Elisabeth Seguin
University of Rouen
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Featured researches published by Elisabeth Seguin.
Phytochemistry | 2009
Simon Suh Awanchiri; Hanh Trinh-Van-Dufat; Jovita Chi Shirri; Marlise Diane Jiofack Dongfack; Guy Merlin Nguenang; Sabrina Boutefnouchet; Zacharias Tanee Fomum; Elisabeth Seguin; Philippe Vérité; François Tillequin; Jean Wandji
The air-dried stems and ripe fruit of Drypetes inaequalis Hutch. (Euphorbiaceae) were studied. Four triterpene derivatives, characterized as lup-20(29)-en-3beta,6alpha-diol, 3beta-acetoxylup-20(29)-en-6alpha-ol, 3beta-caffeoyloxylup-20(29)-en-6alpha-ol and 28-betad-glucopyranosyl-30-methyl 3beta-hydroxyolean-12-en-28,30-dioate along with 10 known compounds were isolated from the whole stems. One triterpene, characterized as 3alpha-hydroxyfriedelan-25-al along with six known compounds were isolated from the ripe fruit. Their structures were established on the basis of spectroscopic analysis and chemical evidence. The triterpenes were tested for antimicrobial activity against some Gram-positive and Gram-negative bacteria, and two of them appeared to be modestly active.
The Journal of Antibiotics | 2002
Lynda Lamari; Abdelghani Zitouni; Tahar Dob; Nasserdine Sabaou; Ahmed Lebrihi; Pierre Germain; Elisabeth Seguin; François Tillequin
Three new natural dithiopyrrolone antibiotics, 3-methyl-2-butenoylpyrrothine (1), tigloylpyrrothine (2), and n-butyropyrrothine (3) were isolated along with the known isobutyropyrrothine (4) and thiolutin (5) from the fermentation broth of Saccharothrix sp. SA 233. The structures of the novel compounds were established on the basis on their spectral data.
Phytochemistry | 2003
Jean Wandji; François Tillequin; Dulcie A. Mulholland; Jovita Chi Shirri; Nole Tsabang; Elisabeth Seguin; Philippe Vérité; Francine Libot; Zacharias Tanee Fomum
Chemical studies of the EtOAc extract of Gambeya boukokoensis Aubr. et Pellegr. stem bark led to the isolation of eight compounds. Three of them were elucidated as new compounds and designated as: gamboukokoensein A, 1alpha,2alpha,3beta,19alpha,23-pentahydroxyurs-12-en-28-oic acid; gamboukokoenside A, 2beta,3beta,6beta,28-tetrahydroxyolean-12-en-23-oic acid 23-O-alpha-L-arabinopyranosyl ester and gamboukokoenside B, 6beta,28-dihydroxy-3-oxoolean-12-en-23-oic acid 23-O-alpha-L-arabinopyranosyl ester. The other five compounds were known and identified as myrianthic acid, protobassic acid, oleanolic acid, erythrodiol and chondrillasterol. Their structures were elucidated on the basis of one and two dimensional NMR spectroscopic techniques, FABMS, ESMS and chemical evidence.
Chemistry of Natural Compounds | 2003
Fadila Benayache; A. Bentamene; Kamel Medjroubi; Elisabeth Seguin; François Tillequin
Ain l Bey, 25000 Constantine, Algerie; Fax: 213 31 62 49 12 , e-mail: s.akkal@caramail.com; 2) Laboratoire de Pharmacognosie UFR de medecine et pharmacie, Rouen, France; 3) Laboratoire de Pharmacognosie, URA au CNRS 8638, Faculte de Pharmacie, Universite Rene Descartes Paris V, Paris, France. Published from Khimiya Prirodnykh Soedinenii, No. 2, pp. 165-166, MarchApril, 2003. Original article submitted February 25, 2003.
