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The chemical constituents of the roots, seeds, and bark of Azadirachta indica var. siamensis were investigated, leading to the isolation of six tricyclic diterpenoids and five limonoids, including two new compounds (2, 5). The structures were elucidated based on NMR spectroscopic techniques, mass spectrometry and single-crystal X-ray diffraction as well as comparison with the literature. Moreover, the cytotoxicity activities of the isolates were evaluated. The results indicated that the compounds 1-3, 5-9 exhibited cytotoxicities against one or more cancer cell lines tested, with IC 50 values in the range of 1.7-88.1 μM. The mechanism of action studies indicated that the most active compound, compound 5, could induce the apoptosis of AZ521 cells. Furthermore, the Western blot analysis showed that compound 5 could reduce the expression levels of procaspases-3, -8, -9 and promote the expression of Bid and AIF., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Five oleanane-type triterpene glycosides including three new ones, proceraosides E-G (1-3), were isolated from a MeOH-soluble extract of Albizia procera bark. The structures of 1-3 were determined by use of NMR spectra, HRESIMS, and chemical methods. Compounds 1-5 exhibited inhibitory activities against the proliferation of the A549, SKBR3, AZ521, and HL60 human cancer cell lines (IC 50 0.28-1.8 μM). Additionally, the apoptosis-inducing activity of compound 2 was evaluated by Hoechst 33342 staining and flow cytometry, while the effects of 2 on the activation of caspases-9, -8, and -3 in HL60 cells were revealed by Western blot analysis.

Three hiherto unknown phenylpropanoid compounds, namely (7S,8R)-1-(1-ethoxy-2-hydroxypropyl)-2-methoxy-3,4-(methylenedioxy)benzene (1), (7S,8S)-1-(1-ethoxy-2-hydroxypropyl)-2-methoxy-3,4-(methylenedioxy)benzene (2), and (7S,8R)-1-(1-methoxy-2-hydroxypropyl)-2-methoxy-3,4-(methylenedioxy)benzene (3), along with 12 known compounds (4 - 15) were obtained from the extract of whole plant of Chloranthus anhuiensis. Among them, 7 and 13 were obtained from nature for the first time. The structures of these natural compounds were characterized by extensive spectroscopic analysis and calculated electronic circular dichroism (ECD) data. Furthermore, their cytotoxic and neuroprotective activities were evaluated using MDA-MB-231, 4T1, HepG2, and PC12 cell lines. Compounds 8 and 13 exhibited moderate cytotoxic activities against MDA-MB-231 cell line with the IC 50 values of 39.7 and 25.8 μm, respectively. And all the isolated compounds have no neuroprotective activities., (© 2018 Wiley-VHCA AG, Zurich, Switzerland.)

There is a growing interest in the exploitation of agricultural byproducts. This study explored the potential beneficial health effects from the main biowaste, tea seed pomace of Camellia oleifera Abel (Theaceae), produced when tea seed is processed. Eighteen compounds were isolated from the 70% EtOH extract of the seed cake of C. oleifera. Their structures were determined by ESI-MS, 1 H- and 13 C-NMR together with literature data. All fractions and compounds were evaluated for the antioxidant and melanogenesis inhibitory activities. As the result, AcOEt fraction has the best in vitro antioxidant and antimelanogenesis activities, compounds 7 - 12 and 15 showed remarkable antioxidant activity, compounds 4, 6, 8, and 15 - 17 exhibited superior inhibitory activities against melanogenesis. Furthermore, tyrosinase inhibitory activity assay suggested that compound 8 could suppress melanogenesis by inhibiting the expression of tyrosinase., (© 2018 Wiley-VHCA AG, Zurich, Switzerland.)

Seven phenolic compounds, 1 - 7, including a new organic acid gallate, mucic acid 1-ethyl 6-methyl ester 2-O-gallate (7), were isolated from the MeOH extract of the fruits of Phyllanthus emblica L. (Euphorbiaceae). The structures were elucidated on the basis of extensive spectroscopic analysis and comparison with literature data. Upon evaluated for their antioxidant abilities by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. The inhibitory activities against melanogenesis in B16 melanoma cells induced by α-MSH, as well as cytotoxic activities against four human cancer cell lines were also evaluated. All phenolic compounds, 1 - 7, exhibited potent antioxidant abilities (DPPH: IC 50 5.6 - 12.9 μm; ABTS: 0.87 - 8.43 μm Trolox/μm; FRAP: 1.01 - 5.79 μm Fe 2+ /μm, respectively). Besides, 5 - 7, also exhibited moderate inhibitory activities against melanogenesis (80.7 - 86.8% melanin content), even with no or low toxicity to the cells (93.5 - 101.6% cell viability) at a high concentration of 100 μm. Compounds 1 - 3 exhibited cytotoxic activity against one or more cell lines (IC 50 13.9 - 68.4%), and compound 1 with high tumor selectivity for A549 (SI 3.2)., (© 2017 Wiley-VHCA AG, Zurich, Switzerland.)

