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Five new sesquiterpenoids, dictamtrinorguaianols E and F (1–2), and dictameudesmnosides F, G, and H (3–5), along with seven known sesquiterpenoids (6–12) were isolated from Dictamnus dasycarpus Turcz. The structures of all new compounds were characterized by spectroscopic methods, including UV, IR, HR-ESI-MS, and 1D and 2D NMR. The In-vitro anti-proliferative activities of all the compounds against two human cancer cell lines (SW982 and A549) were evaluated by CCK-8 assay. Compounds 1 and 4 showed medium anti-proliferative activity against SW982 cells, with IC 50 values of 3.49 ± 0.10 and 6.42 ± 1.23 μM, respectively. Additionally, compounds 2 , 7 , and 8 exhibited medium anti-proliferative activity against A549 cells, with IC50 values ranging from 0.80 ± 0.05 to 6.60 ± 0.46 μM. [Display omitted] [ABSTRACT FROM AUTHOR]

Nine polyacetylenes, including five new compounds named sadivaethynes E -I (1 – 5), were isolated from the roots of Saposhnikovia divaricata. Structural elucidation of compounds 1 – 5 was established by extensive spectroscopic analysis, quantum chemical calculations and DP4+ probability analysis. Among them, the absolute configuration of compound 1 – 2 , 4 – 5 was unambiguous determined by ECD. Also, all compounds were evaluated for cytotoxicity against two human cancer cell lines (A549, HEPG2) in vitro, compound 9 showed moderate inhibitory effect with an IC 50 value of 11.66 μM against HEPG2. [Display omitted] • Five undescribed compounds were isolated from the roots of Saposhnikovia divaricata. • The structures were characterized chemically by NMR, quantum chemical calculations and CD data analysis. • Compound 9 showed moderate inhibitory effect with an IC 50 value of 11.66 μM against HEPG2. [ABSTRACT FROM AUTHOR]

The new natural products reported in 2019 in peer-reviewed articles in journals with good reputations were reviewed and analyzed. The advances made by Asian research groups in the field of natural products chemistry in 2019 were summarized. Compounds with unique structural features and/or promising bioactivities originating from Asian natural sources were discussed based on their structural classification. [ABSTRACT FROM AUTHOR]

Phytochemical investigation on the stems of Schisandra glaucescens resulted into the isolation of three new lanostane triterpenoids, 12-hydroxyschiglausin B (1), 12-hydroxykadsuphilactone B (2), and 20R-hydroxyschinalactone C (3). Structural elucidation of all the compounds was accomplished by spectral methods. The isolated compounds were tested in vitro for cytotoxic activities. As a result, triterpenoids 1 and 2 showed cytotoxic activities for all six tested tumor cell lines with IC50 values less than 15 μM. [ABSTRACT FROM AUTHOR]

Six new polyoxygenated seco-cyclohexenes, artahongkongenes A–F ( 1–6 ), together with six known analogues ( 7–12 ) were isolated from the stems and leaves of Artabotrys hongkongensis . Their structures were elucidated by extensive spectroscopic methods. All new compounds were evaluated for their cytotoxicities against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 in vitro . New seco-cyclohexenes 1–6 showed significant inhibitory effects against various human cancer cell lines with IC 50 values ranging from 0.26 to 16.58 μM. [ABSTRACT FROM AUTHOR]

Eight new iridoids (1–8) and an ionone glucoside (9), together with 31 known compounds (10–40), were isolated from the whole plants of Rehmannia henryi. The structures of these compounds were elucidated on the basis of their spectroscopic data and chemical evidence. [ABSTRACT FROM AUTHOR]

