Yasser Abdelaal Selim

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Investigation of the aerial parts of the Egyptian medicinal plant Ammi majus L. led to isolation of new coumarin, 6-hydroxy-7-methoxy-4 methyl coumarin (2) and 6-hydroxy-7-methoxy coumarin (3); this is the first time they have been isolated from this plant. The structures of the compounds (2 &3) were elucidated by spectroscopic data interpretation and(More)
Since the early 1990s, Egypt has experienced rapid and substantial aggravation of the unemployment problem. And despite consensus on the adverse economic, social and political implications of this problem, the present study starts from the premise that the real danger of unemployment lies in the fact that it reflects low and inefficient levels of investment(More)
A new isoflavonoid, 5,6-dimethoxy-2',3'-methylenedioxy-7-C-β-d-gluco-pyranosyl isoflavone was isolated from the seeds of Lepidium sativum L. along with two known isoflavonoids, 7-hydroxy-4',5,6-trimethoxyisoflavone and 7-hydroxy-5,6-dimethoxy-2',3'-methylenedioxyisoflavone. The structures of all compounds were elucidated with NMR spectrometry. Compounds 1,(More)
The local Egyptian peels of Malus domestica were extracted successively with absolute ethanol and partitioned sequentially with n-hexane, chloroform and methanol. Friedelin (1) was isolated from the n-hexane fraction and betulinic acid (2) from the chloroform fraction. The new compounds 2α-hydroxy-3-oxo-lup-12(13), 20(29)-dien-27, 28-dioic acid (3) and 2α,(More)
A series of novel coumarin derivatives were synthesized from 6-hydroxy-7-methoxy-4-methyl coumarin which was isolated from the aerial parts of the Egyptian medicinal plant Ammi majus L. (Apiaceae). The key intermediate 3-amino-5-methoxy-1-(4-methoxyphenyl)-10-methyl-8-oxo-1,8-dihydropyrano[3,2-f]chromene-2-carbonitrile (3c) was obtained in one-pot synthesis(More)
The structure of the natural dipyranocoumarin dipetalolactone has been confirmed by an unambiguous synthetic route from resorcinol. This sequence was initiated by a pyran ring formation step which introduced the 3-chloro-3-methylbut-1-yne moiety. Then, the expected product undergoes a Fremy's salt-meditated oxidative addition followed by ring closure to(More)
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