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A series of novel isosteviol-derived alkenyl ethers were synthesized and structurally characterized by IR, NMR, and HR-MS. The tested compounds are more sensitive to Gram-positive bacteria than to Gram-negative bacteria. In particular, compound 5 exhibited better bacteriostatic activity against B. subtilis with a minimum inhibitory concentration of 2.403 mM, whereas compounds 8 and 10 selectively inhibited the S. aureus strain. [ABSTRACT FROM AUTHOR]

A novel compound lactam of 15β-hydroxymethylisosteviol ethyl ester 3 has been synthesized and structurally characterized by IR, NMR, and HR-MS. Its X-ray crystallographic analysis revealed that the nitrogen is attached to C-13 instead of C-15. The reaction mechanism was discussed, and the title compound was further evaluated against HCT-116, HGC-27, and JEKO-1 cells by the MTT assay. The results demonstrated that compound 3 exhibited better cytotoxic activities than its corresponding precursor isosteviol. [ABSTRACT FROM AUTHOR]

Eight new stigmasterol derivatives possessing 1,2,3-triazoles moiety were synthesized by a 1,3-dipolar cycloaddition reaction. All the compounds were characterized by IR, NMR, and HR-MS. In addition, human cervical cancer cells (HeLa), human gastric cancer cells (HGC-27), and human renal epithelial cells (HEK-293T) were selected to study the antitumor activity of the synthesized compounds. The results demonstrated that compounds 3c and 3d exhibited better inhibitory activity against the tested tumor cell lines. The IC50 value of the inhibitory activity on HeLa was 52.3 μmol·L–1 and 31.4 μmol·L–1, and 40.6 μmol·L–1 and 44.6 μmol·L–1 for HGC-27, respectively. [ABSTRACT FROM AUTHOR]

Two series of novel acylthiosemicarbazide and oxadiazole fused-isosteviol derivatives were synthesized based on the 19-carboxyl modification. The target compounds were evaluated for their cytotoxicities against three cancer cell lines ( HCT-116, HGC-27, and JEKO-1) using an MTT assay. Lead compounds from the acylthiosemicarbazides ( 4) showed IC50 values in the lower micromolar range. For example, compounds ( 4i, 4l, 4m, 4r, and 4s) exhibited significant inhibitory activities against the three cell lines with IC50 values of 0.95-3.36 μ m. Furthermore, 2D- HQSAR and 3D-topomer Co MFA analyses were established, which could be used to develop second generation of isosteviol derivatives as anticancer agents. [ABSTRACT FROM AUTHOR]

A series of novel 1,2,3-triazole-linked isosteviol derivatives were designed and synthesized via Huisgen-click reaction. Their cytotoxicities in vitro against HCT-116 and JEKO-1 cells were screened. The preliminary bioassays indicated that most of the title compounds exhibited noteworthy cytotoxic activities. Particularly, the compound 10b revealed the most potent inhibitory activities against HCT-116 cells with IC 50 value of 2.987 ± 0.098 μM, which was better than that (3.906 ± 0.261 μM) of positive control cisplatin. On the basis of these bioactivity data, hologram quantitative structure–activity relationship (HQSAR) was performed, and a statistically reliable model with good predictive power ( r 2 = 0.848, q 2 = 0.544 and R 2 pred = 0.982) was achieved. Additionally, the contribution maps derived from the optimal model explained the individual atomic contributions to the activity for each molecule. [ABSTRACT FROM AUTHOR]

A series of novel isosteviol derivatives bearing amino alcohol and thiourea fragments have been stereo-selectively synthesized and screened for their in vitro cytotoxic activities against three human cancer cell lines (HCT-116, HGC-27 and JEKO-1). The results demonstrated that these compounds exhibited prominent cytotoxicities. Especially, the compound Iw displayed the most potent anticancer activities against HCT-116 cell with IC 50 value of 1.450 μM. On the basis of this bioassay results, these derivatives were further investigated by the hologram quantitative structure–activity relationship (HQSAR) technique. The optimal HQSAR model with q 2 = 0.663, r 2 = 0.895, SEE = 0.179 was generated using A/B/H/Ch as fragment distinction parameters and 4–7 as fragment size. This model was employed to predict the cytotoxic activities of test set compounds, and the predicted values were in good agreement with the experimental results. The contribution maps derived from the optimal model explained the individual atomic contribution to the total activity of single molecule. [ABSTRACT FROM AUTHOR]

