Muhamed Abdelrazek - Academia.edu (original) (raw)
Papers by Muhamed Abdelrazek
Journal of the Chinese Chemical Society, 2007
... 4. Ahmed, AA; Abd El-Razek, MH; Abu Mostafa, EA; Williams, HJ; Scott, AI; Reibenspies, JH; Ma... more ... 4. Ahmed, AA; Abd El-Razek, MH; Abu Mostafa, EA; Williams, HJ; Scott, AI; Reibenspies, JH; Mabry, TJ J. Nat. Prod. 1996, 59, 1171. 5. Ahmed, AA; Abd El-Razek, MH; Nassar, MI; Izumi, S.; Ohta, S.; Hirata, T. Phytochemistry 2001, 57, 513. ...
From the ethyl acetate soluble fraction of the aerial part of Erigeron annuus, a new flavan ent-3... more From the ethyl acetate soluble fraction of the aerial part of Erigeron annuus, a new flavan ent-3,5,7,2,5-pentahydroxyflavan (14), was isolated togetherwith thirteen known compounds in- cluding six triterpenes, friedela-3-one (friedelin) (1), lupeol (2), betulinic acid (3), oleanolic acid (5), ursolonic acid (6), 3,23,28-triol olean-12-ene (7), one steroid, -sitosterol (4), three phenolic, acetovanillone (8), 2,4-dihydroxyacetophenone (9), coniferaldehyde (10), one coumarin, umbel-
ChemInform, 2010
Verticillane-Type Diterpenoids and an Eudesmanolide-Type Sesquiterpene from the Formosan Soft Cor... more Verticillane-Type Diterpenoids and an Eudesmanolide-Type Sesquiterpene from the Formosan Soft Coral Cespitularia hypotentaculata. -Four new diterpenes cespihypotin W (Ia), X (IIa), Y (IIb), and Z (Ib), possessing a verticillane skeleton and characterized by an α,β-unsaturated γ-hydroxycyclopentanone moiety, are isolated from the title plant together with a new eudesmanolide-type sesquiterpene, cespilactam A (III), containing an α,β-unsaturated γ-lactam residue. -(LIN, Y.-C.; ABD EL-RAZEK, M. H.; SHEN*, Y.-C.; Helv. Chim. Acta 93 (2010) 2, 281-289; Sch. Pharm., Coll. Med., Natl. Taiwan Univ., Taipei 100, Taiwan; Eng.) -H. Hoennerscheid 26-182
Tasks for vegetation science, 1993
Seeds of four species of Atriplex collected from Maryland and Tucson Plant Materials Centers, USA... more Seeds of four species of Atriplex collected from Maryland and Tucson Plant Materials Centers, USA, were planted under the climatic conditions of Assiut, Egypt. Species under study are:A. canescens,A. lentiformis A. polycarpa and A. amnicola. A pot experiment was carried out in a screenhouse to irrigate the transplants of one month age with saline water of different levels of salts (0, 5, 10, 20 and 30 or 40g l-1) in a sandy soil. Salinity levels were obtained using a mixture of CaCl2and NaCI in the molar ratio of 1:1. Plants were subjected to the high levels of salinity gradually by stepwise increase of the irrigation water salinity.A. amnicolawas found to be the most tolerant species. Plant fresh and dry weight did not affected by saline water up to that of 20g 1-1. Irrigation with water of 40g salts 1-1caused a reduction of 53 and 52% in fresh and dry weight of plants, respectively. Growth of the other species was decreased by irrigation with saline water of 20g salts 1-1. Reduction in plant fresh weight ofA. canescens,A. lentiformisandA. polycarpawas 42, 48 and 49%, respectively. The plant content of N, Na and K showed a varied response to salinity according to the plant species.
