Two new catechins from Zijuan green tea enhance the fitness and lifespan of Caenorhabditis elegans via insulin-like signaling pathways.

Green tea polyphenols show positive effects on human health and longevity. However, knowledge of the antiaging properties of green tea is limited to the major catechin epigallocatechin gallate (EGCG). The search for new ingredients in tea with strong antiaging activity deserves further study. Here we isolated and identified two new catechins from Zijuan green tea, named zijuanin E (1) and zijuanin F (2). Their structures were identified by extensive high-resolution mass spectroscopy (HR-MS), nuclear magnetic resonance (NMR), ultraviolet-vis (UV), infrared (IR) and circular dichroism (CD) spectroscopic analyses, and their 13C NMR and CD data were calculated. We used the nematode Caenorhabditis elegans (C. elegans) to analyze the health benefits and longevity effects of 1 and 2. Compounds 1 and 2 (100 µM) remarkably prolonged the lifespan of C. elegans by 67.2% and 56.0%, respectively, delaying the age-related decline of phenotypes, enhancing stress resistance, and reducing ROS and lipid accumulation. Furthermore, 1 and 2 did not affect the lifespan of daf-16, daf-2, sir-2.1, and skn-1 mutant worms, suggesting that they might work via the insulin/IGF and SKN-1/Nrf2 signaling pathways. Meanwhile, 1 and 2 also exhibited strong antioxidant activity in vitro. Surface plasmon resonance (SPR) evidence suggests that zijuanins E and F have strong human serum albumin (HSA) binding ability. Together, zijuanins E and F represent a new valuable class of tea components that promote healthspan and could be developed as potential dietary therapies against aging.

Chemical constituents from plant endophytic fungus Alternaria alternata.

Five new natural compounds (1-5) along with four known ones, involving dibenzo-α-pyrone derivatives, a benzo-γ-pyrone derivative and an amide-type compound were obtained from Alternaria alternata, an endophyte isolated from Paeonia lactiflora. The structures of these isolates were elucidated by intensive analysis of spectroscopic data including NMR, HRMS (ESI and EI), UV and IR spectra. Compounds (1-4) were evaluated for their cytotoxicities against five selected human tumourtumour cell lines (A-549, MDA-MB-231, MCF-7, KB and KB-VIN), and compound 3 exhibited activities against MDA-MB-231and MCF-7 with IC50 values of 20.1 µM and 32.2 µM.

One new benzophenone and one new 1,3-diphenylpropane from the fibrous roots of Anemarrhena asphodeloides Bge. and their cytotoxicity.

One new benzophenone (1) and one new 1,3-diphenylpropane (2) were obtained from the fibrous roots of Anemarrhena asphodeloides Bge. Their structures were determined by comprehensive 1D, 2D NMR and HRESIMS data. By comparing the calculated ECD curves and OR with the experimental data the absolute configurations were determined. The antitumor activity of all isolates was evaluated against two human hepatoma carcinoma cells (HepG2 and Hep3B) in vitro. The results demonstrated that compound 1 and 2 showed potent cytotoxicity against HepG2 and Hep3B cells.

Design, Synthesis, and Biological Evaluation of Novel Biotinylated Podophyllotoxin Derivatives as Potential Antitumor Agents.

Podophyllotoxin has long been used as an active substance for cytotoxic activity. Fourteen novel biotinylated podophyllotoxin derivatives were designed, synthesized, and evaluated for cytotoxic activity for this study. The synthesized compounds were evaluated for cytotoxic activity in the following human cancer cell lines, SW480, MCF-7, A-549, SMMC-7721, and HL-60 by MTT assay. Most of them exhibited potent cytotoxic effects and compound 15 showed the highest cytotoxic activity among the five cancer cell lines tested, having its IC50 values in the range of 0.13 to 0.84 µM. Apoptosis analysis revealed that compound 15 caused obvious induction of cell apoptosis. Compound 15 significantly down-regulated the expression level of the marker proteins (caspase-3 and PARP) in H1299 and H1975 cells, activated the transcription of IRE1α, increased the expression of GRP78 and XBP-1s, and finally induced apoptosis of H1299 cells. In vivo studies showed that 15 at a dose of 20 mg/kg suppressed tumor growth of S180 cell xenografts in icr mice significantly. Further molecular docking studies suggested that compound 15 could bind well with the ATPase domain of Topoisomerase-II. These data suggest that compound 15 is a promising agent for cancer therapy deserving further research.

Aspergilolide, a steroid lactone produced by an endophytic fungus Aspergillus sp. MBL1612 isolated from Paeonia ostii.

A new steroid lactone aspergilolide (1), and nine known compounds helvolic acid (2), verruculogen (3), tryprostatin B (4), 13-oxofumitremorgin B (5), fumitremorgin C (6), demethoxy fumitremorgin C (7), terezine D (8), aszonalenin (9), 12, 13-dihydroxy-fumitremorgin C (10) from cultures of the endophytic fungus Aspergillus sp. MBL1612. Their chemical structures were determined by a series of extensive spectroscopic methods. All of the compounds were isolated from this genus for the first time. The cytotoxicity against five human cancer cell lines of new compound were detected.

