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• The Agavaceae species extracts had promising cytotoxicity against some cancer cells. • Some fractions from P. tuberosa, Y. filamentosa and F. Watsoniana had strong cytotoxicity. • Cytotoxicity shown by extracts may be related to steroidal saponins present. Among the plants which are determined to be a promising source of anticarcenogenic agents are members of Agavaceae family which are common in tropical and subtropical regions such as Egypt. In this study, cytotoxic activity were assessed for the methanolic extracts and fractions from five members of Agavaceae family: Sansevieria cylindrica Bojer., Polianthes tuberosa L., Sansevieria trifasciata Prain., Yucca filamentosa L. and Furcraea watsoniana Hort. against MCF-7 (breast), HepG-2 (hepatoma), and Caco-2 (colon) cancer cell lines by MTT method. The n -hexane fraction of P. tuberosa leaves extract demonstrated strong cytotoxic potential against all three cancer cell lines (CC 50 <20 µg/ml). The ethyl acetate fractions of Y. filamentosa and F. watsoniana leaves significantly inhibited proliferation of hepatocellular HepG-2 (CC 50 = 6.21 µg/ml and 19.07 µg/ml, respectively) and intestinal epithelium Caco-2 carcinoma cells (CC 50 = 18.86 µg/ml and 23.25 µg/ml, respectively). Presumably, the cytotoxic activity exhibited by n -hexane fraction of P. tuberosa , ethyl acetate fractions of Y. filamentosa and F. watsoniana may be related to the steroidal saponins that are present in these samples. [ABSTRACT FROM AUTHOR]

The methanolic extract and its sub-extracts (viz , n –hexane, DCM, EtOAc and MeOH) of the soft coral Sarcophyton acutum were evaluated as anti- Leishmania major and as anticancer (against the HepG2, MCF-7, and A549 cell lines) using the MTT assay. Six polyhydroxy sterols (1–6) were isolated from the most active cytotoxic and anti-leishmanial EtOAc-soluble fraction. Their structures were established as two new polyhydroxy sterols, acutumosterols A (1) and B (2), and four known structural analogues (3 – 6) by intensive spectroscopic analyses, and by comparison with data of related compounds. Compound 4 exerted noticeable cytotoxicity against HepG2 cell line (IC 50 17.2 ± 1.5 μg/mL), while the other pure isolates showed weak to moderate cytotoxicity (24.8 ± 2.8–57.2 ± 5.2). The results were discussed in relation to the structural features of these closely related sterols. Unlabelled Image • The anti- Leishmania major and cytotoxic activities (against HepG2, MCF-7, and A549 cell lines) of the Red Sea soft coral Sarcophyton acutum were evaluated. • Two new, acutumosterols A (1) and B (2), and four known (3 – 6) polyhydroxy sterols were isolated from the most active ethyl acetate fraction. • Cytotoxicity and anti- L. major activities of the pure isolates (1 – 6) were evaluated. [ABSTRACT FROM AUTHOR]

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., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Four flavanolignans, ceibapentains A (1) and B (2) and cinchonains Ia (3) and Ib (4), were isolated for the first time from an ethyl acetate extract of Ceiba pentandra (L) (Bombacaceae) aerial parts. The ceibapentains A (1) and B (2) are new compounds and their structures, including the absolute configurations, were determined by HRESIMS, 1D and 2D NMR, and electronic circular dichroism analyses, then compared with reported data. Compounds 1-4 were tested for their anti-Alzheimer's activity via an assessment of their inhibitory effect on amyloid β42 aggregation using a thioflavin T assay. The results revealed that cinchonain Ia (3) showed a higher inhibitory effect (91%) than the standard curcumin (70%). Compounds 1, 2, and 4 exhibited moderate activity, with inhibition ratios of 43%, 47%, and 58%, respectively. A molecular docking study on the binding mode of 3 and curcumin with an amyloid β1-40 peptide fibril structure indicated a high affinity of cinchonain 1a (3) towards amyloid β1-40 peptide, in agreement with the experimental results., Competing Interests: Declaration of Competing Interest The authors publicize no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Partially unacylated new oligomeric hydrolyzable tannins, nilotinin T2 (1, trimer) and nilotinin Q1 (2, tetramer), together with four known trimers, nilotinin T1 (3) and hirtellins T1-T3 (4-6), and a dimer, tamarixinin B (7), were isolated from the aqueous acetone extracts of leaves of Tamarix nilotica. Among them, the new trimer 1 and the known trimers 4 and 6, in addition to the partially unacylated new trimer nilotinin T3 (8), the known dimers nilotinin D3 (9) and tamarixinin C (10), and the monomer tellimagrandin I (11), were isolated from the cultured shoots of Tamarix tetrandra. The structures of the new hydrolyzable tannins were established by chromatographic analyses and extensive 1D and 2D NMR, HRESI-TOFMS, and ECD spectroscopic experiments. Among the new oligomeric tannins, the particular unacylated position of a glucose core is attributed to a possible biosynthetic route. Isolation of the same oligomeric tannins from cultured shoots of T. tetrandra emphasizes the unique biogenetic ability of the obtained cultures on production of the structurally and biologically characteristic tamaricaceous tannins commonly produced by the intact Tamarix plants. Additionally, tannins obtained in the present study together with gemin D (12) and 1,3-di-O-galloyl-4,6-O-(aS)-hexahydroxydiphenoyl-β-d-glucose (13), from our previous investigation of the leaves of T. nilotica, exhibited variable tumor-specific cytotoxic effects. The ellagitannin trimers 4, 6, and 8 and the dimer 9 exerted predominant tumor-selective cytotoxic effects with high specificity toward human promyelocytic leukemia cells.

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.

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.