spectral data studies. Methylation of the SH group in4 afforded5. Reaction of4 with ethyl bromo acetate afforded (6). Treatment of (5) and (6) with hydrazine hydrate afforded the same pyrazole derivative (10) through the intermediate (9). Treatment of6 with aniline and phenylhydrazine afforded the pyrrole derivatives8a,b respectively. Treatment of6 while dil HCl gave 2,3-diphenyl-4-cyano-pyrrole-5-one (7). Treatment of6 with NH3/EtOH afforded the amidic derivatives (11) with treatment of6 with NH3/heat then acidification it gave the carboxylic derivatives (12).