Mamdouh N. Samy

Chemical constituents from Chorisia chodatii flowers and their biological activities

From the flowers of Chorisia chodatii Hassl. (family: Bombacaceae), seventeen compounds were isolated and identified, including: two sterols, β-sitosterol (1) and β-sitosterol 3-O-β-D-glucopyranoside (10); two furanoids, 5-hydroxymethyl furfural (3) and (3R,4R,5S)-3,4-dihydroxy-5-methyl-dihydrofuran-2-one (12); two coumarins, scopoletin (8) and aesculetin (9); four phenolic acids and esters, ethyl vanillate (4), vanillic acid (5), protocatechuic acid ethyl ester (6) and p-hydroxy benzoic acid (7); five flavonoids, kaempferol 3-O-β-D-(6″-acetyl)-glucopyranoside (13), kaempferol 3-O-β-D-(6″-E-p-coumaroyl)-glucopyranoside (14), kaempferol 3-O-β-D-glucopyranoside (15), luteolin 7-O-β-D-glucopyranoside (16) and apigenin 7-O-neohesperidoside (17), in addition to mono-octyl phthalate (2) and succinic acid (11). All the isolated metabolites were reported for the first time from this plant, and among them, compounds (3), (4), (6), (7), (12) and (13) were isolated for the first time from family Bombacaceae. Besides, this is the first report for isolation of (2) in a pure form from a natural source. These phytochemical data revealed important chemotaxonomic value and may broaden the use of this plant in future phytotherapy. Moreover, all of the obtained phytocompounds were evaluated for their DPPH free radical scavenging properties and cytotoxic activities against the human lung cancer cell line A549.

Chodatiionosides A and B: two new megastigmane glycosides from Chorisia chodatii leaves

Phytochemical investigation of Chorisia chodatii Hassl. leaves led to the isolation of an unusual rearranged megastigmane glycoside; chodatiionoside A (1) and another new megastigmane glycoside; chodatiionoside B (2), together with three known megastigmane glycosides (3–5) and one known flavonoid glycoside (6). Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments (1H, 13C, DEPT, COSY, HSQC and HMBC) in combination with HR-ESI–MS, CD and modified Mosher’s method. As a result, chodatiionoside A has been elucidated as a first example of an unusual rearranged form of megastigmane.

Amphipaniculosides A-D, triterpenoid glycosides, and amphipaniculoside E, an aliphatic alcohol glycoside from the leaves of Amphilophium paniculatum.

Four new triterpenoids; One oleanane-, one ursane- and two cycloartane-type triterpenoids, named amphipaniculosides A-D, in addition to one new aliphatic alcohol glycoside, named amphipaniculoside E, were isolated from the 1-BuOH fraction of the leaves of Amphilophium paniculatum (L.) Kunth., together with five known compounds, (+)-lyoniresinol 3α-O-β-D-glucopyranoside, (-)-lyoniresinol 3α-O-β-D-glucopyranoside, acteoside (verbascoside), isoacteoside (isoverbascoside), and luteolin 7-O-β-D-glucopyranoside. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments ((1)H, (13)C, DEPT, COSY, ROESY, HSQC, HMBC) in combination with HR-ESI-MS and by comparisons of their physical and spectroscopic data with literature values.

Effects of Hepatoprotective Compounds from the Leaves of Lumnitzera racemosa on Acetaminophen-Induced Liver Damage in Vitro

Phytochemical investigation of the n-BuOH fraction of the mangrove plant Lumnitzera racemosa WILLD. (Combretaceae) led to the isolation of one new flavonoid glycoside; myrcetin 3-O-methyl glucuronate (1), one new phenolic glycoside; lumniracemoside (2) and one new aliphatic alcohol glycoside; n-hexanol 1-O-rutinoside (3), in addition to seven known compounds (4-10). The structures of these compounds were determined by spectroscopic analyses (UV, IR, high resolution-electrospray ionization (HR-ESI)-MS, one- and two-dimensional (1D- and 2D)-NMR). Compound 7 showed the highest hepatoprotective activity against acetaminophen-induced hepatotoxicity using human HepG2 cells at protection % value of 34.2±3.1%, while compounds 1, 2, 3, 6, and 9 showed weak to moderate hepatoprotective activity (11.6-18.9%). Almost all of these compounds showed stronger 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared with the standard Trolox. These results suggest the usefulness of this plant extract and the isolated compounds as promising hepatoprotective agents.

CHEMICAL CONSTITUENTS FROM THE LEAVES OF Ruellia tuberosa

, 557 (2002).1) Department of Pharmacognosy, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi,Minami-ku, 734-8553, Hiroshima, Japan, fax: +81-82-257-5335, e-mail: hotsuka@hiroshima-u.ac.jp; 2) Department ofPharmacognosy, Faculty of Pharmacy, Minia University, 61519, Minia, Egypt. Published in