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Four previously undescribed glutamic acid derivatives, verticillamines A-D (1-4), together with six known compounds (5-10) were isolated from the bulbs of Fritillaria verticillate Willd. The structures of (1-10) were established on the basis of UV, IR, MS, 1D and 2D NMR, and the absolute configurations of compounds (1-4) were determined by calculated ECD methods. Among them, compounds (1-3) were rare 2-methyl-γ-lactam alkaloid derivatives. Moreover, both γ-lactam alkaloids (1-5) and pyrrolidine alkaloids (6-7) were discovered in Fritillaria for the first time. Compound 8 exhibited moderate cytotoxic activities against A2780 and HepG 2 cells, with IC 50 values of 11.7 ± 5.2 μM and 25.6 ± 2.8 μM., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Two new 13,14:14,15-disecopregnane-type C 21 steroidal glycosides, namely komarosides R (1) and S (2), along with four known compounds (3-6), were obtained from the 95% ethanol extract of the whole herbs of Cynanchum komarovii Al.Iljinski (Asclepiadaceae). The structures of new compounds were elucidated on the basis of 1D, 2D NMR spectroscopic data and acid hydrolysis. Compounds 1 and 2 showed potent inhibitory activities against human leukemia cell line (HL-60) with IC 50 values being 6.2 and 17.6 μM, respectively, compared to the positive control 5-fluorouracil (6.4 μM).

Investigation of the alkaloids from Peganum harmala seeds yielded two pairs of unique racemic pyrroloindole alkaloids, (±)-peganines A-B (1-2); two rare thiazole derivatives, peganumals A-B (3-4); six new β-carboline alkaloids, pegaharmines F-K (5-10); and 12 known analogues. Their structures, including stereochemistry, were elucidated through spectroscopic analyses, quantum chemistry calculations, and single-crystal X-ray diffraction. Notably, the incorporation of pyrrole and indole moieties in peganines A-B, thiazole fragments in peganumals A-B, and a C-1 α,β-unsaturated ester motif in pegaharmine F (5) are all rare, and their presence in the genus Peganum were demonstrated for the first time. All isolates were tested for antiproliferative activities against the HL-60, PC-3, and SGC-7901 cancer cell lines, and compounds 9, 11, 12, and 13 exhibited moderate cytotoxicity against HL-60 cancer cell lines with IC 50 values in the range of 4.36-9.25 μM.

In this study, we screened 17 medicinal plants for binding activity to G-quadruplex d(TTGGGTT)4 by (1)H NMR spectroscopy and found that the crude extract of Peganum harmala L. seeds showed the most potential binding activity. Subsequently, (1)H NMR- and bioassay-guided isolation of the extract of P. harmala L. was performed to obtain four pairs of partially racemized β-carboline alkaloids, pegaharmines A-D (1-4). Their structures and absolute configurations were determined by extensive NMR analyses, X-ray crystallography, ECD calculations, and CD exciton chirality approaches. Interestingly, pegaharmine D (4), which showed the strongest G-quadruplex interaction, exhibited significant cytotoxic activity against three cancer cell lines. This work contributed a practical strategy for the discovery of novel G-quadruplex ligands from natural products and provided potential insights for using β-carboline alkaloids as anticancer lead compounds specifically targeting G-quadruplexes.

Four quinolone alkaloids (1-4) and three indole alkaloids (20-22), together with 30 known alkaloids (5-19, 23-37), were isolated from the fruits of Euodia rutaecarpa. Their structures were established by spectroscopic analyses. The in vitro cytotoxic activities of these alkaloids against leukaemia HL-60 and prostate cancer PC-3 cell lines were evaluated., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Peganumine A (1), a new dimeric β-carboline alkaloid characterized by a unique 3,9-diazatetracyclo[6.5.2.0(1,9).0(3,8)]pentadec-2-one scaffold, was isolated from the seeds of Peganum harmala. The structure including the absolute configuration was determined by spectroscopic data, X-ray crystallography, ECD calculation, and CD exciton chirality approaches. Compound 1 showed moderate cytotoxic activity against MCF-7, PC-3, and HepG2 cells and selective effects on HL-60 cells with an IC50 value of 5.8 μM.

Five new 3,4-seco-lanostane-type triterpenoids, seco-coccinic acids G-K (1-5), and a known compound, seco-coccinic F, were isolated from the roots of Kadsura coccinea (Lem.) A. C. Sm. Their structures were elucidated by spectroscopic methods, including 2D-NMR and HR-MS techniques. The cell growth inhibitory effects of these compounds were assayed in human leukemia HL-60 cells, and it was found that 1, 5, and 6 showed antiproliferative effects with GI₅₀ values of 28.4, 15.2, and 16.6 µM, respectively., (Georg Thieme Verlag KG Stuttgart · New York.)

Two new phenylpropionic acid derivates, cerberic acids A (1) and B (2), were isolated from the bark of Cerbera manghas. Their structures were established on the basis of spectroscopic methods including IR, ESI-FT-ICR-MS, 1D and 2D NMR. Primary bioassays showed that compound 1 possessed weak cytotoxic activity against HepG2, MCF-7, and HeLa cell lines with IC(50) values of 44.7, 52.3, 48.7 μg/ml, respectively., (Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.)

Two new steroidal glycosides characterized with 2,6-dideoxypyranoses as component sugars have been isolated from roots of Cynanchum wallichii Wight. Their structure elucidation and cytotoxic activities against HL-60 and PC-3 cells are reported.

Two new triterpenoids, 2alpha-hydroxy-3beta-O-acetyllup-20(29)-en-28-oic acid (1) and 3- O-(4'- O-acetyl)-alpha- L-arabinopyranosyloleanolic acid ( 2), together with two known triterpenoids, betulinic acid ( 3) and messagenic acid ( 4) were isolated from the CHCl3 extract of Garcinia hanburyi resin. The structures were elucidated by analysis of the NMR spectroscopic data. The antiproliferative effects and the apoptosis induction abilities of compounds 1 and 2 were determined in four human leukemia cell lines. Compound 2 was more potent than compound 1 in inhibiting cell growth with IC50 values of 2.45, 2.69, 2.42, and 4.15 microM in HL-60, NB4, U937 and K562 cells, respectively.

Three new sterols, 3beta,16alpha-dihydroxy-5alpha,17beta-cholestan-21-carboxylic acid (1), 3beta-acetoxy-16alpha-hydroxy-5alpha,17beta-cholestan-21-carboxylic acid (2) and 3beta-(3-hydroxybutyroxy)-16alpha-hydroxy-5alpha,17beta-cholestan-21-carboxylic acid (3) were isolated from Selaginella tamariscina (Beauv.) Spring (Selaginellaceae). Their structures were elucidated based on NMR analyses. The growth inhibitory effects and differentiation induction abilities of compounds 1 - 3 were determined in human leukemia HL-60 cells. Compound 1 was more effective than compounds 2 and 3 in inhibiting cell growth, but compound 3 was more effective than compounds 1 and 2 in enhancing induction of all- trans-retinoic acid differentiation.