Gravity structures depend mainly upon its own weight to resist the effecting forces, specially up... more Gravity structures depend mainly upon its own weight to resist the effecting forces, specially upward force. Upward force can be reduced by using a drainage gallery somewhere beneath the floor of the structure. The optimum location of the drainage gallery underneath gravity dam is the goal of this study. This location is denoted by position of maximum reduction in uplift
Zeitschrift für Naturforschung. C, Journal of biosciences
Stereospecific olefin (C=C) and carbonyl (C=O) reduction of the readily available prochiral compo... more Stereospecific olefin (C=C) and carbonyl (C=O) reduction of the readily available prochiral compound ketoisophorone (2,2,6-trimethyl-2-cyclohexene-1,4-dione) (1) by Marchantia polymorpha and Nicotiana tabacum cell suspension cultures produce the chiral products (6R)-levodione (2), (4R,5S)-4-hydroxy-3,3,5-trimethylcyclohexanone (3), and (4R,6R)-actinol (4) as well as the minor components (4R)-hydroxyisophorone (5) and (4S)-phorenol (6).
Journal of Construction Engineering and Management, 2001
ABSTRACT: Many construction systems have been used to build several highway bridges and elevated ... more ABSTRACT: Many construction systems have been used to build several highway bridges and elevated roads in Egypt. Recently, the stepping shuttering system has been used in Egypt for cast-in-place concrete bridge. This system is most appropriate for concrete bridges of ...
Journal of Construction Engineering and Management, 2000
Many techniques are used in practice to construct underwater foundations, including caissons and ... more Many techniques are used in practice to construct underwater foundations, including caissons and piled foundations. The main challenge of underwater construction is cutting off water seepage so as to always provide dry working conditions. Water seepage can be eliminated by continually pressurizing inside caissons and dewatering the intercepted space of sheet-pile cofferdams. Although these methods alleviate water seepage, they have negative aspects, including unhygienic working conditions and elevated costs. This paper presents a method to partly construct the submerged pile caps above water, sink to place, and complete work in totally dry working conditions. This method adapts the lift-slab technology to lower the pile cap to the underwater permanent position. Only activities necessary to make the pile cap monolithic with the pile group are achieved after the cap is lowered in secured dry working conditions. This method was used successfully in many bridges on the Nile River in Egypt during the last decade. The method is illustrated in this paper along with the problems encountered during construction. Finally, the method is evaluated and compared with other methods.
Journal of Construction Engineering and Management, 1999
Diaphragm walls are built to exclude earth and water from an area so that work may be performed u... more Diaphragm walls are built to exclude earth and water from an area so that work may be performed under reasonably dry conditions. The range of applications for diaphragm walls includes earth-retaining and load-bearing walls for a variety of constructs such as underpasses, ...
Planta Medica, 2010
Four new oxygenated dibenzocyclooctadiene lignans, arisanschinins A-D ( 1- 4), and a new 1,4-bis(... more Four new oxygenated dibenzocyclooctadiene lignans, arisanschinins A-D ( 1- 4), and a new 1,4-bis(phenyl)-2,3-dimethylbutane lignan, arisanschinin E ( 5), together with 15 known compounds, were isolated from the EtOAc-soluble fraction of the aerial parts of SCHISANDRA ARISANENSIS Hay. The structures of 1- 5 were elucidated on the basis of extensive spectroscopic analyses, including 2D NMR (HMQC, HMBC, and NOESY) experiments. The configurations of the biphenyl and octadiene moieties were deduced from circular dichroism (CD) and NOESY spectra, respectively. Compound 1 showed significant inhibition of α-glucosidase IN VITRO. The radical-scavenging activities of these compounds were evaluated using DPPH.
Phytochemistry, 2001
From the chloroform extract of the roots of Ferula assa-foetida, two sesquiterpene coumarins desi... more From the chloroform extract of the roots of Ferula assa-foetida, two sesquiterpene coumarins designated assafoetidnol A and assafoetidnol B were isolated, in addition to six known compounds, gummosin, polyanthin, badrakemin, neveskone, samarcandin and galbanic acid. The structures of the sesquiterpenes new compounds were established by spectroscopic methods.
