Phytochemistry of Tunisian Plants

Études biologique et chimique de la plante Prasium major poussant en Tunisie. Structure d'un heteroside steroidique et d'un steroide. Identification de constituents de la fraction volatile, M.A. Mahjoub; H. Ben Jannet; P.J.M. Abreu; Z. Mighri, J. Soc. Chim. Tun., 2002, 4, 1419.
Abstract: b-Sitosterol glycoside and ergosterol peroxide have been isolated and identified for the first time in the aerial part of the plant Prasium majus. Analysis by GCMS of the volatile fraction extracted from the same plant has permitted the identification of 37 natural products, showing in mixture an antibacterial activity against Staphylococcus aureus.
*Terpenoids from the fruit barks of Periploca laevigata* growing in Tunisia*, F. Hichri, O. Hammouda, H. B. Jannet, Z. Mighri, P.M. Abreu; J. Soc. Chim. Tun., 2002*, 4, 1565.
Abstract: Three compounds previously identified in other natural sources, have been isolated from the first time from the fruit barks of Periploca laevigata (Asclepiadaceae): oleanolic acid 1, maslinic acid 2 and b-sitosterol-3-b-D-glucoside 4. b-Amyrine has been also re-isolated. Their structures have been establishd by spectroscopic procedures.
*Triterpénes isolés des écorces des fruits de la plante Periploca laevigata* poussant en Tunisie*, F. Hichri; H. B. Jannet; P.M. Abreu; Z. Mighri; J. Soc. Alg.* Chim.,2003, 13,187. PDF
Abstract: Three triterpenes: 12a-hydroxy-d-lactone of oleanolic acid 1, arjunolic acid 2 and asiatic acid 3 have been identified for the first time in the fruit barks of Periploca laevigata (Asclepiadaceae). Their structures have been established via their acetylated and methylated derivatives using different spectroscopic procedures.
Antioxidant Phenolic Glycosides from *Moricandia arvensis, H. Braham; Z. Mighri; H. B. Jannet; S. Matthew; P. M. Abreu; J. Nat. Prod.,* 2005, 68, 517-522. DOI.
Abstract: The new phenolic glycosides quercetin 3,4'-di-O-β-D-glucopyranoside-7-O-α-L-rhamnopyranoside (moricandin) (1), β-D-glucopyranosyl 4-O-β-D-glucopyranosylcaffeate (2), methyl 3-O-β-D-glucopyranosyl-5-hydroxycinnamate (3), and β-D-glucopyranosyl 4-O-β-D-glucopyranosylbenzoate (4), together with the previously known β-D-glucopyranosyl 4-hydroxybenzoate (5), methyl 4-O-β-D-glucopyranosylcaffeate (6), 1-O-caffeoyl-β-D-glucopyranoside (7), and 2-phenylethyl-β-D-glucopyranoside (8), were isolated from the flowers of Moricandia arvensis. Their structures were elucidated by extensive spectroscopic analysis and chemical methods. Compounds 1-8 were evaluated for antioxidant activity using DPPH, TEAC, and reducing power assays, where the caffeic acid derivative 7 and the quercetin triglycoside 2 proved to possess the most potent scavenging activity.

Structure d'un coumarino-lignane isolé de la partie aérienne de la plante Salsola tetrandra, M.H. Oueslati, H. Ben Jannet, P. Abreu, Z. Mighri, J. Soc. Alger. Chim., 2004, 14, 181. Link.
Abstract: Cleomiscosin D (1), 4-hydroxybenzaldehyde (2), and 4-methoxybenzylic alcohol (3) have been isolated for the first time from the ethyl acetate extract of Salsola tetrandra aerial parts (Chenopodiacae). Their structures have been established by spectroscopic methods, using 2D NMR for compound 1 via its acetylated derivative 1a, as well as by comparison with literature data.

