• Constituents of Plants Growing in Qatar, Part XXVI: Phytochemical investigation of Rumex vesicarius 

      Al Easa, Hala S.; Rizk, Abdel-Fattah M.; Hussiney, Hussiney A. (1995 , Article)
      The study of Rumex vesicarius revealed the isolation and identification of four anthraquinones (chrysoplanol (I), emodin (II), physcion (III) and rhein (IV) and seven flavonoids (apigenin (V), isoorientin (VI), isovitesin ...
    • Fatty acid composition of twelve algae from the Coastal Zones of Qatar 

      Heiba, Helmi I.; Al-Easa, Hala S.; Rizk, Abdel-Fattah M. ( Kluwer Academic Publishers , 1997 , Article)
      Fatty acid composition of twelve algal species from two different classes were determined. Three Chlorophyta species(Axetabularia calyxulux, Cladophors sericoides and Dictyosphaeria cavernosa) and nine Phaephyta species ...
    • Flavonoids from Centaurea sinaica 

      Al-Easa, Hala S.; Kamel, Alaa; Rizk, Abdel-Fattah M. (1992 , Article)
      Four Newly isolated flavonoids from Centaurea sinaica
    • Guaianolides from Picris radicata 

      Al-Easa, Hala S.; Rizk, Abdel-Fattah M.; Ahmed, Ahmed A. ( Elsevier Science Ltd. , 1996 , Article)
      The methylene chloride-methanol (1:1) extract of the aerial parts of Picris radicata Forssk afforded two new guaianolides. The structures were established from spectral data.
    • Triterpenoids from Salvia aegyptiaca 

      Bruno, Maurizio; Ciriminna, Rosaria; Al-Easa, Hala S.; Rizk, Abdel-Fattah M. (1993 , Article)
      Newly isolated secondary metabolites from Salvia aegyptiaca growing in Qatar