Phytochemistry, 2001
Two monoterpene coumarins, designated ferulagol A and B, as well as three known monoterpene couma... more Two monoterpene coumarins, designated ferulagol A and B, as well as three known monoterpene coumarins and three sesquiterpene lactones were isolated from the chloroform extract of the roots of Ferula ferulago. The structures of ferulagol A and B were determined to be 7-[(E)-3'-hydroxy-3',7'-dimethyl-4',6'-octadienyloxy]coumarin and 7-[(3'Z,5'E)-7'-hydroxy-3',7'-dimethyl-3',5'-octadienyloxy]coumarin, respectively.
Phytochemistry, 2009
Chemical investigations of aerial parts of Tephrosia purpurea yielded the rare prenylated flavono... more Chemical investigations of aerial parts of Tephrosia purpurea yielded the rare prenylated flavonoids, tephropurpulin A (1) and isoglabratephrin , in addition to a previously identified flavonoid, glabratephrin (3). Structures were established by 1D and 2D NMR spectroscopy, as well as by HR-MS analysis; for compounds 2 and 3, structures were confirmed by X-ray analysis.
Phytochemistry, 2007
Engelharquinone (1), engelharquinone epoxide (2), engelharolide (3), and engelhardic acid (4), we... more Engelharquinone (1), engelharquinone epoxide (2), engelharolide (3), and engelhardic acid (4), were isolated as naturally occurring products from a plant source, Engelhardia roxburghiana together with 20 previously known compounds, four of which were hitherto not known as plant constituents. Their structures were identified by means of spectroscopic analysis. A biological evaluation showed that three of the previously isolated antitubercular constituents [(À)-4-hydroxy-1-tetralone, 3-methoxyjuglone and engelhardione] and engelharquinone (1) exhibited moderate antitubercular activity against Mycobacterium tuberculosis 90-221387.
Pharmacognosy Research, 2010
Journal of the Chinese Chemical Society, 2007
... 4. Ahmed, AA; Abd El-Razek, MH; Abu Mostafa, EA; Williams, HJ; Scott, AI; Reibenspies, JH; Ma... more ... 4. Ahmed, AA; Abd El-Razek, MH; Abu Mostafa, EA; Williams, HJ; Scott, AI; Reibenspies, JH; Mabry, TJ J. Nat. Prod. 1996, 59, 1171. 5. Ahmed, AA; Abd El-Razek, MH; Nassar, MI; Izumi, S.; Ohta, S.; Hirata, T. Phytochemistry 2001, 57, 513. ...
From the ethyl acetate soluble fraction of the aerial part of Erigeron annuus, a new flavan ent-3... more From the ethyl acetate soluble fraction of the aerial part of Erigeron annuus, a new flavan ent-3,5,7,2,5-pentahydroxyflavan (14), was isolated togetherwith thirteen known compounds in- cluding six triterpenes, friedela-3-one (friedelin) (1), lupeol (2), betulinic acid (3), oleanolic acid (5), ursolonic acid (6), 3,23,28-triol olean-12-ene (7), one steroid, -sitosterol (4), three phenolic, acetovanillone (8), 2,4-dihydroxyacetophenone (9), coniferaldehyde (10), one coumarin, umbel-
ChemInform, 2010
Verticillane-Type Diterpenoids and an Eudesmanolide-Type Sesquiterpene from the Formosan Soft Cor... more Verticillane-Type Diterpenoids and an Eudesmanolide-Type Sesquiterpene from the Formosan Soft Coral Cespitularia hypotentaculata. -Four new diterpenes cespihypotin W (Ia), X (IIa), Y (IIb), and Z (Ib), possessing a verticillane skeleton and characterized by an α,β-unsaturated γ-hydroxycyclopentanone moiety, are isolated from the title plant together with a new eudesmanolide-type sesquiterpene, cespilactam A (III), containing an α,β-unsaturated γ-lactam residue. -(LIN, Y.-C.; ABD EL-RAZEK, M. H.; SHEN*, Y.-C.; Helv. Chim. Acta 93 (2010) 2, 281-289; Sch. Pharm., Coll. Med., Natl. Taiwan Univ., Taipei 100, Taiwan; Eng.) -H. Hoennerscheid 26-182
Tasks for vegetation science, 1993