The root of Croton crassifolius has been used as a traditional Chinese medicine (TCM), called Radix Croton Crassifolius, and commonly known as "Ji Gu Xiang" in Chinese. Its medicinal value has been recorded in several medical books or handbooks, such as "Sheng Cao Yao Xing Bei Yao", "Ben Cao Qiu Yuan" and "Zhong Hua Ben Cao". It has been traditional employed for treating sore throat, stomach-ache, rheumatism and cancer. At present, there are limited studies on the evaluation of low-polarity extracts of roots in C. crassifolius. Consequently, the aim of this study was to evaluate the antitumor effect of the low-polarity extract of C. crassifolius root. Extracts were obtained by supercritical fluid extraction. The extracts were tested for antitumor effects in vitro on several cancer cell lines. A CCK-8 kit was used for further analysis of cell viability. A flow cytometer and propidium iodide staining were used to evaluate the cell cycle and apoptosis. Hoechst staining, JC-1 staining and the fluorescence probe DCFH-DA were used to evaluate apoptotic cells. Molecular mechanisms of action were analyzed by quantitative RT‒PCR and Western blotting. Immunohistochemistry was used for the evaluation of xenograft tumors in male BALB/c mice. Finally, molecular docking was employed to predict the bond between the desired bioactive compound and molecular targets. Eleven diterpenoids were isolated from low-polarity C. crassifolius root extracts. Among the compounds, chettaphanin II showed the strongest activity (IC 50 = 8.58 μM) against A549 cells. Evaluation of cell viability and the cell cycle showed that Chettaphanin II reduced A549 cell proliferation and induced G2/M-phase arrest. Chttaphanin II significantly induced apoptosis in A549 cells, which was related to the level of apoptosis-related proteins. The growth of tumor tissue was significantly inhibited by chettaphanin II in experiments performed on naked mice. The antitumor mechanism of chettaphanin II is that it can obstruct the mTOR/PI3K/Akt signaling pathway in A549 cells. Molecular docking established that chettaphanin II could bind to the active sites of Bcl-2 and Bax. Taken together, the natural diterpenoid chettaphanin II was identified as the major antitumor active component, and its potential for developing anticancer therapies was demonstrated for the first time by antiproliferation evaluation in vitro and in vivo. [Display omitted] • Eleven diterpenoids were obtained from the SFE extract of C. crassifolius roots. • Chettaphanin II showed the strongest antitumor activity against A549 cells. • Chettaphanin II inhibited A549 cell proliferation and arrested cells in G2/M-phase. • Chettaphanin II induced A549 cell apoptosis by inhibiting PI3K/AKT/mTOR pathway. • Chettaphanin II significantly inhibited the growth of tumor tissue in nude mice. [ABSTRACT FROM AUTHOR]

Seven new iridals ( 1 – 7 ), designated as iritectols C–F, 22-epiiritectol D, 22-epiiritectol E, 22-epiiritectol F together with three known analogues were isolated from the rhizomes of Iris tectorum . Among them, compounds 2 and 3 , 4 and 5 , and 6 and 7 were found to be three pairs of C-22 epimers, some of which were separated by chiral column chromatography. This is the first report on the occurrence of epimers of monocyclic iridals. Their structures were elucidated on the basis of extensive spectroscopic analysis. The isolates were evaluated for their cytotoxic activities against five human tumor cell lines. Compound 1 but not others exhibited moderate cytotoxic activities, with IC 50 values ranging from 4.1 to 9.8 μM. The structure–activity relationship of the tested compounds was briefly discussed. [ABSTRACT FROM AUTHOR]

Two new triterpenoid saponins, oleiferoside N and oleiferoside O, were isolated from the EtOH extract from the roots ofCamellia oleiferaC. Abel. Their structures were elucidated as 16α-acetoxy-21β,22α-O-diangeloyloxy-23,28-dihydroxyolean-12-ene 3β-O-β-d-xylopyranosyl-(1 → 3)-α-l-arabinopyranosyl-(1 → 3)-β-d-glucuronopyranoside (1), 16α-acetoxy-21β-O-angeloyloxy-23,28-dihydroxy-22α-O-(2-methylbutanoyloxy)olean-12-ene 3β-O-β-d-xylopyranosyl-(1 → 3)-α-l-arabinopyranosyl-(1 → 3)-β-d-glucuronopyranoside (2), on the basis of spectroscopic analyses (IR, ESI-MS, HR-ESI-MS, 1D and 2D NMR) and acid hydrolysis. Both were characterized to be oleanane-type saponins with sugar moieties linked to C-3 of the aglycone. Cytotoxic activities of two saponins were evaluated against four human tumor cell lines (A549, B16, BEL-7402, and MCF-7) by using the MTTin vitroassay. Compounds1and2showed moderate cytotoxic activities toward the tested cell lines. [ABSTRACT FROM PUBLISHER]

