25 research outputs found

    Facies analysis, glauconite distribution and sequence stratigraphy of the middle Eocene Qarara Formation, El-Minya area, Egypt

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    AbstractThe Qarara Formation consists mainly of shale at the base and overlain by limestone at the top. The formation is Middle Eocene (Lutetian) in age. Three sections located at the eastern bank of the Nile River in El-Minya Province have been measured, described, and sampled. These sections from north to south are: Gebel Qarara, El-Sheikh Fadl, and Gebel El-Ahmar.The main microfacies identified in the studied sections are: silty claystone, silty shale, fossiliferous glauconite, glauconitic (green) sand, glauconitic fossiliferous ironstone, glauconitic bioclastic wacke-packstone, glauconitic bioclastic lime-mudstone-wackestone. These microfacies have been deposited in shallow open marine environment.Collectively the studied rocks contain two principal facies: lower argillaceous facies and upper carbonate facies that separated by glauconitic fossiliferous ironstone bed. The lower argillaceous part represents highstand systems tract (HST), whereas the upper carbonate part represents transgressive systems tract (TST). The glauconitic fossiliferous ironstone bed is recognized as a sequence boundary (SB)

    Chemical studies of chromanone-thiadiazole, pyridazine and thiosulfin hybrid

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    3-Chlorochromanon derivatives 4a,b are reacted with hydrazine hydrate to afford 3-hydrazino-2-tetrahydro(pyran or thiopyran)chroman-4-ones 5a,b. Then compound 5a,b is reacted with carbon disulfide and acetylacetone to give 5'-thiolo - 2-tetrahydro(pyrane or thiopyran)- spiro[chroman-3,2'- [1,3,4]-thiadiazole]-4-one 6a,b and 3', 5'-dimethyl- 2-tetrahydro(pyran or thiopyran) spiro [chroman-3,2'- piprazine]-4-one 7a,b, respectively. α-Chlorosulfenyl chlorides 2a,b are treated with thioacetic acid to form α-chloroalkyl disulfides 8a,b, the latter compounds 8a,b were treated with morpholine to furnish a mixture of 1,3,4-oxadithiins 9a,b, 1,3,4,5,6-oxatetrathiocins 10a,b, 1,2,4-trithiolanes 11a,b (cis- and trans-), 1,2,4,5-tetrathiins (cis- and trans-) 12a,b. The formation of the new compounds are confirmed by spectral (IR, 1H NMR, and MS) analysis

    Conserved peptides within the E2 region of Hepatitis C virus induce humoral and cellular responses in goats

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    The reason(s) why human antibodies raised against hepatitis C virus (HCV) E2 epitopes do not offer protection against multiple viral infections may be related to either genetic variations among viral strains particularly within the hypervariable region-1 (HVR-1), low titers of anti E2 antibodies or interference of non neutralizing antibodies with the function of neutralizing antibodies. This study was designed to assess the immunogenic properties of genetically conserved peptides derived from the C-terminal region of HVR-1 as potential therapeutic and/or prophylactic vaccines against HCV infection. Goats immunized with E2-conserved synthetic peptides termed p36 (a.a 430–446), p37(a.a 517–531) and p38 (a.a 412–419) generated high titers of anti-p36, anti-p37 and anti-P38 antibody responses of which only anti- p37 and anti- p38 were neutralizing to HCV particles in sera from patients infected predominantly with genotype 4a. On the other hand anti-p36 exhibited weak viral neutralization capacity on the same samples. Animals super-immunized with single epitopes generated 2 to 4.5 fold higher titers than similar antibodies produced in chronic HCV patients. Also the studied peptides elicited approximately 3 fold increase in cell proliferation of specific antibody-secreting peripheral blood mononuclear cells (PBMC) from immunized goats. These results indicate that, besides E1 derived peptide p35 (a.a 315–323) described previously by this laboratory, E2 conserved peptides p37 and p38 represent essential components of a candidate peptide vaccine against HCV infection