Mimengosides J and K: two new neuroprotective triterpenoids from the fruits of Buddleja lindleyana.

Two new 11-methoxyl substituted triterpenoids, named as mimengosides J (1) and K (2), along with seven known compounds, were isolated from the fruits of Buddleja lindleyana. Their structures were elucidated on the basis of spectroscopic analysis. In addition, the new ones were evaluated for protective effects against damage of SH-SY5Y cells induced by 1-methyl-4-phenylpyridinium ion (MPP+) and the results indicated that those may be one of the candidate compositions of Buddleja lindleyana for the treatment of neurodegenerative disease.

Synthesis and antitumor activity of biotinylated camptothecin derivatives as potent cytotoxic agents.

A series of biotinylated camptothecin derivatives were designed and synthesized. The key to the synthesis was achieved by employing an esterification reaction and click chemistry. All of the new derivatives were tested for cytotoxicity against five human tumor cell lines, including HL-60, SMMC-7721, A-549, MCF-7, and SW480 with IC50 values ranging from 0.13 to 21.53 µM. Most of the derivatives exhibited potent cytotoxicity, especially compound 17 (IC50 = 0.13-3.31 µM) and compound 18 (IC50 = 0.23-1.48 µM), which exhibited the highest potencies. The structure-activity relationships (SARs) of the biotinylated camptothecin derivatives were discussed for exploring novel anticancer agents.

Aspergilates A to E, second metabolites from Aspergillus sp. isolated from Paeonia ostii.

Five novel globoscinic acid derivatives, aspergilates A-E (1-5) have been isolated from endophytic fungus Aspergillus sp. derived from Paeonia ostii. The structures of aspergilates A-E were determined by in-depth analyses of NMR spectra, HRESIMS and CD experiments. The absolute configurations of compounds 2-5 were determined by the ECD calculations based on quantum chemistry. Cytotoxic activities against five selected tested tumor cell lines of 1-5 were evaluated.

Synthesis and anticancer activity of dimeric podophyllotoxin derivatives.

BACKGROUND: Podophyllotoxin is a potent cytotoxic agent and serves as a useful lead compound for the development of antitumor drugs. Several podophyllotoxin-derived antitumor agents, including etoposide, are currently in clinical use; however, their therapeutic efficacy is often limited due to side effects and the development of resistance by cancer cells. Previous studies have shown that 4ß-1,2,3-triazole derivatives of podophyllotoxin exhibit more potent anticancer activity and better binding to topoisomerase-II than etoposide. The effect of dimerization of such derivatives on the anticancer activity has not been studied. METHODS: Two moieties of podophyllotoxin were linked at the C-4 position via 1,2,3-triazole rings to give a series of novel dimeric podophyllotoxin derivatives. 4ß-Azido-substituted podophyllotoxin derivatives (23 and 24) were coupled with various dipropargyl functionalized linkers by utilizing the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction to provide dimeric products in very good yield. The in vitro anticancer activity of the synthesized compounds was evaluated by MTT assay against a panel of five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480). The normal BEAS-2B (lung) cell line was also included for study in order to evaluate the cancer selectivity of the most active compound as compared with normal cells. RESULTS: A group of 16 dimeric podophyllotoxin derivatives with different linkers were synthesized and structurally characterized. Most compounds do not show significant cytotoxicity (IC50 > 40 mM) against all five cancer cell lines. However, one compound (29) which bears a perbutyrylated glucose residue on the glycerol linker is highly potent against all five cancer cell lines tested, with IC50 values ranging from 0.43 to 3.50 µM. This compound (29) also shows good selectivity towards cancer cell lines as compared with the normal BEAS-2B (lung) cell line, showing selectivity indexes from 4.4 to 35.7. CONCLUSION: The anticancer activity of dimeric podophyllotoxin derivatives is generally speaking not improved as compared to their monomeric counterparts, and the potency of these dimeric derivatives can be largely affected by the nature of the linker between the two moieties. Among the synthesized derivatives, compound 29 is significantly more cytotoxic and selective towards cancer cells than etoposide and cisplatin, which are currently in clinical use. Compound 29 is a promising anticancer drug and needs further studies.

Protective effects of cycloartane triterpenoides from Passiflora edulis Sims against glutamate-induced neurotoxicity in PC12 cell.

Four new cycloartane triterpenoids, 1α,3ß-dihydroxy-16-keto-24(31)-en-cycloartane (1), 31-methoxyl-passifloic acid (2), cyclopassifloside XIV (3), and cyclopassifloside XV (4), together with six known compounds (5-10) were isolated from Passiflora edulis Sims. Their structures were elucidated on the basis of extensive spectroscopic analysis. All the compounds were evaluated for protective effects against damage of PC12 cell induced by glutamate according to traditional usage of the herbal medicine, and the results indicated that cycloartane triterpenoids maybe one of the active compositions of P. edulis Sims for the treatment of neurodegenerative disease.

