Dalia AlMahdy | Cairo University (original) (raw)

Papers by Dalia AlMahdy

The phytoconstituents of essential oil and ethanol oleoresin of fresh and dry rhizomes of turmeri... more The phytoconstituents of essential oil and ethanol oleoresin of fresh and dry rhizomes of turmeric (Curcuma longa Linn.) were analyzed by GC-MS. The major constituents were aromatic-turmerone (24.4%), alphaturmerone (20.5%) and beta-turmerone (11.1%) in fresh rhizome and aromatic-turmerone (21.4%), alpha-santalene (7.2%) and aromatic-curcumene (6.6%) in dry rhizome oil. Whereas, in oleoresins, the major components were alpha-turmerone (53.4%), beta-turmerone (18.1%) and aromatic-turmerone (6.2%) in fresh and aromatic-turmerone (9.6%), alpha-santalene (7.8%) and alpha-turmerone (6.5%) in dry rhizome. Results showed that alpha-turmerone, a major component in fresh rhizomes is only minor one in dry rhizomes. Also, the content of beta-turmerone in dry rhizomes is less than a half amount found in fresh rhizomes. The antioxidant properties have been assessed by various lipid peroxidation assays as well as DPPH radical scavenging and metal chelating methods. The essential oil and ethanol oleoresin of fresh rhizomes have higher antioxidant properties as compared dry ones. j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / f o o d c h e m t o x

Scientia …, Jan 1, 2011

A major development over the past two decades has been the realization that free radical induced ... more A major development over the past two decades has been the realization that free radical induced lipid peroxidation and DNA damage are associated with major health problems, e.g. cancer and ageing. Plant-derived antioxidants are increasingly found beneficial in protecting against these diseases. Celtis australis L. and Celtis occidentalis L. are two plants that have a variety of uses in folk medicine but have not been evaluated before for their antioxidant and cytotoxic properties. Therefore, the extracts of both plants’ leaves were investigated for these activities, as well as isolation of the bioactive compounds responsible for the activities. Molecular structures of the compounds were elucidated by UV, HRESIMS, 1D (1H and 13C) and 2D (1H-13C HSQC and 1H-13C HMBC) NMR analyses. The ethanolic and aqueous extracts, n-butanol fractions and the isolated major compound were tested for their antioxidant activity using DPPH radical scavenging assay, xanthine oxidase-induced generation of superoxide radical and lipid peroxidation assay by thiobarbituric acid-reactive substances (TBARS) method using rat tissue homogenates. Cytotoxic activities were studied using standard MTT assay. A novel flavonoid C-triglycoside, 4-α-rhamnopyranosyl-2″-O-β-d-galactopyranosylvitexin, was isolated from both plants’ leaves, together with seven known flavonoids. The n-butanol fractions and the major compound 2″-O-β-galactopyranosylvitexin showed significant antioxidant activities, more pronounced than the tested standards BHT and dl-α-tocopherol in most tests. All extracts showed variable cytotoxic activities. This study provides strong evidence for the antioxidant and cytotoxic activities of the extracts of Celtis australis L. and Celtis occidentalis L. leaves, which were attributed to the polar n-butanol fractions and the major isolated flavonoid 2″-galactosylvitexin.

Bulletin of Faculty of …, Jan 1, 2011

Abstract Celtis australis L. and Celtis occidentalis L. are deciduous ornamental trees, grown in ... more Abstract Celtis australis L. and Celtis occidentalis L. are deciduous ornamental trees, grown in Egypt. This study presents a comparative investigation of the botanical features of the stems, stem barks and leaves of both plants. Furthermore, the DNA of both plants was ...

"Two novel acylated flavonol glycosides were isolated from the n-butanol fraction of the ethanoli... more "Two novel acylated flavonol glycosides were isolated from the n-butanol fraction of the ethanolic extract of Platanus orientalis
L. leaves. They were identified as kaempferol-3-O-(2´´´-p-E-coumaroylrhamnosyl)(1´´´→6´´)-[β-D-glucopyranosyl-
(1´´´´→2´´)-β-D-glucopyranoside]-7-O-α-L-rhamnopyranoside, and quercetin-3-O-(2´´´-p-E-coumaroylrhamnosyl)(1´´´→6´´)-
[β-D-glucopyranosyl-(1´´´´→2´´)-β-D-glucopyranoside]-7-O-α-L-rhamnopyranoside. Their structures were established on the
basis of detailed spectral analysis."

"A new flavonoid glycoside, 5,7,4´-trihydroxy-3,6-dimethoxyflavone-3´-O-β-D-xylopyranoside (axill... more "A new flavonoid glycoside, 5,7,4´-trihydroxy-3,6-dimethoxyflavone-3´-O-β-D-xylopyranoside (axillarin-3´-O-β-Dxylopyranoside),
was isolated from the ethyl acetate fraction of the ethanolic extract of Platanus orientalis L. leaves, along
with nine known flavonoid aglycones and glycosides, a phenolic acid and a phenolic acid derivative. Their structures were
established on the basis of detailed spectral analysis. The total ethanolic, aqueous and ethyl acetate extracts of the leaves were
tested for antihepatotoxic, antioxidant and cytotoxic activities. The extracts were found to be effective in protection against
CCl4 liver injury by significantly lowering alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline
phosphatase (ALP) levels. The extracts also significantly restored depleted levels of glutathione, indicating a strong antioxidant
activity, while they showed variable cytotoxic activity."

Scientia …, Jan 1, 2011

Bulletin of Faculty of …, Jan 1, 2011