Five new phorbol esters, (four phorbol diesters, 1 – 4 , and one 4-deoxy-4α-phorbol diester, 5 ), as well as four known phorbol esters analogues ( 6 – 9 ) were isolated and identified from the branches and leaves of Croton tiglium . Their structures were elucidated mainly by extensive NMR spectroscopic, and mass spectrometric analysis. Among them, compound ( 1 ) was the first example of a naturally occurring phorbol ester with the 20-aldehyde group. Compounds 2 – 5 , and 7 – 9 showed potent cytotoxicity against the K562, A549, DU145, H1975, MCF-7, U937, SGC-7901, HL60, Hela, and MOLT-4 cell lines, with IC 50 values ranging from 1.0 to 43 μM, while none of the compounds exhibited cytotoxic effects on normal human cell lines 293T and LX-2, respectively. In addition, compound 3 exhibited moderate COX-1 and COX-2 inhibition, with IC 50 values of 0.14 and 8.5 μM, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Three new copper(II) complexes of 5-pyridin-2-yl-[1,3]dioxolo[4,5-g]isoquinoline (PYP), i.e. [Cu2(PYP)2Cl4] (1), [Cu4(PYP)4(ClO4)2(H2O)2](ClO4)2·2H2O (2), and [Cu2(PYP)2Cl4] n (3), were synthesized and fully characterized. In comparison to free PYP, complexes 1–3 exhibited enhanced cytotoxicity against tested human tumor cell lines BEL-7404, SK-OV-3, A549, A375, MGC-803 and NCI-H460, with IC50 values ranging from 0.31 to 30.76 μM. Complexes 1–3 exhibited lower cytotoxicity to HL-7702 than them to cancer cells. Complex 1 induced apoptotic death of BEL-7404, which involved mitochondria in the process. Caspase-3 activation assay indicated that 1 could be an efficient activator of caspase-3. DNA binding studies by UV–vis, DNA-melting, competitive binding, CD, viscosity measurement and agarose gel electrophoresis, revealed that intercalation might be the most likely binding mode of 1 with DNA. [Copyright &y& Elsevier]

Nuclear factor erythroid 2-related factor 2 (Nrf2) is involved in tumor drug resistance, but its role in imatinib resistance of chronic myeloid leukemia (CML) remains elusive. We aimed to investigate the effects of Nrf2 on drug sensitivity, thioredoxin reductase (TrxR) expression, reactive oxygen species (ROS) production, and apoptosis induction in imatinib-resistant CML K562/G01 cells and explored their potential mechanisms. Stable K562/G01 cells with knockdown of Nrf2 were established by infection of siRNA-expressing lentivirus. The mRNA and protein expression levels of Nrf2 and TrxR were determined by real-time quantitative polymerase chain reaction and western blot, respectively. ROS generation and apoptosis were assayed by flow cytometry, while drug sensitivity was measured by the Cell Counting Kit-8 assay. Imatinib-resistant K562/G01 cells had higher levels of Nrf2 expression than the parental K562 cells at both mRNA and protein levels. Expression levels of Nrf2 and TrxR were positively correlated in K562/G01 cells. Knockdown of Nrf2 in K562/G01 cells enhanced the intracellular ROS level, suppressed cell proliferation, and increased apoptosis in response to imatinib treatments. Nrf2 expression contributes to the imatinib resistance of K562/G01 cells and is positively correlated with TrxR expression. Targeted inhibition of the Nrf2-TrxR axis represents a potential therapeutic approach for imatinib-resistant CML. [ABSTRACT FROM AUTHOR]