Seeds of four species of Atriplex collected from Maryland and Tucson Plant Materials Centers, USA... more Seeds of four species of Atriplex collected from Maryland and Tucson Plant Materials Centers, USA, were planted under the climatic conditions of Assiut, Egypt. Species under study are:A. canescens,A. lentiformis A. polycarpa and A. amnicola. A pot experiment was carried out in a screenhouse to irrigate the transplants of one month age with saline water of different levels of salts (0, 5, 10, 20 and 30 or 40g l-1) in a sandy soil. Salinity levels were obtained using a mixture of CaCl2and NaCI in the molar ratio of 1:1. Plants were subjected to the high levels of salinity gradually by stepwise increase of the irrigation water salinity.A. amnicolawas found to be the most tolerant species. Plant fresh and dry weight did not affected by saline water up to that of 20g 1-1. Irrigation with water of 40g salts 1-1caused a reduction of 53 and 52% in fresh and dry weight of plants, respectively. Growth of the other species was decreased by irrigation with saline water of 20g salts 1-1. Reduction in plant fresh weight ofA. canescens,A. lentiformisandA. polycarpawas 42, 48 and 49%, respectively. The plant content of N, Na and K showed a varied response to salinity according to the plant species.
Gravity structures depend mainly upon its own weight to resist the effecting forces, specially up... more Gravity structures depend mainly upon its own weight to resist the effecting forces, specially upward force. Upward force can be reduced by using a drainage gallery somewhere beneath the floor of the structure. The optimum location of the drainage gallery underneath gravity dam is the goal of this study. This location is denoted by position of maximum reduction in uplift
Zeitschrift für Naturforschung. C, Journal of biosciences
Stereospecific olefin (C=C) and carbonyl (C=O) reduction of the readily available prochiral compo... more Stereospecific olefin (C=C) and carbonyl (C=O) reduction of the readily available prochiral compound ketoisophorone (2,2,6-trimethyl-2-cyclohexene-1,4-dione) (1) by Marchantia polymorpha and Nicotiana tabacum cell suspension cultures produce the chiral products (6R)-levodione (2), (4R,5S)-4-hydroxy-3,3,5-trimethylcyclohexanone (3), and (4R,6R)-actinol (4) as well as the minor components (4R)-hydroxyisophorone (5) and (4S)-phorenol (6).
Journal of Construction Engineering and Management, 2001
ABSTRACT: Many construction systems have been used to build several highway bridges and elevated ... more ABSTRACT: Many construction systems have been used to build several highway bridges and elevated roads in Egypt. Recently, the stepping shuttering system has been used in Egypt for cast-in-place concrete bridge. This system is most appropriate for concrete bridges of ...
Journal of Construction Engineering and Management, 2000
Many techniques are used in practice to construct underwater foundations, including caissons and ... more Many techniques are used in practice to construct underwater foundations, including caissons and piled foundations. The main challenge of underwater construction is cutting off water seepage so as to always provide dry working conditions. Water seepage can be eliminated by continually pressurizing inside caissons and dewatering the intercepted space of sheet-pile cofferdams. Although these methods alleviate water seepage, they have negative aspects, including unhygienic working conditions and elevated costs. This paper presents a method to partly construct the submerged pile caps above water, sink to place, and complete work in totally dry working conditions. This method adapts the lift-slab technology to lower the pile cap to the underwater permanent position. Only activities necessary to make the pile cap monolithic with the pile group are achieved after the cap is lowered in secured dry working conditions. This method was used successfully in many bridges on the Nile River in Egypt during the last decade. The method is illustrated in this paper along with the problems encountered during construction. Finally, the method is evaluated and compared with other methods.
