Hydrolyzable Tannins of Tamaricaceous Plants. III. Hellinoyl- and Macrocyclic-Type Ellagitannins from Tamarix nilotica

Abstract

Three new hellinoyl-type ellagitannins, nilotinins M4 (7), D7 (8), and D8 (9), and a new macrocyclic-type, nilotinin D9 (10), together with eight known tannins, hirtellins B (2), C (11), and F (12), isohirtellin C (13), tamarixinin A (3), tellimagrandins I and II, and 1,2,6-tri-O-galloyl-beta-d-glucose (14), were isolated from an aqueous acetone extract of Tamarix nilotica dried leaves. Nilotinin M4 (7) is a monomeric tannin possessing a hellinoyl moiety. The structure of 8 demonstrated replacement of one of the HHDP groups at the glucose core O-4/O-6 in ordinary dimeric tannins with a galloyl moiety at O-6. This is a new structural feature among the tamaricaceous ellagitannins. On the basis of the results, reported spectroscopic assignments for 2, 3, and the macrocyclic tannins 11-13 were revised. Unusual shifts in the NMR spectra of these macrocyclic tannins are also discussed in relation to their conformations. Several tannins isolated from T. nilotica were assessed for possible cytotoxic activity against four human tumor cell lines, and nilotinin D8 (9) and hirtellin A (1) showed high cytotoxic effects.

Tamarix nilotica (Ehrenb) Bunge: A Review of Phytochemistry and Pharmacology

“…The review of literature reported the isolation of monomeric (Isohirtellin C, Remurin A-B, Gemin D, Nilotinin, Nilotinin M2-7, Hippomanin A, and Tellimagrandin I-II), dimeric (Nilotinins D1-D10, Tamarixinin A-C and Hirtellin A-D and F), trimeric (Nilotinin T1-T2, Hirtellin T1-T3) and tetrameric ellagitannins (Nilotinin Q1) from the aqueous acetone extracts of leaves of T. nilotica growing in Egypt [10,[34][35][36][37]. Interest in the ellagitannin constituents due to their marked antiviral, antimicrobial, immunomodulatory, antitumor, and hepatic protective activities, which are largely dependent on the tannin structures [38] (Figure 3).…”

“…Ellagitannins from the leaves of T. nilotica grown in Egypt were reported to exhibit significant host-mediated antitumor activities against sarcoma-180 in mice and strong cytotoxic effects with higher tumor specificity against four tumor cell lines [35,37]. T. nilotica showed a selective cytotoxic potential against liver (HUH-7), colon (HCT-116), lung and breast (MCF-7) carcinoma cell, while being non-toxic to other cancer cells [9,40].…”

Tannin Fingerprinting in Vegetable Tanned Leather by Solid State NMR Spectroscopy and Comparison with Leathers Tanned by Other Processes

“…As in the condensed tannin cases, pure hydrolyzable tannin spectra reflect the chemistry of each [32][33][34][35]. Again the fingerprint of each tannin manifests itself clearly in the spectrum of each respective tanned leather.…”

Phenolic content, radical scavenging activity and cytotoxicity of Tamarix nilotica (Ehrenb.) bunge growing in Egypt

“…Roots revealed the presence of gallic acid derivatives, a lignan (syringaresinol) and isoferulic acid, niloticol, and 3-hydroxy-4-methoxycinnamaldehyde (Barakat et al, 1987). Leaves revealed the presence of nilotinins M1, M4, D2, D3, D7, D8, D9, hirtellins B, C, F, tamarixinin A, 1,2,6-tri-O-galloyl-D-glucose, methyl ferulate 3-O-sulphate, coniferyl alcohol 4-O-sulphate, kaempferol 4'-methyl ether, tamarixetin and quercetin 3-O-beta-D-glucupyranuronide (Orabi et al, 2009(Orabi et al, , 2010Abouzid et al, 2009). Moreover, flowers revealed isolation of the methyl and ethyl esters of gallic acid, pmethoxygallic acid, kaempferol, quercetin 3-Oglucuronides, the 3-O-sulphated kaempferol 7,4'-dimethyl ether and the free flavonols, besides the digalloylglucose and niloticin (Nawwar et al, 1982(Nawwar et al, , 1984aNawwar and Souleman, 1984).…”

“…Antioxidant and hepatoprotective activities were evaluated for total flower extract (Abouzid et al, 2008;Abouzid and Sleem, 2011), moreover, nilotinin D8 and hirtellin A isolated from leaf extract were found active against the human oral tumor cell lines, human squamous cell carcinoma (HSC-2, HSC-3, and HSC-4) and human promyelocytic leukemia (HL-60) cells (Orabi et al, 2010).…”