Five new phenolic compounds from Dendrobium aphyllum.

One new phenanthrene, aphyllone A (1) and four new bibenzyl derivatives, aphyllone B (2) and aphyllals C-D (3-5), together with nine known compounds (6-14), were isolated from the stems of Dendrobium aphyllum (Roxb.) C. E. Fischer. The structures of these new compounds were elucidated by means of extensive spectroscopic analyses, and the absolute configuration of compound 1 was determined by single crystal X-ray diffraction and quantum calculations. Compounds 6, 8 and 14 inhibited NO production at the concentration of 25 µM in LPS-stimulated RAW264.7 cells with the inhibition (%) of 32.48, 35.68, and 38.50. Compound 2 possessed significant DPPH radical scavenging activity with scavenging percentage of 87.97% at the concentration of 100 µg/mL.

Cytotoxic bibenzyl dimers from the stems of Dendrobium fimbriatum Hook.

The bioassay-guided chemical investigation of the stems of Dendrobium fimbriatum Hook led to the isolation of seven first reported bibenzyl dimers with a linkage of a methylene moiety, fimbriadimerbibenzyls A-G (1-7), together with a new dihydrophenanthrene derivative (S)-2,4,5,9-tetrahydroxy-9,10-dihydrophenanthrene (8) and thirteen known compounds (9-21). The structure of the new compound was established by spectroscopic analysis. Biological evaluation of bibenzyl derivatives against five human cell lines indicated that seven of those compounds exhibited broad-spectrum and cytotoxic activities with IC50 values ranging from 2.2 to 21.2 µM. Those rare bibenzyl dimers exhibited cytotoxic activities in vitro and the cytotoxicity decreased as the number of oxygen-containing groups in the structure decreases.

Synthesis and anticancer activity of glucosylated podophyllotoxin derivatives linked via 4ß-triazole rings.

A series of 4ß-triazole-linked glucose podophyllotoxin conjugates have been designed and synthesized by employing a click chemistry approach. All the compounds were evaluated for their anticancer activity against a panel of five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, SW480) using MTT assays. Most of these triazole derivatives have good anticancer activity. Among them, compound 35 showed the highest potency against all five cancer cell lines tested, with IC50 values ranging from 0.59 to 2.90 µM, which is significantly more active than the drug etoposide currently in clinical use. Structure-activity relationship analysis reveals that the acyl substitution on the glucose residue, the length of oligoethylene glycol linker, and the 4'-demethylation of podophyllotoxin scaffold can significantly affect the potency of the anticancer activity. Most notably, derivatives with a perbutyrylated glucose residue show much higher activity than their counterparts with either a free glucose or a peracetylated glucose residue.

Inhibitory activities on nitric oxide production of stilbenoids from Pholidota yunnanensis.

Three new stilbenoids, 1-(4'-hydroxybenzyl)-imbricatin, (E)-4'-hydroxy-2',3,3',5-tetramethoxystilbene, and (E)-3,4'-dihydroxy-2,6-bis(4-hydroxybenzyl)-2',3',5-trimethoxystilbene, together with 15 known stilbene derivatives, were isolated from Pholidota yunnanensis. Their structures were elucidated by spectroscopic methods and by comparison of their NMR data with those of related compounds. Furthermore, the inhibitory activities on nitric oxide (NO) production of the isolated compounds were examined in murine macrophages (RAW 264.7) activated by lipopolysaccharide. The cytotoxicity of 18 compounds was determined by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. Among the tested compounds, eight stilbenoids, including three dihydrophenanthrenes, three stilbenes, and one bibenzyl derivative showed inhibitory effects on NO production without cytotoxicity with IC50 values ranging from 4.07 to 7.77 µM, as compared to MG-132, which was used as a positive control (IC50 of 0.10 µM). One dihydrophenanthrene, phoyunnanin C, showed cytotoxic effects at the test concentrations.

[Chemical constituents of Carya cathayensis and their antitumor bioactivity].

OBJECTIVE: To investigate the chemical constituents of Carya cathayensis and their antitumor bioactivity. METHODS: The compounds were isolated by Sephadex LH-20 and silica gel column chromatography. Their structures were identified by physicochemical properties and spectroscopic analysis. Then their cytotoxic activity was studied. RESULTS: Five compounds were elucidated as chrysophanol (1), physcion (2), beta-sitosterol (3), pinostrobin(4), 4,8-dihydroxy-1-tetralone (5). CONCLUSION: Compounds 2 and 5 are isolated from Carya cathayensis for the first time. In the MTT antitumor experiments, the compounds 1,4 and 5 have the cytotoxic activity to KB cell.