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)
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 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)
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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