Journal of Industrial Microbiology & Biotechnology | 2007
Boubekeur Badji; Abdellah Mostefaoui; Nasserdine Sabaou; Ahmed Lebrihi; Florence Mathieu; Elisabeth Seguin; François Tillequin
An actinomycete strain NM94 was isolated from a Saharan soil sample by a dilution agar plating method using chitin-vitamins B medium supplemented with penicillin. The strain presented the morphological and chemical characteristics of the genus Nonomuraea. On the basis of 16S rDNA analysis and physiological tests, this isolate was found to be quite different from the known species of Nonomuraea and might be new. The strain NM94 secreted several antibiotics on yeast extract malt extract glucose medium that were active against some Gram-positive bacteria, yeast, and fungi. The antibiotics were extracted with dichloromethane and detected by bioautography on silica gel plates using Mucorramannianus and Bacillussubtilis as the test organisms. Among these antibiotics, a complex called 94A showed interesting antifungal activity. It was selected and purified by reverse-phase HPLC. This complex was composed of five compounds. Spectroscopic studies by infrared, mass, and 1H NMR of the compounds were carried out. Initial results showed that these molecules differed from the known antibiotics produced by other Nonomuraea species.
Zeitschrift für Naturforschung C | 2003
Naòma Benkiki; Zahia Kabouche; François Tillequin; Philippe Vérité; Elizabeth Chosson; Elisabeth Seguin
Abstract Hyperfoliatin, a new polyisoprenylated phloroglucinol derivative was isolated from the aerial parts of Hypericum perfoliatum (Clusiaceae) collected in Algeria. The structure of hyperfoliatin was elucidated on the basis of its spectral data, mainly MS and multiple-pulse NMR.
Phytochemistry | 2003
Jean Wandji; François Tillequin; Dulcie A. Mulholland; Agathe D. Temgoua; Jean-D. Wansi; Elisabeth Seguin; Z. Tanee Fomum
The methanol extract of the dried stem bark of Drypetes armoracia Pax & Hoffm. afforded two compounds named drypearmoracein A, (E)-4,5,6,7-tetrahydroxy-2-benzylhept-2-enoic acid and drypearmoracein B, 2,3-dihydroxy-9,10-tetrahydroanthra-1,4-quinone along with five known compounds: friedelan-3 beta-ol, friedelin, friedelane-3,7-dione, drypemolundein B and beta-stigmasterol. Their structures were established on the basis of spectroscopic analysis and chemical evidence.
Current Medicinal Chemistry | 2002
Sylvie Michel; Elisabeth Seguin; François Tillequin
Acronycine is active against a broad spectrum of solid tumors. Structure activity relationships demonstrated the crucial role of the 1,2-double bond. A hypothesis of bioactivation into 1,2-epoxide led to the development of a series of 1,2-dihydroxy-1,2-dihydroacronycine and 1,2-dihydroxy-1,2-dihydrobenzo[b]acronycine diesters that exhibited an increased potency when compared with the parent compound.
International Journal of Molecular Sciences | 2011
Anne-Sylvie Fabiano-Tixier; Abdelhakim Elomri; Axelle Blanckaert; Elisabeth Seguin; Emmanuel Petitcolas; Farid Chemat
Quinas contains several compounds, such as quinoline alkaloids, principally quinine, quinidine, cinchonine and cichonidine. Identified from barks of Cinchona, quinine is still commonly used to treat human malaria. Microwave-Integrated Extraction and Leaching (MIEL) is proposed for the extraction of quinoline alkaloids from bark of Cinchona succirubra. The process is performed in four steps, which ensures complete, rapid and accurate extraction of the samples. Optimal conditions for extraction were obtained using a response surface methodology reached from a central composite design. The MIEL extraction has been compared with a conventional technique soxhlet extraction. The extracts of quinoline alkaloids from C. succirubra obtained by these two different methods were compared by HPLC. The extracts obtained by MIEL in 32 min were quantitatively (yield) and qualitatively (quinine, quinidine, cinchonine, cinchonidine) similar to those obtained by conventional Soxhlet extraction in 3 hours. MIEL is a green technology that serves as a good alternative for the extraction of Cinchona alkaloids.
Fitoterapia | 1999
Fadila Benayache; Samir Benayache; Kamel Medjroubi; Maurice Jay; François Tillequin; Elisabeth Seguin
A new flavone glycoside, hispidulin 7-O-methylglucuronide (1) has been isolated from the aerial part of Centaurea furfuracea.