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Polyphenols have a variety of phenolic hydroxyl and carbonyl functionalities that enable them to scavenge many oxidants, thereby preserving the human redox balance and preventing a number of oxidative stress-related chronic degenerative diseases. In our ongoing investigation of polyphenol-rich plants in search of novel molecules, we resumed the investigation of Lawsonia inermis L. (Lythraceae) or henna, a popular ancient plant with aesthetic and therapeutic benefits. The leaves' 70% aq acetone extract was fractionated on a Diaion HP-20 column with different ratios of H2O/an organic solvent. Multistep gel chromatographic fractionation and HPLC purification of the Diaion 75% aq MeOH and MeOH fractions led to a new compound (1) along with tannin-related metabolites, benzoic acid (2), benzyl 6′-O-galloyl-β-D-glucopyranoside (3), and ellagic acid (4), which are first isolated from henna. Repeating the procedures on the Diaion 50% aq MeOH eluate led to the first-time isolation of two O-glucosidic ellagitannins, heterophylliin A (5), and gemin D (6), in addition to four known C-glycosidic ellagitannins, lythracin D (7), pedunculagin (8), flosin B (9), and lagerstroemin (10). The compound structures were determined through intensive spectroscopic investigations, including HRESIMS, 1D (1H and 13C) and 2D (1H–1H COSY, HSQC, HMBC, and NOESY) NMR, UV, [α]D, and CD experiments. The new structure of 1 was determined to be a megastigmane glucoside gallate; its biosynthesis from gallic acid and a β-ionone, a degradative product of the common metabolite β-carotin, was highlighted. Cytotoxicity investigations of the abundant ellagitannins revealed that lythracin D2 (7) and pedunculagin (8) are obviously more cytotoxic (tumor specificity = 2.3 and 2.8, respectively) toward oral squamous cell carcinoma cell lines (HSC-2, HSC-4, and Ca9-22) than normal human oral cells (HGF, HPC, and HPLF). In summary, Lawsonia inermis is a rich source of anti-oral cancer ellagitannins. Also, the several discovered polyphenolics highlighted here emphasize the numerous biological benefits of henna and encourage further clinical studies to profit from their antioxidant properties against oxidative stress-related disorders. [ABSTRACT FROM AUTHOR]

Dietary fruits and vegetables play a vital role as food and drugs and are the main sources of antioxidant defences against degenerative diseases, such as brain dysfunctions, cardiovascular diseases, immune system deteriorations, and cancers, brought on by oxidative damage. Phyllanthus emblica is a significant herbal remedy used in conventional medicine to recover lost strength and power. In this research, the potential value of Phyllanthus emblica as a food and drug is researched. The total phenolic, total flavonoid, and total tannin contents as well as the nutritional value, vitamin C, vitamin E, and mineral contents of different organs of P. emblica were evaluated. The antioxidant and antimicrobial activities of extracts and fractions of different organs of P. emblica were determined. A total of eleven flavonoids, simple phenolic, tannin-related phenolic, and tannin molecules were isolated from a hydroalcoholic extract of the leaves and fruits. The structures were identified by spectroscopic data and comparison with the literature values as gallic acid (1), naringenin 7-O-(6″-O-galloyl)-β-D-glucopyranoside (2), 3,3′-di-O-methyl ellagic acid-4′-O-β-d-glucopyranoside (3), 1-O-galloyl glycerol (4), 1,6-di-O-galloyl-β-d-glucopyranoside (5), flavogallonic acid bislactone (6), corilagin (7), ethyl gallate (8), urolithin M5 (9), (E)-p-coumaroyl-1-O-β-d-glucopyranoside (10), and 1,2,4,6-tetra-O-galloyl-β-d-glucopyranoside (11). Among them, compounds 3 and 10 are first isolated from the plant. Molecular docking was performed to investigate the comparative interactions between positive controls (galantamine and donepezil) and selected compounds utilizing acetylcholinesterase (4EY7) as a target receptor. Results exhibited the potency of these compounds against the target receptor. In summary, P. emblica has a wealth of minerals, vitamins C and E, and polyphenolic phytochemicals that may work together to treat infectious disease, prevent and/or treat oxidative-damage-related illnesses including Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Three new [nilotinins M8‒M10 (1‒3)] and two known [tamarixinin A (4) and gemin D (5)] ellagitannins and seven simple phenolics [gallic acid (6), methyl gallate (7), 3,4-di-O-methylgallic acid (8), ellagic acid (9), 3-O-methylellagic acid (10), methyl ferulate 3-O-sulphate (11), and 7,4′-di-O-methylkaempferol (12)] were isolated from the halophytic plant Tamarix nilotica (Ehrenb.) Bunge (Tamaricaceae). Their structures were determined based on intensive spectroscopic studies and comparisons with reported data. Compounds 4, and 6–8 were evaluated for their cytotoxicity against lung adenocarcinoma cell line (A549) and anti-leishmanial activity against Leishmania major. Compounds 4, 6 and 7 showed promising cytotoxic properties against A549 (IC50 29 ± 2.3, 10.5 ± 0.7, and 20.7 ± 1.9 μg/mL), while compounds 4 and 7 showed higher growth-inhibitory effects against L. major promastigotes (IC50 40.5 ± 2.7 and 38.4 ± 2.5 μg/mL), as compared with the standards doxorubicin (IC50 0.42 µg/mL) and miltefosine (IC50 9.43 μg/mL), respectively. [ABSTRACT FROM AUTHOR]

