Design, synthesis and anti-tumor activity of asiatic acid derivatives as VEGF inhibitors.

The VEGF receptor is mock-coupled with a known active compound and the active groups of the inhibitor which can bind to VEGF were analyzed. Using asiatic acid as a lead compound, 10 novel skeleton candidate compounds were designed through introduction of the active groups onto the special location and synthesized simultaneously. Furthermore, the structure of these compounds was determined by 1H NMR, 13C NMR and MS and 9 compounds were identified as the new compounds. Moreover, the in vitro anti-tumor activities of these new compounds were determined by MTT assay on two cancer cell lines (HepG2 and SGC-7901). The results showed that compounds I1 and II2 have more potent anticancer activity than positive control drugs such as gefitinib and paclitaxel.

Synthesis and anti-tumor activity of asiatic acid derivatives targeting VEGFR.

To discovery novel VEGFR inhibitors, 12 novel asiatic acid derivatives were designed by computer-aided drug design (CADD) technology. Then, these novel asiatic acid derivatives were synthesized by introducing active groups at ring A and C-28 positions of asiatic acid. The structures of these novel analogues were confirmed by NMR and MS. Moreover, the anti-tumor activities of these novel asiatic acid derivatives on human hepatoma cells HepG2 and human gastric cancer cells SGC7901 were evaluated by MTT assay. As a result, compounds I2 and II4 showed stronger cytotoxicity on tumor cells than asiatic acid and positive control drugs such as gefitinib and paclitaxel. In conclusion, our study synthesized twelve novel asiatic acid derivatives and determined compounds I2 and II4 had better anti-tumor effect which may be potential candidate compounds for tumor therapy.

Design, synthesis and bioactivities evaluation of novel oleanolic acid derivatives as potent PI3K inhibitors.

Oleanolic acid has previously been shown to possess PI3K inhibitory activity, thus, the purpose of this work was to generate a series of derivatives that improve the potency. Twenty rationally designed oleanolic acid derivatives were synthesized and tested the cytotoxicity and PI3K inhibitory activity. The results suggested that attachment of additional structural elements such as association of thiazole group to A ring and insertion of phenylurea group was important for increasing activities. The most active derivative was compound II2, which exhibited PI3K inhibitory activity (IC50 = 58.42 nmol/l) and improved interaction with activity site of PI3K according with docking studies.

Design and synthesis of VEGFR-2 inhibitors based on oleanolic acid moiety.

In this study, twenty-four oleanolic acid (OA) derivatives were rationally designed based on molecule docking studies and their VEGFR-2 inhibitory activities were tested by Homogeneous time-resolved fluorescence (HTRF) method in vitro. All of the synthesized compounds were identified as new compounds, and the structures of these compounds were determined by 1H-NMR and ESI-MS. In the screening for VEGFR-2 inhibitors, compounds I6 and I7 exhibited excellent inhibitory effect. The results indicated that insertion of phenylurea group with a linker at position C-28 of OA can increase the activity against VEGFR-2 significantly. [Formula: see text].

Synthesis of oleanolic acid analogues targeting PDGF receptor inhibitors and their antitumor biological activities.

The PDGF receptor is mock-coupled with a known active compound, and 14 novel skeleton candidate compounds were designed and synthesized. The structure was confirmed by 1H NMR, 13C NMR and MS. The in vitro cytotoxicity of the two cancer cell lines (SGC-7901 and A549) was evaluated by MTT assay. PDGF receptor protein inhibition assays were performed on I6 and II4 using fluorescence polarization immunoassay (FPIA). [Formula: see text].

Synthesis and antitumor activity evaluation of ursolic acid derivatives.

Eighteen uronic acid derivatives were designed and synthesized, and the cytotoxicities in vitro of two cancer cell lines (BEL7402 and SGC7901) were evaluated by MTT assay. The results showed that the inhibitory rate of the compounds on both cell lines was significantly higher than the parent compound. The IC50 of compounds II4, II6, III4, and III6 are comparable or stronger than the positive control drug, the interactions between compounds II4, II6, III4, III6, and NF-κB were also studied by docking simulations.

Synthesis and anti-tumor activity of derivatives of ring A of asiatic acid.

Based on the simulation of the docking of survivin protein with known small molecule inhibitors, the active groups which can bind to target proteins were analyzed by the techniques of computer-aided drug design (CADD). These active groups were introduced into the A-ring of asiatic acid and their C-28 sites were reconstructed simultaneously. Ten asiatic acid derivatives were designed and synthesized, and their structures were confirmed by MS and NMR. The inhibitory activities of the asiatic acid derivatives against HepG2 and SGC7901 cell lines were evaluated and confirmed by the tetrazolium bromidesalt (MTT) assay. The results showed that compounds I6 and II4 exhibited more potent cytotoxicity than the positive control drug gefitinib, which was comparable to that of adriamycin.[Formula: see text].

Design, synthesis, and antitumor activity of oleanolic acid derivatives.

Using the techniques of computer-aided drug design, the docking of survivin and known active small molecules was simulated and then the key amino acid residue fragments of the target protein were analyzed. It led to the discovery of active groups capable of binding to the critical sites. Through the use of the natural product, oleanolic acid, as a lead compound, the introduction of the active groups onto the A-ring, and the modification of the carboxyl group at the C-28 position using esterification or amidation, 20 new oleanolic acid derivatives had been designed and synthesized. HepG2 and SGC-7901 cells were used to screen the antitumor activity through the standard MTT method. The compounds, II3, III5 and IV4, exhibited more potent cytotoxicity than positive drugs. Western blot experiment demonstrated that compound II3 can effectively inhibit the proliferation of HepG2 cells.