Journal of Construction Engineering and Management, 1999
Diaphragm walls are built to exclude earth and water from an area so that work may be performed u... more Diaphragm walls are built to exclude earth and water from an area so that work may be performed under reasonably dry conditions. The range of applications for diaphragm walls includes earth-retaining and load-bearing walls for a variety of constructs such as underpasses, ...
Planta Medica, 2010
Four new oxygenated dibenzocyclooctadiene lignans, arisanschinins A-D ( 1- 4), and a new 1,4-bis(... more Four new oxygenated dibenzocyclooctadiene lignans, arisanschinins A-D ( 1- 4), and a new 1,4-bis(phenyl)-2,3-dimethylbutane lignan, arisanschinin E ( 5), together with 15 known compounds, were isolated from the EtOAc-soluble fraction of the aerial parts of SCHISANDRA ARISANENSIS Hay. The structures of 1- 5 were elucidated on the basis of extensive spectroscopic analyses, including 2D NMR (HMQC, HMBC, and NOESY) experiments. The configurations of the biphenyl and octadiene moieties were deduced from circular dichroism (CD) and NOESY spectra, respectively. Compound 1 showed significant inhibition of α-glucosidase IN VITRO. The radical-scavenging activities of these compounds were evaluated using DPPH.
Phytochemistry, 2001
From the chloroform extract of the roots of Ferula assa-foetida, two sesquiterpene coumarins desi... more From the chloroform extract of the roots of Ferula assa-foetida, two sesquiterpene coumarins designated assafoetidnol A and assafoetidnol B were isolated, in addition to six known compounds, gummosin, polyanthin, badrakemin, neveskone, samarcandin and galbanic acid. The structures of the sesquiterpenes new compounds were established by spectroscopic methods.
Phytochemistry, 2001
Two monoterpene coumarins, designated ferulagol A and B, as well as three known monoterpene couma... more Two monoterpene coumarins, designated ferulagol A and B, as well as three known monoterpene coumarins and three sesquiterpene lactones were isolated from the chloroform extract of the roots of Ferula ferulago. The structures of ferulagol A and B were determined to be 7-[(E)-3'-hydroxy-3',7'-dimethyl-4',6'-octadienyloxy]coumarin and 7-[(3'Z,5'E)-7'-hydroxy-3',7'-dimethyl-3',5'-octadienyloxy]coumarin, respectively.
Phytochemistry, 2009
Chemical investigations of aerial parts of Tephrosia purpurea yielded the rare prenylated flavono... more Chemical investigations of aerial parts of Tephrosia purpurea yielded the rare prenylated flavonoids, tephropurpulin A (1) and isoglabratephrin , in addition to a previously identified flavonoid, glabratephrin (3). Structures were established by 1D and 2D NMR spectroscopy, as well as by HR-MS analysis; for compounds 2 and 3, structures were confirmed by X-ray analysis.
Phytochemistry, 2007
Engelharquinone (1), engelharquinone epoxide (2), engelharolide (3), and engelhardic acid (4), we... more Engelharquinone (1), engelharquinone epoxide (2), engelharolide (3), and engelhardic acid (4), were isolated as naturally occurring products from a plant source, Engelhardia roxburghiana together with 20 previously known compounds, four of which were hitherto not known as plant constituents. Their structures were identified by means of spectroscopic analysis. A biological evaluation showed that three of the previously isolated antitubercular constituents [(À)-4-hydroxy-1-tetralone, 3-methoxyjuglone and engelhardione] and engelharquinone (1) exhibited moderate antitubercular activity against Mycobacterium tuberculosis 90-221387.
Pharmacognosy Research, 2010