Phytochemical investigation on the stems of Picrasma quassioides led to the isolation of a novel compound, picraquassin A (1), with an unprecedented 21,24-cycloapotirucallane skeleton, and four new apotirucallane-type triterpenoids (2-5), together with 15 new tirucallane-type triterpenoids (6-20) and 10 known tirucallane-type triterpenoids (21-30). To our knowledge, this is the first report demonstrating the presence of apotirucallane-type triterpenoids in the genus Picrasma. The structures of the new compounds were determined based on spectroscopic data interpretation. Cytotoxicities of the isolated compounds were evaluated using three human cancer cell lines, MKN-28, A-549, and MCF-7. Compound 2 exhibited the most potent activity against MKN-28 cells with an IC50 value of 2.5 μM. Flow cytometry and Western blot analysis revealed that 2 induces the apoptosis of MKN-28 cells via activating caspase-3/-9, while increasing Bax and Bad and decreasing Bcl-2 expression levels.

Phytochemical investigation on the stem bark of Toona sinensis was carried out by various chromatographic techniques resulting in the isolation and elucidation of two novel tirucallane triterpenoids, named (20S)-3-oxo-tirucalla-25-nor-7-en-24-oic acid (1) and (20S)-5α,8α-epidioxy-3-oxo-24-nor-6.9(11)-dien-23-oic acid (2), along with fifteen known triterpenoids (3-17), their structures were determined by extensive spectroscopic methods, including 1D-, 2D-NMR and HR-ESI-MS experiments. Compound 2 is uncommon in nature, which possesses a peroxide bridge cross C-5 and C-8 in the triterpenoid skeleton. All isolated compounds were evaluated for cytotoxicity against five human tumor cell lines (A-549, Hela, HepG2, SGC-7901 and SW-480), among them, compound 17 displayed strongest cytotoxic activity against A-549 cells and the results indicated that its cytotoxicity against A-549 cells was mediated by the intrinsic mitochondrial apoptotic pathway. In addition, ROS production-inhibitory activities were also evaluated, but none of them was active., (Copyright © 2016 Elsevier B.V. All rights reserved.)

To synthesize a series of 3-, 4-, and/or 11-trihydroxy modified bergenin derivatives and evaluated their cytotoxic activity in vitro. The phenolic hydroxyl groups of bergenin were protected by benzyl groups with benzyl bromide. Treatment of dibenzyl bergenin with the corresponding acid in the presence of EDC·HCl and DMAP in CH2Cl2, followed by hydrogenation over Pd/C catalysts, afforded derivatives of bergenin esters. All of the target compounds were identified by IR, MS, and (1)H NMR. Twenty-six novel and three known derivatives of bergenin esters were synthesized. Their cytotoxicity values were evaluated by the MTT assay on the inhibition of DU-145 and BGC-823 cells in vitro. Several triply-substituted (3a, 4a, 5a, 6a, 7a) and doubly-substituted (8b, 9b) bergenin derivatives exhibited higher cytotoxic activity than bergenin. The result showed that the size of substituents and the lipophilicity of the bergenin esters displayed an important role on their cytotoxic activity., (Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.)

Gamboge, the resin of Garcinia hanburyi has had a long history of use as the traditional dye as well as a complementary and alternative medicine. The antitumor activities of gamboge have been well demonstrated by inhibiting the growth and progression of cancer cells both in vitro and in vivo. In order to further clarify the mode of action of gamboge, there are three key questions needed to be answered, including what's in gamboge? How do the chemical components from gamboge work on cancer cells? How do biological systems work on the chemical components from gamboge after administration? In this review, we summarize the explorations of the answers toward these questions according to the recent progress in both of chemistry and biology research of gamboge. In addition, the implication in the future research and discovery of the caged G. xanthones as anticancer agents is also discussed.