Synthesis and reaction of pyrido[2,3-d] pyrimidine with related thiazolo and enaminonitrile derivatives

In a one-pot synthesis pyrido[2,3-d] pyrimidine-2-thione derivatives [3a-c] were prepared via the reaction of a mixture of 6-aminothiouracil [1], cyclooctanone and a proper aldehyde in dimethylformamide. Compound 3 reacted with a mixture of chloroacetic acid and aromatic aldehyde in acetic acid and acetic anhydride to give 6-aryl-thiazolo [4,5-a] cyclooctenopyrido [2,3-d] pyrimidine -3,5-diones [4a-c]. Compound 3b underwent cyclization on boiling with 3-chloro-2,4-pentandione in acetic anhydride/pyridine solution to give 5. On the other hand, compound 3b reacted with bromo-malononitrile to give enaminonitrile [6] Compound 6 reacted also with aliphatic acids to give 14-[chlorophenyl]-2-[unsub./methyl] pyrimido[4',5':4,5] thia-zolo[3,2-a] cyclooctenopyrido [23-d] pyrimidine- 4,15- dione [8a,b]

Thioxopyridinecarbonitrile as a precursor for thieno- and pyrazolopyridines

Pyridinethione 1 reacted with alkyl halides or with aliphatic alpha halocarbonyl to yield the corresponding alkylthio- derivatives 4[a-e], which underwent ring closure to form derivatives 5[a-e] Pyridinethione 1 reacted with bromomalononitrile, to give the thieno [2,3-b] pyridine-2,2-dicarbonitrile derivatives 6. Compound 1 reacted with bromomalononitrile to yield structure 7, which was elucidated by the reaction of bromomalononitrile with 8 to furnish compound 9. Treatment of each of 4[b] and 11[13] with hydrazine hydrate, respectively, afforded 3-amino-4-[4-chlorophenyl]-6-phenyl-1 H-pyrazolo [3,4-b] pyridine-5-carboxanilide [12] and ethyl 3-amino-4-[4-chlorophenyl]-6-methyl-lH-pyrazolo[3,4-b] pyridine-5-carboxylate [13], respesctively

Quality evaluation of yoghurt collected from the local market in some governorates of Egypt

The present study was carried out to evaluate quality of yoghurt collected from the local market in Cairo, Giza, Gharbia and Minufiya governorates and to compare it with the manufactured yoghurt using Bifidobacteria bifidum [B. bifidurn] added to normal starter. Physicochemical, microbiological and organoleptic properties of all yoghurt samples were determined during 12 days storage period in a refrigerator. The results showed that yoghurt collected from Cairo and Giza markets contained less content of total solids and fat than that collected from Gharbia and Minufiya markets as compared to the manufactured yoghurt using B. bifidum. Microbiological examination revealed that the total viable bacterial count was less in yoghurt collected from Cairo and Giza markets than that collected from Gharbia and Minufiya markets. The coliform, mold and yeast count was nil or ignorable in all yoghurt samples till 6 days of storage, then these microorganisms were detected on the 9[th] and the 12[th] day of storage period. Organoleptic properties showed that the yoghurt collected from Cairo and Giza markets has higher sensory scores and more acceptable than that collected from Gharbia and Minufiya markets. The manufactured yoghurt using B. bifidum has the best quality and high degree of acceptability by consumers

Evaluation of pumpkin jam prepared with different sweeteners

Pumpkin jam was prepared by replacing sucrose with different sweeteners e.g. 100% high fructose corn syrup [HFCS], aspartame, stevia, 50% sucrose with 50% HFCS with 50% stevia and 50% HFCS with 50% stevia. The prepared jam were stored for 6 months and 25°C, during which they were analyzed for chemical, physical and sensory properties. It has been shown that replacing sucrose with the sweeteners affected the physical and chemical properties of the prepared jam. Meanwhile sucrose with other sweeteners replacement during the preparation of pumpkin jam resulted in a decrement in the total soluble solids [TSS]. The total and reducing sugars in jam prepared with 100% stevia or aspartame recorded the lowest values at zero time. During storage, the total acidity slightly changed in all jam. Total caloric values decreased in different pumpkin jam compared to the control jam [100% sucrose]. However, the reduction in caloric value ranged between 73.25 to 36.35%. Moreover, the prepared jam is considered as a good source of beta -carotene with relatively higher Retinol equivalent [R.E]. Sensory evaluation indicated that the prepared jam were significantly changed by the substitution of sucrose with 100% stevia or aspartame. No significant difference was found in the jam prepared by 100% sucrose, 100% HFCS, 50% sucrose with 50% HFCS, 50% sucrose with 50% stevia and 50% HFCS with 50% stevia. Storage period caused a slight effect on sensory parameters for most jam except for the jam prepared with 100% stevia or aspartame

