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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 1 H 1 H coupling, 1 H 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., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mohamed A. A. Orabi reports financial support was provided by Najran University. Mohamed A. A. Orabi reports a relationship with Najran University that includes: employment., (Copyright © 2022 Elsevier B.V. All rights reserved.)

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.)

Acetylcholinesterase (AChE) inhibitor and telomerase reverse transcriptase (TERT) potentiator phytochemicals are highly targeted as anti-Alzheimerꞌs disease and as an anti-ageing process. A phytochemical study of Thunbergia erecta aerial parts resulted in the isolation of ten compounds (1-10). Their structures were identified based on spectral data and comparison with literature values. The activity of our pure isolates on AChE and TERT enzymes by documented in vitro assay methods were evaluated. The results indicated that apigenin (2), vanillic acid (4), and acacetin-7-O-β-D-glucoside (7) exhibited potent inhibition of AChE (IC 50 37.33, 30.80 and 49.57 ng/mL, respectively), compared to the standard drug donepezil (IC 50 31.25 ng/mL). In the TERT enzyme assay, compound 7 triggered a 1.66‑fold increase in telomerase activity at the concentration of 2.85 ng/ml. This is the first study that demonstrates that compound 7 isolated from T. erecta can lead to such telomerase activity relative to control cells. Virtual screening studies including docking, rapid overlay chemical structure (ROCS), and calculated structure-property relationships (SPR) were implemented in this work. Molecular docking studies supported the binding of compounds 2, 4, and 7 through hydrogen bonds (HBs) formation to essential amino acid residues namely ARG:24 A, SER:347 A, LYS:51 A, PHE:346 A, and GLY:345 A of acetylcholinesterase. ROCS and SPR analyses realized compound 2 as a possible treatment of Alzheimer's disease and as a lead compound for drug development process through applying semisynthetic modifications., (Copyright © 2021 Elsevier Inc. All rights reserved.)

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., (Copyright © 2020 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.)