Survival of Alternaria cheiranthi in soil

Summary Experiments were conducted to study the survival of Alternaria cheiranthi in wet and dry soil. As free spores, survival was demonstrated only in air-dry soil. In wet soil, lysis of the germ tubes commenced after the second day. On wallflower seeds, the pathogen was viable until the seeds were decomposed. It was concluded that the fungus showed a low competitive saprophytic ability in the soil     

Phenolic compounds and antioxidants from Eucalyptus camaldulensis as affected by some extraction conditions,a preparative optimization for GC-MS analysis

Abstract

Four organic solvents along with water were applied for the conventional extraction of Eucalyptus camaldulensis (Myrtaceae), phenolic contents and antioxidant activities were investigated through variable protocols and correlation coefficients were considered, the phenolic composition was also characterized by Gas chromatography-mass spectrometry (GC-MS). Using solvents with dissimilar polarities affected the phenolic yields extracted from E. camaldulensis and their related antioxidant activities varied significantly among the four investigated plant organs. The leaf extract of acetone 70% contained the highest amount of phenolic compounds (46.56?mg/g dry weight); while the bud-water boiled extract maintained the maximum value of tannins (45.68?mg/g dry weight). Correlation coefficients indicated that phenolic compounds were mostly accountable for the phosphomolybednum antioxidant potentials (0.520), followed by tannins (0.460). Also, both the reducing power activities and hydrogen peroxide scavenging of E. camaldulensis extracts positively correlated with tannins, but at different significance degrees. However, the GC-MS analysis revealed that most of the detected phenolic constituents were more abundant in the plant seed. So, the existence of some other compounds such as organic acids, along with phenolics, may have increased the antioxidant potentials of leaf and bud. Undeniably, the optimization of extraction conditions could stimulate the antioxidant capabilities of the plant extracts of E. camaldulensis.     

Evaluation of Papanicolaou stain for studying micronuclei in buccal cells under field conditions

OBJECTIVE: To compare Papanicolaou (Pap) and May-Grünwald Giemsa (MGG) stain as 2 techniques for staining for buccal mucosal cells to detect micronuclei (MN) infield studies. STUDY DESIGN: Eighty cytologic smears (2 per individual) were taken from the buccal mucosa of 40 cigarette smokers recruited at a rural village in Egypt. Forty smears were stained with Pap stain and 40 with MGG stain. All were assessed for cellularity and scored for MN. RESULTS: Pap stain was faster and easier to process and transport in the field study than was MGG stain. Regarding MGG smears, bacteria and cell debris masked the MN as compared to Pap smears, in which the fixative destroyed the bacteria and made the cell boundaries clearly demarcated. Using Pap stain, MN were seen easily in transparent cytoplasm. CONCLUSION: Pap stain is the preferred method infield studies for scoring and detecting MN in cells of buccal mucosa.     

Antioxidant activity of extract of Rhus oxyacantha root cortex

In the present study, the root extract of Rhus oxyacantha contained 25.33 mg of catechin equivalent per mg of fresh wt and was found rich in proanthocyanidins compared to vine shoot, grape pips and leaves. The chromatographic analysis of the extract suggested the presence of (+) catechin, (-) epicatechin -3-O-gallate as well as proanthocyanidinic oligomers and polymers. Root cortex inhibited the ascorbic acid oxidation by dioxygen. It also prevented DDT-induced thymocytes death in a dose-dependent manner. The results suggested antioxidant property of root extract of Rhus oxyacantha which could be ascribed to its free radical scavenging nature.     

Helix‐coil energetics for helix formers and breakers reflect context and temperature: Mutants of helically robust,guest‐sensitive homopeptide hosts

The natural amino acids are primarily helix breakers at the low assignment temperatures characteristic of many studies, but recent genomic analyses of thermophilic proteins suggest that at high temperatures, some breakers may become strong helix formers. Moreover, the breaker/former inventory has not been previously characterized at the physiologically relevant temperature of 37°C. The versatility of ¹³C?O NMR chemical shifts as helicity reporters allows construction of two mutant peptide series, tailored to expand the range of temperature assignments for helical propensities and derived from the core hosts ^tL‐Ala₉XxxAla₉‐^tL and ^tL‐AlaNva₄XxxNva₄Ala₉‐^tL, Nva = norvaline. For three limiting guests Xxx, the helix former Nva and the breakers Gly and Pro, we report w_Xxx[T] assignments at seven temperatures from 2 to 80°C, validating our reasoning and paving the way for assignment of a definitive w_Xxx[T] data‐base. © 2008 Wiley Periodicals, Inc. Biopolymers 91: 311–320, 2009. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com     