Objective: Dehydroepiandrosterone plays an important role in the human beings due to its ability to be converted into androgens and oestrogens. The aim of this paper is to synthesize a series of novel dehydroepiandrosteronyl 1,2,3-triazole derivatives and study the antitumor activity of the synthesized compounds. Methods: Novel dehydroepiandrosteronyl 1,2,3-triazole derivatives were synthesized across the Mitsunobu and click reaction, respectively. The cytotoxicities of the synthesized compounds against HeLa, HGC-27, and HEK-293T cells were determined by MTT assay. Results and Discussion: The results showed that compound (V) (3R,8R,9S,10R,13S,14S)3-(4-(4-methoxyphenyl)-1H-1,2,3-triazol-1-yl)-10,13-dimethyl-1,2,3,4,7,8,9,10,11,12,13,14,15,16-tetradecahydro17H-cyclopenta[a]phenanthren-17-one had better inhibitory activity against the tumor cell lines tested. The IC50 value of inhibitory activity on human cervical cancer cell (HeLa) and human gastric cancer cell (HGC-27) was 33.6 and 22.3 μmolL–1, respectively. Conclusions: This work provides useful strategies for the design and synthesis of new steroidal antitumor drugs. The synthesized compounds have certain inhibitory activity on tumor cell growth and proliferation, but have little damage on normal cells, which deserves further study. [ABSTRACT FROM AUTHOR]

An efficient Ir(III)-catalyzed decarbonylative annulation of salicylaldehydes with cyclohexane-1,3-diones has been achieved via the in situ generated iodonium ylides. The reaction proceeds smoothly under mild and operationally simple conditions, affording a variety of benzofuran derivatives in moderate to high yields with good functional group tolerance. Moreover, the large-scale synthesis and further modification of the products highlight the utility of this protocol. [ABSTRACT FROM AUTHOR]

Abstract: Two series of novel isosteviol-fused pyrazoline and pyrazole derivatives were facilely synthesized via intramolecular 1,3-dipolar cycloaddition and condensation reaction, respectively. All compounds were characterized by NMR, IR and HRMS spectra. The stereochemistry of compounds 9b, 10, 11a and 11v were further confirmed by X-ray crystallographic analysis. The antiproliferative activities of the structurally related pyrazoline and pyrazole derivatives were tested in vitro on four human malignant cell lines (SGC 7901, A549, Raji and HeLa): Our results revealed that isosteviol-fused pyrazole derivatives exhibited noteworthy cytotoxic activities. Among them, 2,4-di-Cl-phenylpyrazole derivative 11t displayed better cytotoxities with IC50 values: 2.71, 3.18, 1.09 and 13.52 μM against SGC 7901, A549, Raji and HeLa, respectively, compared to cisplatin (IC50 values: 7.56, 17.78, 17.32 and 14.31 μM, respectively). [Copyright &y& Elsevier]

Abstract: Two series of novel carbothioamide-substituted pyrazole and isoxazolidine derivatives were facilely prepared by functional interconversions in ring D of the tetracyclic diterpene isosteviol. The in vitro cytotoxic activities against four human tumor cell lines were evaluated. Our results indicated that carbothioamide-substituted pyrazole derivatives exhibited noteworthy cytotoxic activities. Specifically, compound 12p (IC50 =6.51μM) had the most potent cytotoxicity against Raji cell, which may be exploitable as a lead compound for the development of potent antitumor agents. [Copyright &y& Elsevier]

The synthesis of novel isosteviol-fused pyrazolines and pyrazoles from isosteviol is described along with the evaluation of the anti-cancer activity of the synthesized compounds. [ABSTRACT FROM AUTHOR]

Abstract: Considerable interest has been attracted in isosteviol and its derivatives because of their large variety of pharmacological activities. In this project, a series of novel compounds containing hydroxyl, hydroxymethyl group and heteroatom-containing frameworks fused with isosteviol structure were synthesized and evaluated as α-glucosidase inhibitors, aimed at clarifying the structure–activity correlation. The results indicated that these isosteviol derivatives were capable of inhibiting in vitro α-glucosidase with moderate to good activities. Among them, indole derivative 15b exhibited the highest activities and thus may be exploitable as a lead compound for the development of potent α-glucosidase inhibitors. [Copyright &y& Elsevier]