Alcools tetrahydropyraniques polyacetyleniques antibacteriend de la plante Rantherium suaveolens poussant dans le Sud Tunisien, M.H. Oueslati, H. Ben Jannet, P. Abreu, Z. Mighri, J. Soc. Alger. Chim., 2004, 14, 245. Link.
Abstract: The bio-guided chromatographic separations which have been carried out on the ethyl acetate extract of the above-ground parts of Rantherium suaveolens (Compositae) growing in the south of Tunisia led to the characterisation by GCMS of most components of its apolar fractions, and the isolation for the first time of two polyacetylenic tetrahydropyranic alcohols (2S, 3R,1’E,7’E)-tétrahydro-2-(nona- 1’,7’-diène-3’,5’-diynyl)pyran-3-ol (1) and (2S, 3R,1’E)-tétrahydro-2-(nona-1’-ène-3’,5’,7’-triynyl)pyran-3-ol (2) (ichthyothereol). Their structures have been established by spectroscopic means (1 and 2D NMR, UV, IR, EIMS) as well as by comparison with literature data. The antibacterial effect of compounds 1 and 2 has been also studied. Some interesting results have been noted and discussed.

*New Ceramides from Rantherium suaveolens,* M. Habib Oueslati, H. Ben Jannet, Zine Mighri, Pedro M. Abreu, Lipids, 40, 1075 (2005). PDF
Abstract: A mixture of five new ceramides was isolated from the aerial parts of Rantherium suaveolens and characterized by spectroscopic and chemical methods. Their structures were elucidated by spectroscopic and chemical methods as (2S,3S,4R,2´R,14E)-2-(2´-hydroxydocosanoylamino)-14-octadecene-1,3,4-triol, (2S,3S,4R,2´R,14E)-2-(2´-hydroxytricosanoylamino)-14-octadecene-1,3,4-triol, (2S,3S,4R,2´R,14E)-2-(2´-hydroxytetracosanoylamino)-14-octadecene-1,3,4-triol, (2S,3S,4R,2´R,14E)-2-(2´-hydroxypentacosanoylamino)-14-octadecene-1,3,4-triol, and (2S,3S,4R,2´R,14E)-2-(2´-hydroxyhexacosanoylamino)-14-octadecene-1,3,4-triol.
Antioxidant compounds from Ebenus pinnata, Pedro M. Abreu, Hatem Braham, Hichem Ben Jannet, Zine Mighri, Susan Matthew, Fitoterapia, 78, 32 (2007). PDF
Abstract: Activity-guided fractionation of the methanol extract of Ebenus pinnata aerial parts led to the isolation of ombuoside (1), kaempferol 3-O-rutinoside (2), rutin (3), catechin (4), and picein (5), along with b-sitosterol and b-sitosterol glucoside. Compounds 1-4 showed significant antioxidant activity in the DPPH, TEAC, and reducing power assays.
Phytochemical Constituents from Salsola tetrandra, M. Habib Oueslati, Hichem Ben Jannet, Zine Mighri, J. Chriaa, and Pedro M. Abreu, J. Nat. Prod., 2006, 69, 1366-1369. PDF
Abstract: The new norisoprenoid 3b-hydroxy-5a,6a-epoxy-b-ionone-2a-O-b-D-glucopyranoside (1), and the long-chain hydroxy fatty acids 9,12,13-trihydroxyoctadeca-10(E),15(Z)-dienoic acid (2), and 9,12,13-trihydroxyoctadeca-10(E)-dienoic acid (3), were isolated from Salsola tetrandra aerial parts, together with 3,4,5-trimethoxyphenyl-b-D-glucopyranoside (4), 9-hydroxylinaloyl glucoside (5), taxiphyllin (6), trans-N-feruloyltyramine (7), and S-(-)-trans-N-feruloyloctopamine (8). Their structures were elucidated by extensive spectroscopic analysis and chemical methods. Compounds 6 and 8 displayed mild antibacterial activity against Staphylococcus aureus, whereas compound 6 showed the highest activity in the Artemia salina bioassay.
A new C₉ nor-isoprenoid glucoside from Rantherium suaveolens, M. Habib Oueslati, H. Bem Jannet, Zine Mighri, Susan Matthew, and Pedro Abreu, Natural Product Research, 21, 884 (2007).
Abstract: The new C₉ nor-isoprenoid 3-methyl-octa-1,5-diene-7-one-3-O-b-D-glucopyranoside, named as ranthenone glucoside (1), together with the previously known 9-hydoxylinaloyl glucoside (2), sitosterol-3b-O-[6´-palmitoyl-b-D-glucopyranoside] (3), scopoletin (4), fraxetin (5), and scopolin (6), were isolated from the aerial parts of Rantherium suaveolens. The structures of these compounds were elucidated by extensive spectroscopic analysis.