Pepsin as a catalyst of peptide synthesis. Enzyme co-precipitation with emerging peptide products.

Pepsin successfully catalyzed the synthesis of several peptide derivatives from N-protected di- or tripeptides and amino acid or peptide esters or p-nitroanilides in dimethylformamide-water solutions at pH 4.6. An optimal substrates:pepsin ratio depended on the structure of starting peptides, especially their fit to the substrate binding sites of the enzyme. For hexapeptide Z-Ala-Ala-Phe-Leu-Ala-Ala-OCH3 formation, an equilibrium yield was attained at 1:3.10(5) enzyme-substrates ratio that indicated high efficiency of pepsin in synthesis reactions. In the course of the equilibrium peptide synthesis, pepsin gradually disappeared from the liquid phase due to its entrapment within a gel, formed by the hexapeptide product, while retaining its activity. The inclusion into the precipitate was not specific for pepsin, so far as inert proteins, lysozyme, ribonuclease A and carbonic anhydrase, when added to the reaction mixture, became also co-precipitated with the hexapeptide formed. It appears that co-precipitation of pepsin, an important factor limiting the enzyme efficiency, might be operative as well for other proteinases used to catalyze peptide synthesis.     

A carotane derivative and a eudesmanolide from Inula crithmoides*

The aerial parts of Inula crithmoides afforded a new carotane derivative and a eudesmanolide, inucrithmolide. The most probable structures were elucidated by the spectroscopic data and by some chemical transformations.     

Effect of high pressure ammoniation procedure on the detoxification of aflatoxins

Ammoniation represents the best technique to detoxify aflatoxin-contaminated grain and it is considered as economically practicable for commercial applications. In the present studyAspergillus parasiticus was used to contaminate yellow corn to produce the final concentration reached 4000 μg/kg corn total aflatoxin. Two procedures of ammoniation (in aqueous ammonia concentrations, 0.25, 0.5, 1, 1.5 and 2% ) were adopted for aflatoxin destruction. The first procedure was under atmospheric pressure at ambient temperature (AP/AT) for 24 hrs, and the second procedure was under high pressure (2 bar) at high temperature (121°C) (HP/HT ) for 15 min. Aflatoxin concentrations were determined by HPLC using fluorescence detection. The effect of HP/HT procedure was compared with the ammoniation procedure under AP/AT. The detoxification pattern of the two ammoniation procedures as well as the detoxification pattern of the different types of aflatoxins under the two procedures was studied.     

A survey of the pathogenic fungi of mycotic infection of the scalp in U.A.R.

Summary 121 cases diagnosed clinically as tinea capitis were examined microscopically and culturally. In 80 cases the causative organism could be cultured.T. violaceum was the causative organism of the majority of the cases as it caused 47.5 % of the cases,T. schoenleinii 31.3 %,M. canis caused 26.1 %,T. tonsurans 1.3 %, whileM. audouinii caused none. In most of the cases ofT. violaceum infection, scaling and mild inflammation were the common clinical manifestation. The black dot or the bald patch appearance was rarely seen. Favus did not necessarily show the characteristic scutulae; in many cases ofT. schoenleinii infection, only few scales and mild inflammation were present.     

Lycopene is superior to moringa in improving fertility markers in diet-induced obesity male rats

Obesity is a condition of chronic tissue inflammation and oxidative stress that poses as a risk factor for male infertility. Moringa oleifera oil extract is known to have cholesterol-lowering properties and a potential to treat obesity, while lycopene is a potent antioxidant. We hypothesize that Moringa or lycopene may improve male fertility markers in an animal model of diet-induced obesity. Male Albino rats (n = 60) were randomized to receive regular chow (RC) or high-fat diet (HFD) for 12 weeks (n = 30 each). Animals in each arm were further randomized to receive gavage treatment with corn oil (vehicle), lycopene (10 mg/kg), or Moringa (400 mg/kg) for four weeks starting on week 9 (n = 10 each). Animals were sacrificed at 12 weeks, and blood was collected to assess lipid profile, serum testosterone, and gonadotropin levels. The testes and epididymides were removed for sperm analysis, oxidative stress and inflammatory markers, and histopathological assessment. In comparison to their RC littermates, animals on HFD showed an increase in body weights, serum lipids, testosterone and gonadotrophin levels, testicular oxidative stress and inflammatory markers, as well as sperm abnormalities and disrupted testicular histology. Moringa or lycopene reduced body weight, improved oxidative stress, and male fertility markers in HFD-fed animals with lycopene exhibiting better anti-antioxidant and anti-lipidemic effects. Lycopene is superior to Moringa in improving male fertility parameters, possibly by attenuating oxidative stress.     

Effects of steroid anaesthesia on some liver function tests in goats

The effect of Saffan, a steroid anaesthetic, on the liver function of goats has been studied. Forty healthy animals were divided into 4 equal groups. The first 2 groups were given 2 and 4 mg Saffan/kg b. wt respectively. A mixture of Saffan (1 mg) and Xylazine (0.1 mg)/kg b. wt was given to the third group and Xylazine alone to the fourth group (0.1 mg/kg b. wt). Serum samples from all groups were analysed for glucose, total protein, total and direct bilirubin and the level of activity of transaminases. Administration of Saffan evoked more hyperglycemia than a mixture with Xylazine, or Xylazine alone. The hyperglycemic effect of both doses of Saffan (2 and 4 mg) was equivocal beyond 2 h. The effect then differed and glucose was increased 4-fold by 2 mg and 3-fold by 4 mg Saffan. Serum total protein, conjugated and total bilirubin, and GPT and GOT were not changed in the four experimental groups. This was good evidence of a normally functioning liver during the course of steroid anaesthesia administration in goats.