Influence of mixed bee-pollen on rat a health

Mixed bee pollens were collected from fields cultivated by sunflower, palm and oxeye daisy plants at Fayoum governorate. The gross chemical composition and the profiles of amino acids and minerals of bee collected mixed pollens were determined. Nutritional experiments were preformed on adult and elderly female rats fed on basal diet and orally supplemented by mixed bee pollen at 2% and 4% levels. Blood samples of adults and elderly female rats were collected at start and after 10, 20, and 30 days of the experiments. Serum total lipids, high-density lipoproteins, triglycerides, total lipids, progesterone and calcium levels were estimated for both adults and elderly female rats. At the end of the experiment, the adult and elderly female rats were allowed to mate and the numbers of fetuses in both cases were counted. The basal diet supplemented with mixed bee pollen induced a lowering lipid effect, increased HDL-cholesterol, progesterone, calcium levels and fertility of elderly female rats

Headspace analysis of buttermilk

The volatile flavor compounds of commercially cultured buttermilk were analyzed by head space gas chromatography to study the flavor changes occurring during 2 weeks of storage at 8 degree. Separation of acetaldehyde, acetic acid, diacetyl, acetoin and 2,3-butylene glycol was achieved by using a 100/150 mesh Porapak-Q column in a gas chromatograph equipped with a flame ionization detector. The column was programmed to operate at the rate of 10 degree per minute from 100 to 200 degree with a nitrogen carrier gas flow of 45 ml per minute. Tentative identification of the resultant peaks was made by comparing the retention of the peaks on the chromatograms of the samples and known mixed standards. Large variations in concentrations of volatile compounds were apparent. Moreover, the ratio of diacetyl to acetaldehyde in the samples showed considerable variation. An increase in acetaldehyde and acetic acid with a decrease in diacetyl, acetoin and 2, 3-butylene glycol occurred during storage. The increase in acetaldehyde and acetic acid and the decrease in diacetyl, acetoin and 2, 3-butylene glycol were closely related to the rapid decrease in product acceptability during storage

Production of milk hydrolysate for fortification of beverages

A modification of the process of Helbig et al. [1980] for preparation of a non-bitter desalted milk hydrolysate was presented. Skim milk was hydrolyzed with alcalase at 45 degree in 4 hours. The resin in OH form was added to milk batches with caution to simultaneously raise the pH to 8.5 for optimum proteolysis and exchange the anions in milk which contributed to saltiness. These modifications resulted in a shorter hydrolysis time and a more economical resin regeneration. The dried milk hydrolysate was added to soft drinks at solids concentrations up to 10% [3% protein] without adverse effects on their taste, color and clarity

role of psychotropic bacteria in raw milk on stability of milk proteins to UHT treatment

The effects of psychrotrophs growth on proteins of raw skim milk and the response of milk proteins to UHT-treatment were studied. 4 psychrotrophs isolated from raw milk attacked raw skim milk proteins. k and B-caseins were most susceptible although some of the isolates also attacked the whey proteins. Growth of psychrotrophs in raw skim milk predisposed the proteins to deleterious effects of UHT-treatment. Ultrahigh temperature had little effect on raw skim milk caseins while, decreased alpha-lactalbumin and B-lactoglobulin by 22% and 36%, respectively. Milk that had undergone proteolysis exhibited decreased detectable k-, B-, and alpha S-caseins but increased loss of B- lactoglobulin as a result of UHT-treatment. Milk suffering extensive k-casein degradation coagulated during UHT-treatment. Coagulation during or shortly after heating increased with severity of heat treatment and size of psychrotrophs population

Thermal denaturation of whey proteins: effect of pH and milk sugars

Influence of pH and milk sugars on thermal stability of whey proteins were studied using heat-induced precipitation and differential scanning calorimetry Heating whey at 90°C for 10 min above pH 3.7 to 3.9 produced extensive protein denaturation. When the same heat treatment was applied below pH 3.7 protein precipitation was greatly reduced; however, protein denaturation still occurred in various whey protein fractions. Presence of milk sugars [lactose, glucose, and galactose] appeared to increase the thermal stability of beta-lacto globulin. Heat stability of alpha-lactalbumin was less at pH 3.5 than in the pH 6.5 to 4.5 range; at all pH denaturation temperatures of alpha-lactalbumin [61.6 to 57.6C] were lower than those for beta-lacto globulin or serum albumin