title: Hydrolyzable tannins of tamaricaceous plants. V. Structures of monomeric-trimeric tannins and cytotoxicity of macrocyclic-type tannins isolated from Tamarix nilotica (1).
abstract: Three new ellagitannin monomers, nilotinins M5-M7 (1-3), a dimer, nilotinin D10 (4), and a trimer, nilotinin T1 (5), together with three known dimers, hirtellin D (7) and tamarixinins B (8) and C (9), and a trimer, hirtellin T2 (6), were isolated from Tamarix nilotica dried leaves. The structures of the tannins were elucidated by intensive spectroscopic methods and chemical conversions into known tannins. The new trimer (5) is a unique macrocyclic type whose monomeric units are linked together by an isodehydrodigalloyl and two dehydrodigalloyl moieties. Additionally, dimeric and trimeric macrocyclic-type tannins isolated from T. nilotica in this study were assessed for possible cytotoxic activity against four human tumor cell lines. Tumor-selective cytotoxicities of the tested compounds were higher than those of synthetic and natural potent cytotoxic compounds, including polyphenols, and comparable with those of 5-fluorouracil and melphalan.
authors.affiliation: Faculty of Pharmacy, Al-Azhar University, Assiut, Egypt.
authors.forename: Mohamed A A
authors.initials: MA
authors.lastname: Orabi
authors.forename: Shoko
authors.initials: S
authors.lastname: Taniguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakagami
authors.forename: Morio
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Hatano
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004534:Egypt; D005472:Fluorouracil / Q000494:pharmacology; D006801:Humans; D047348:Hydrolyzable Tannins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008558:Melphalan / Q000494:pharmacology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D059808:Polyphenols / Q000494:pharmacology; D032363:Tamaricaceae / Q000737:chemistry*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D047348:Hydrolyzable Tannins; D059808:Polyphenols; D008558:Melphalan; D005472:Fluorouracil