An ellagitannin monomer, lythracin M (1), and a dimer, lythracin D (2), along with eight known monomers (3 − 10) were isolated from Lawsonia inermis (Lythraceae) leaves. Lythracin M (1) is a C -glycosidic ellagitannin with a flavogallonyl dilactone moiety that participates in the creation of a γ-lactone ring with the anomeric carbon of the glucose core. Lythracin D (2) was determined as an atropisomer of the reported lythcarin D. These newly discovered structures (1 and 2) were determined by intensive spectroscopic experiments and by comparing DFT-calculated 1H 1H coupling, 1H NMR chemical shifts, and ECD data with experimental values. The anti-acetylcholinesterase assay of the compounds 1 – 10 revealed that the C-1 ellagitannin epimers [casuarinin (7 ; IC 50 = 34 ± 2 nM) and stachyurin (8 ; IC 50 = 56 ± 3 nM)], and the new dimer (2 ; IC 50 = 61 ± 4 nM) possess enzyme inhibitory effects comparable to the reference drug (donepezil, IC 50 = 44 ± 3 nM). Molecular docking of compounds 1 – 10 with AChE identified the free galloyl moiety as an important pharmacophore in the anticholinesterase activity of tannins. [Display omitted] • Two new (1 and 2) and eight known ellagitannins (3 – 10) were isolated from leaves of L. inermis. • The stereo-structure of 1 was established based on DFT calculations and intensive spectroscopic studies. • The anti-AChE activity of 1 – 10 was evaluated experimentally and by using molecular docking. • The ellagitannins 2 , 7 , and 8 are promising anti-AChE. [ABSTRACT FROM AUTHOR]

Chromatographic separation of an aqueous acetone extract of the galls from Tamarix aphylla using gels resulted in isolation of an ellagitannin, phyllagallin M1 ( 13 ), a gallo-ellagitannin, phyllagallin D1 ( 14 ), and four gallotannins, phyllagallin M2 ( 15 ) and phyllagallins D2–D4 ( 16 – 18 ), in addition to four known ellagitannins and three phenolics of lower molecular weight structurally related to hydrolyzable tannins. The structures of the six new tannins were elucidated based on spectroscopic and chemical data. Among the phenolics, flavogallonic acid dilactone ( 8 ), which is presumed to be biogenetically produced by C–C oxidative coupling of an ellagic acid unit with a galloyl residue, shows an exceptional oxidative pattern of gallic acid residues in plants of the family Tamaricaceae. Although the ellagitannin tamarixellagic acid ( 4 ) was reported to be a constituent of the galls of T. aphylla , such compounds with anomalous location of the DHDG moiety at O-3 on the glucopyranose core have not been observed among the tannins of tamaricaceous plants. [ABSTRACT FROM AUTHOR]