Synthesis and properties of chitosan hydrogels modified with heterocycles

Preparation and properties of chitosan modified with heterocycles in absence or presence of gluteraldehyde as a cross linker is described. New modified chitosan–heterocyclic hydrogels were prepared from chitosan and heterocyclic compounds such as N,N′-biisomaleimide, N,N′-biisophthalimide, and N,N′-phthalimidomaleimide via a crosslinking reaction. The new hydrogels chemical structure was characterized by spectral analysis (IR), X-ray diffraction, thermal gravimetric analysis (TGA), solubility, and swellability in water and different organic solvents. Evaluation of the efficiency of the new hydrogels to uptake copper and cobalt ions from aqueous systems was carried out and promising results were obtained.     

<Emphasis Type="Italic">In Vitro</Emphasis> and <Emphasis Type="Italic">In Vivo</Emphasis> Evaluation of Proniosomes Containing Celecoxib for Oral Administration

The objectives of this research were to prepare celecoxib proniosomes and evaluate the influence of proniosomal formulation on the oral bioavailability of the drug in human volunteers. A new proniosomal delivery system for a poorly water-soluble drug such as celecoxib was developed and subjected to in vitro and in vivo studies. Proniosomes were prepared by sequential spraying method, which consisted of cholesterol, span 60, and dicetyl phosphate in a molar ratio of 1:1: 0.1, respectively. The average entrapment percent of celecoxib proniosome-derived niosomes was about 95%. The prepared proniosomes showed marked enhancement in the dissolution of celecoxib as compared to pure drug powder. The bioavailability of 200 mg single dose of both celecoxib proniosomal formulation and a conventional marketed celecoxib capsule was studied in human volunteers. The obtained results show that the proniosomal formulation significantly improved the extent of celecoxib absorption than conventional capsule. The mean relative bioavailability of the proniosomal formulation to the conventional capsule was 172.06 ± 0.14%. The mean T _max for celecoxib was prolonged when given as proniosomal capsule. There was no significant difference between the values of K _el and t _1/2 for both celecoxib preparations. In conclusion, the proniosomal oral delivery system of celecoxib with improved bioavailability was established.     

Isolation,characterization, and cDNA sequence of a carotenoid binding protein from the silk gland of Bombyx mori larvae

A carotenoid binding protein (CBP) has been isolated from the silk glands of Bombyx mori larvae. The protein has an apparent molecular mass of 33 kDa and binds carotenoids in a 1:1 molar ratio. Lutein accounts for 90% of the bound carotenoids, whereas alpha-carotene and beta-carotene are minor components. Immunological analysis demonstrated the presence of CBP only in the yellow-colored tissues of the silk gland, midgut, testis, and ovary. Several phenotypes of B. mori mutants linked to carotenoid transport have been utilized to characterize CBP. The Y (yellow hemolymph) gene controls uptake of carotenoids from the midgut lumen into the midgut epithelium, and larvae with the +(Y) gene lack this property. Immunoblotting analysis confirmed the presence of CBP in mutants with the dominant Y gene only. Immunohistochemistry verified the localization of CBP in the villi of the midgut epithelium, indicating that CBP might be involved in absorption of carotenoids. A cDNA clone for CBP encoding a protein of 297 amino acids has been isolated from the B. mori silk gland cDNA library. The deduced amino acid sequence revealed that CBP is a novel member of the steroidogenic acute regulatory (StAR) protein family with its unique structural feature of a StAR-related lipid transfer domain, known to aid in lipid transfer and recognition. Lutein-binding capacity of the recombinant CBP (rCBP) determined by incubating rCBP with lutein followed by immunoprecipitation using anti-CBP IgG conjugated to protein A-Sepharose, demonstrated the formation of a lutein-rCBP complex. Sequence analyses coupled with binding specificity suggest that CBP is a new member of the StAR protein family that binds carotenoids rather than cholesterol.     

Regiospecific Reduction of 4,6-Dinitrobenzimidazoles: Synthesis,Characterization, and Biological Evaluation

The regiospecific reduction of 4,6-dinitrobenzimidazole derivatives leading to the corresponding 4-amino-6-nitrobenzimidazoles was studied. The identification of the formed product structures was accomplished by spectroscopic and X-ray diffraction data. The anticancer and antiparasitic activities of the synthesized compounds were examined, and promising activities against Toxoplasma gondii and Leishmania major parasites were discovered for certain 4,6-dinitrobenzimidazoles in addition to moderate anticancer activities of the 4-amino-6-nitrobenzimidazole derivatives against T. gondii cells. However, the tumor cell experiments revealed a promising sensitivity of p53-negative colon cancer cells to these compounds.