Synthesis and antitumor activity evaluation of asiatic acid derivatives as survivin inhibitor.

A series of asiatic acid derivatives were synthesized and their cytotoxicities in vitro against two cancer cell lines (HepG2 and SGC7901) were evaluated by MTT assay. The results showed that compounds I2, I6, and II6 have more potent anticancer activity than that of the positive control drug paclitaxel. The interactions between the compounds I2, I6, and II6 and survivin were also studied by docking simulations.

Synthesis and antitumor activity evaluation of novel oleanolic acid derivatives.

Ten novel oleanolic acid (OA) derivatives were synthesized through modifications at positions of A ring and C-28. Inhibitory activities of the oleanolic acid derivatives against SGC7901 and A549 cell lines were evaluated and confirmed by the tetrazolium bromidesalt (MTT) assay. The lab results revealed that all these compounds displayed some antitumor activity against SGC-7901 and A-549 cell lines. Among them, II4 and II5 exhibited excellent antitumor activities against SGC7901 cells and A549 cells, compared with gefitinib. Molecular docking studies have shown that compounds II4 and II5 produce potent antitumor activities by interacting with C-kit receptor through hydrogen bonds and hydrophobic bonds.

Synthesis and antitumor activity evaluation of novel ursolic acid derivatives.

Eleven novel ursolic acid (UA) derivatives were designed and synthesized with modification at positions of C-2, C-3, and C-28 of UA. Their structures were confirmed by MS, (1)H NMR, and elemental analysis. Their in vitro cytotoxicities against various cancer cell lines (HeLa, HepG2, and BGC-823) were evaluated by MTT assay. The results indicated that all compounds could inhibit cell proliferation of HeLa, HepG2, and BGC-823 cells. Among them, compounds I3 and I4 showed more potent cytotoxicity on these three tumor cells than gefitinib (positive control), worthy to be studied further.

[Advances in study of Survivin inhibitors].

Survivin, a member of the inhibitor of apoptosis proteins family, is considered to be an important target of anticancer treatment for its key role in the control of cell division and cell apoptosis. Currently, only a few Survivin inhibitors have been developed, and most of them reduce Survivin level by interacting with other biomolecules instead of directly interacting with Survivin protein. This review summarizes the structure of Survivin protein, the mechanism of action and research progress of Survivin inhibitors, which may has a great significance in the study of selective Survivin inhibitors in the future.

[Synthesis and anti-tumor activity of oleanolic acid derivatives].

Thirteen novel oleanolic acid (OA) derivatives were designed and synthesized with modification at positions of C-3, C-12 and C-28 of OA. Their structures were confirmed by MS, 1H NMR and elemental analysis. Their in vitro cytotoxicities against various cancer cell lines (SGC7901, MCF-7 and A549) were evaluated by MTT assay. The results indicated that the tested derivatives were found to have stronger cell growth inhibitory activity than OA. Among them, compounds II2 and II3 showed more potent cytotoxicity on MCF-7 and A549 tumor cells than gefitinib (positive control). They are worthy to be studied further.

Synthesis and antitumor activity evaluation of new asiatic acid derivatives.

Twelve novel asiatic acid (AA) derivatives were designed and synthesized. Their structures were confirmed using NMR, MS, and IR spectra. Their in vitro cytotoxicities on various cancer cell lines (HeLa, HepG2, BGC-823, and SKOV3) were evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. Most of the derivatives were found to have stronger cell growth inhibitory activity than AA. Among them, compounds 5-8 and 11 with substituted amide group at C-28 exhibited more potent cytotoxicity than AA, Gefitinib, and etoposide (positive control).

[Synthesis and anti-tumor activity of ursolic acid derivatives].

Structure of natural product-ursolic acid was modified for increasing its antitumor activity. Ursolic acid was acylated, esterified, hydrolized or oxidized to obtain target pentacyclic triterpenoid compounds with different substitutes. Sixteen derivatives of ursolic acid were designed and synthesized including eleven new compounds. Anti-tumor activities of ursolic acid and these derivatives against HeLa, SKOV3 and BGC-823 cells in vitro were investigated by MTT assay. The results indicated that compounds 7a and 8a were found to have stronger cell growth inhibitory than ursolic acid on HeLa cells and SKOV3 cells separately, and are worth to be intensively studied further.

[Synthesis and anti-tumor activity of oleanolic acid derivatives].

Structural modifications were performed with natural product of oleanolic acid to search for novel anticancer drugs. Ten oleanolic acid derivatives were designed and obtained by the reaction of oxidation, acylation or hydrolyzation, etc. The cytotoxic activity of derivatives was evaluated against HeLa, HepG2 and BGC-823 cells in vitro by MTT assay, gefitinib and etoposide used as a positive control. The results showed that compound 5a was particularly active to inhibit HepG2 cells growth, and anti-tumor activity of compound 7 on HeLa cells was significantly stronger than oleanolic acid. They are worthy to be studied further.

The synthesis of ursolic acid derivatives with cytotoxic activity and the investigation of their preliminary mechanism of action.

Nineteen ursolic acid derivatives (15 novel compounds) modified at the C-3 and the C-28 positions were synthesized. The cytotoxic activity of the derivatives was evaluated against HeLa, BGC-823 and SKOV3 cells by MTT assay. Inducing apoptosis and affecting cell cycle distribution by the derivatives in HeLa cells were assessed by flow cytometry and DNA fragmentation. Compounds 10b and 11b were particularly active to inhibit HeLa cells growth through inducing apoptosis and arresting cell cycle progression. The typical 'sub-G1 peak' and DNA ladder formation were checked and cell cycle was arrested at the S phase in a dose-dependent manner.