Abstract: Shoot cultures of Tamarix tetrandra on Linsmaier–Skoog (LS) agar medium with 30gl−1 sucrose, 2.13mgl−1 indoleacetic acid and 2.25mgl−1 benzyl adenine produced ellagitannins found in intact plants of the Tamaricaceae. This was demonstrated by the isolation of 14 monomeric–tetrameric ellagitannins from the aq. Me2CO extract of the cultured tissues. This is the first report on the production of ellagitannin tetramers by plant tissue culture. The effects of light and certain medium constituents on tissue growth and ellagitannin production were examined. The contents of representative tannins of different types [i.e., tellimagrandin II (monomer), hirtellin A (linear GOG-type dimer), hirtellin B (hellinoyl-type dimer), hirtellin C (macrocyclic-type dimer), and hirtellin T1 (linear GOG-type trimer)] in the resultant tissues in response to these factors were estimated by HPLC, and the optimal condition for production of these tannins were established. Shoots cultured on LS hormone-free medium promoted root development, and regenerated plants could adapt to ordinary soil and climate. Acclimatized and intact T. tetrandra plants that were collected in November and May, respectively, demonstrated seasonal differences in individual ellagitannin contents. HPLC comparison of individual ellagitannin contents in different plant materials (i.e., leaves, stems, and roots) of intact T. tetrandra plants is also reported. The results are discussed with respect to cellular deposition and biosynthetic relationship of tannins. [Copyright &y& Elsevier]

Abstract: An ellagitannin monomer, nilotinin M1 (1), and three dimers, nilotinins D1 (2), D2 (3), and D3 (4), were isolated from leaves of Tamarix nilotica (Ehrenb.) Bunge. Structures were elucidated based on analysis of spectroscopic data and chemical correlations with known compounds. In addition, six known tannins, hirtellin A (5) (dimer), remurin A (6), remurin B (7), 1,3-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-β-d-glucose (8), gemin D (9), and hippomanin A (10) (monomers), were isolated for the first time from this plant species. The reported 13C NMR assignments of the dehydrodigalloyl moiety and glucose cores of 5 are revised, and the 13C NMR spectroscopic data for 6 and 7 are also reported for the first time. [Copyright &y& Elsevier]

Investigation on tannins having antitumor properties led to the isolation of two new C -glycosidic ellagitannins (1 and 2) along with seven known ellagitannins (3 – 9) and a related polyphenolic constituent (10) from Lawsonia inermis leaves. Our intensive HRESIMS, 1D and 2D NMR, and ECD spectroscopic studies of new tannins have shown that one (1) has a monomer structure of C -glycosidic tannin, and the other (2) has a dimeric structure of 2,3- O -hexahydroxydiphenoyl glucopyranose and a C -glycosidic tannin. Among the known compounds, one (3) is a C -glycosidic tannin that was isolated first of all from nature, five were C -glycosidic tannins, vescalagin (4), 1- O -methylvescalagin (5), castalagin (6), stachyurin (7), and casuarinin (8), and one was an O- glycosidic ellagitannin, tellimagrandin II (9). The remaining phenolic constituent from the leaves was identified as valoneic acid dilactone (10). The ellagitannins 1 , and 3 – 9 demonstrated noticeable cytotoxicity on human oral squamous cell carcinoma cell lines (HSC-2, HSC-4, and Ca9–22), and lower effects on human oral normal cells (HGF, HPC, and HPLF). Tellimagrandin II (9) had the highest tumor-specific cytotoxicity, and also cleaved poly (ADP-ribose) polymerase 1 in HSC-2 cells. These findings showed that L. inermis ellagitannins may be a candidate for the production of anti-oral cancer materials. [Display omitted] • Two new (1 and 2), a first isolated from nature (3), and six knowns (4 – 9) ellagitannins, and a related phenolic (10) were isolated from leaves of L. inermis. • The ellagitannins (1 , 3 – 9) exhibited higher cytotoxicity against human oral cancer cell lines (HSC-2, HSC-4, and Ca9–22) than against human normal oral cells (HGF, HPC, and HPLF). • Tellimagrandin II (9) induced cleavage of PARP1 in HSC-2 cells. [ABSTRACT FROM AUTHOR]