    Derivatization and biological activity studies of 3-chloro-3-chlorosulfenyl spiro tetrahydropyran/tetrahydrothiopyran-4,2'-chroman-4'-one

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    1502-1510The adducts 4a,b-7a,b have been obtained either by reducing α-chloro-β-oxosulfenyl chlorides 2a,b with iodide ion in the presence of dienes namely, 2-methyl-1,3-butadiene (isoperene), 2,3-dimethyl-1,3-butadiene, 1,2,3,4- tetrachlorocyclopentadiene, or 1,3-cyclohexadiene, respectively; or by thermolysis of oxadithiin derivatives 3a,b in the presence of the same aforementioned dienes presumably via the formation of the same intermediate A in both cases of compounds 2a,b and 3a,b. It is observed that α-chloro-β-oxosulfenyl chlorides 2a,b undergo straight forward substitution with potassium cyanide to give 8a,b. Direct oxidation of 2a,b with H2O2/AcOH affords 3,3-dichloropyran-4-ones 9a,b, while conversion of 2a,b to the sulfonamides 10a,b followed by oxidation provides 3-chloropyranones 11a,b. Antioxidant and antimicrobial evaluation of compounds 4a,b-6a,b shows moderate activiy. MIC of the derivative 6b reveals a remarkable inhibition of the pathogenic gram positive bacteria (Staphylococcus aureus ) as well as gram negative E coli

    Derivatization and biological activity studies of 3-chloro-3-chlorosulfenyl spiro tetrahydropyran/tetrahydrothiopyran-4,2'-chroman-4'-one 

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    The adducts 4a,b-7a,b have been obtained either by reducing α-chloro-β-oxosulfenyl chlorides 2a,b with iodide ion in the presence of dienes namely, 2-methyl-1,3-butadiene (isoperene), 2,3-dimethyl-1,3-butadiene, 1,2,3,4-tetrachlorocyclopentadiene, or 1,3-cyclohexadiene, respectively; or by thermolysis of oxadithiin derivatives 3a,b in the presence of the same aforementioned dienes presumably via the formation of the same intermediate A in both cases of compounds 2a,b and 3a,b. It is observed that α-chloro-β-oxosulfenyl chlorides 2a,b undergo straight forward substitution with potassium cyanide to give 8a,b. Direct oxidation of 2a,b with H2O2/AcOH affords 3,3-dichloropyran-4-ones 9a,b, while conversion of 2a,b to the sulfonamides 10a,b followed by oxidation provides 3-chloropyranones 11a,b. Antioxidant and antimicrobial evaluation of compounds 4a,b-6a,b shows moderate activiy. MIC of the derivative 6b reveals a remarkable inhibition of the pathogenic gram positive bacteria (Staphylococcus aureus ) as well as gram negative E coli.

    Chemical studies of chromanone-thiadiazole, pyridazine and thiosulfin hybrid

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    230-2363-Chlorochromanon derivatives 4a,b are reacted with hydrazine hydrate to afford 3-hydrazino-2-tetrahydro(pyran or thiopyran)chroman-4-ones 5a,b. Then compound 5a,b is reacted with carbon disulfide and acetylacetone to give 5'-thiolo - 2-tetrahydro(pyrane or thiopyran)- spiro[chroman-3,2'- [1,3,4]-thiadiazole]-4-one 6a,b and 3', 5'-dimethyl- 2- tetrahydro(pyran or thiopyran) spiro [chroman-3,2'- piprazine]-4-one 7a,b, respectively. α-Chlorosulfenyl chlorides 2a,b are treated with thioacetic acid to form α-chloroalkyl disulfides 8a,b, the latter compounds 8a,b were treated with morpholine to furnish a mixture of 1,3,4-oxadithiins 9a,b, 1,3,4,5,6-oxatetrathiocins 10a,b, 1,2,4-trithiolanes 11a,b (cis- and trans-), 1,2,4,5-tetrathiins (cis- and trans-) 12a,b. The formation of the new compounds are confirmed by spectral (IR, 1H NMR, and MS) analysis
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