Graphical abstract Pt(II) complex 1- induced mitochondrial dysfunction could be an valuable target for the development of new anticancer drugs. Abstract Two new Pt(II) and Ru(II) complexes, [Pt(BFCY)Cl 2 ] (1) and [RuCl 2 (BMCY)(DMSO)] (2) with 3-(1H-benzoimidazol-2-yl)-8-fluoro-chromen-2-ylideneamine (BFCY) and 3-(1H-benzoimidazol-2-yl)-8-methyl-chromen-2-ylideneamine (BMCY), were synthesized. The BFCY Pt(II) complex 1 adopted an approximately four-coordinated square planar geometry, while BMCY complex 2 formed a distorted octahedral geometry. Among the seven selected human cancer cell lines, the two new Pt(II) and Ru(II) complexes 1 and 2 exhibited more potent activities against cisplatin-resistant SK-OV-3/DDP tumor cells (IC 50 = 2.08 ± 1.04 μM and 18.06 ± 0.36 μM, respectively), compared with the free BFCY and BMCY ligands as well as cisplatin. In addition, the BFCY Pt(II) complex 1 could induce cell cycle arrest in S phase and regulate the S-phase cell cycle-related proteins. Remarkably, the BFCY Pt(II) complex 1 also induced mitochondrial dysfunction. [ABSTRACT FROM AUTHOR]

Camellia oleifera C. Abel has been widely cultivated in China, and a group of bioactive constituents such as triterpeniod saponin have been isolated from C. oleifera C. Abel. In the current study, a new triterpeniod saponin was isolated from the EtOH extract of the roots of C. oleifera C. Abel, named as oleiferoside W, and the cytotoxic properties of oleiferoside W were evaluated in non-small cell lung cancer A549 cells. At the same time the inducing apoptosis, the depolarization of mitochondrial membrane potential (Δψ), the up-regulation of related pro-apoptotic proteins, such as cleaved-PARP, cleaved-caspase-3, and the down-regulation of anti-apoptotic marker Bcl-2/Bax were measured on oleiferoside W. Furthermore, the function, inducing the generation of reactive oxygen species (ROS) and apoptosis, of oleiferoside W could be reversed by N-acetylcysteine (NAC). In conclusion, our findings showed that oleiferoside W induced apoptosis involving mitochondrial pathway and increasing intracellular ROS production in the A549 cells, suggesting that oleiferoside W may have the possibility to be a useful anticancer agent for therapy in lung cancer. [ABSTRACT FROM AUTHOR]

Purpose: The mechanisms underlying the oncogenic properties of WW domain binding protein 2 (WBP2) in breast cancer have not been fully understood. In this study, we explored the role of WBP2 in cell cycle regulation in ER+ breast cancer cells and how it is regulated in the cancer cells.Methods: The association between WBP2 expression and prognosis in ER+ breast cancer was assessed by data mining in Breast Cancer Gene-Expression Miner v4.0. Cell cycle was assessed by PI staining and flow cytometry. EdU staining was applied to visualize cells in S phase. The binding between miR-206 and WBP2 were verified by dual luciferase assay. CCK-8 assay and flow cytometric analysis were applied to assess the functional role of WBP2 and miR-206 in the cancer cells.Results: High WBP2 expression correlates with higher risk of any events (AE) and metastatic relapse (MR) and also indicates shorter AE-free survival and MR-free survival in ER+ breast cancer patients. In both MCF-7 and BT474 cells, WBP can influence the expression of G1/S-related cell cycle proteins, including p21, CDK4, and cyclin D1. In addition, WBP2 overexpression resulted in facilitated G1/S transition, while WBP2 knockdown impaired the transition. The 3'UTR of WBP2 has a conserved miR-206 binding site. Functionally, miR-206 knockdown decreased tamoxifen sensitivity in tamoxifen-sensitive (TamS) MCF-7 cells, while miR-206 overexpression and WBP2 knockdown enhanced the sensitivity in tamoxifen-resistant (TamR) MCF-7 cells.Conclusion: Based on these findings, we infer that the miR-206/WBP2 axis can modulate tamoxifen sensitivity via regulating G1/S progression in ER+ breast cancer. [ABSTRACT FROM AUTHOR]

Abstract: A series of novel 2′,3′-diethanethio-2′,3′,5′-trideoxy-5′-triazoloribonucleosides was synthesized in excellent yields and their antitumor activity was evaluated. These nucleoside analogues with aromatic substituted triazole rings showed significantly improved activity towards a broad range of tumor cell lines and those without arene substitutes were inactive. [Copyright &y& Elsevier]