Design, Synthesis, and Biological Evaluation of Artemisinin-Piperazine-Phosphoramide Mustard Hybrids as Potential Anticancer Agents.

A series of novel artemisinin-piperazine-phosphoramide mustard (PPM) hybrids were designed and synthesized by incorporating phosphoramide mustard (PM) into dihydroartemisinin (DHA) via an efficient, catalyst-free two-step sequential substitution. Artemisinin-PPM hybrids showed better cytotoxic potency against HepG2 cells than both the parent DHA and the reference, vincristine (VCR). Structure-activity relationship (SAR) studies showed that the cytotoxicity was significantly enhanced by the introduction of a thiazole moiety. Hybrid 7 h, the most potent compound with the highest selectivity index IC50 (HEK-293T)/IC50 (HepG2)=16, displayed 7.4-fold stronger potency than VCR against HepG2 cells. In addition, hybrid 7 h was substantially more cytotoxic on all human cancer cells tested than on the corresponding non-cancerous cells. Flow cytometric analysis showed that 7 h significantly blocked the cell cycle in the G0/G1 phase and induced apoptosis in a concentration-dependent manner.

Synthesis of artemisinin-piperazine-furan ether hybrids and evaluation of in vitro cytotoxic activity.

For the first time, eight novel artemisinin-piperazine-furane ether hybrids (5a-h) were efficiently synthesized and investigated for their in vitro cytotoxic activity against some human cancer and benign cells. The absolute configuration of hybrid 5c was determined by X-ray crystallographic analysis. Hybrids 5a-h exhibited more pronounced growth-inhibiting action on hepatocarcinoma cell lines than their parent dihydroartemisinin (DHA) and the reference cytosine arabinoside (ARA). The hybrid 5a showed the best cytotoxic activity against human hepatocarcinoma cells SMMC-7721 (IC50 = 0.26 ± 0.03 µM) after 24 h. Furthermore, hybrid 5a also showed good cytotoxic activity against human breast cancer cells MCF-7 and low cytotoxicity against human breast benign cells MCF-10A in vitro. We found the cytotoxicity of hybrid 5a did not change when tumour cells absorb iron sulfate (FeSO4); thus, we conclude the anti-tumour mechanism induced by iron ions (Fe2+) is unclear.

Synthesis and biological evaluation of novel artemisone-piperazine-tetronamide hybrids.

For the first time, six novel artemisone-piperazine-tetronamide hybrids (12a-f) were efficiently synthesised from dihydroartemisinin (DHA) and investigated for their in vitro cytotoxicity against some human cancer cells and benign cells. All the targets showed good cytotoxic activity in vitro. Hybrid 12a exhibited much better inhibitory activity against human liver cancer cell line SMMC-7721 (IC50 = 0.03 ± 0.04 µM for 24 h) than the parent DHA (IC50 > 0.7 µM), and two references, vincristine (VCR; IC50 = 0.27 ± 0.03 µM) & cytosine arabinoside (ARA; IC50 = 0.63 ± 0.04 µM). Furthermore, hybrid 12a had low toxicity against human benign liver cell line LO2 (IC50 = 0.70 ± 0.02 µM for 24 h) compared with VCR, ARA, and DHA in vitro. Moreover, the inhibitory activity of hybrid 12a was obviously enhanced when human liver cancer cell line MHCC97H absorbed Fe2+ in vitro.

Synthesis and biological activities of artemisinin-piperazine-dithiocarbamate derivatives.

Twelve derivatives of artemisinin-piperazine-dithiocarbamate have been synthesised, and some of them showing good in vitro cytotoxic activity. Compound 3g exhibits the best inhibitory activity against SMMC-7721 cell lines with an IC50 of 0.0025 ±â€¯0.04 µM for 72 h, but the toxicity was lower against LO2 cell lines with an IC50 of 0.18 ±â€¯0.04 µM for 72 h. The results indicate that compound 3g is more cytotoxic towards cancer cell lines than towards benign cell lines compared with vincristine in vitro. And compound 3g also has good inhibitory activity against colon, breast and prostate cancer cells. Meanwhile, we have also proposed the six-member ring mechanism of DMSO in catalysing the esterification of hydroxyl and acyl chloride. Instead of using the hydroxyl, we can obtain the nucleophilic substitution production simply and efficiently without a Lewis acid, which has not been reported previously.

Synthesis and biological activities of dithiocarbamates containing 2(5H)-furanone-piperazine.

A series of new dithiocarbamates containing a 2(5H)-furanone-piperazine group was synthesized. These compounds show good in vitro cytoxic activity. Among them, compound 6c exhibits the best inhibitory activity against HeLa cell lines with an IC50 of 0.06 ±â€¯0.01 µM for 72 h, and it has good inhibitory activity against SMMC-7721 cell lines with an IC50 of 0.006 ±â€¯0.04 µM for 72 h, but the toxicity was lower against LO2 cell lines with an IC50 of 45.76 ±â€¯0.01 µM. The result showed that compound 6c is far more cytoxic towards cancer cell lines than towards benign cell lines compared with cytosine arabinoside (ARA) in vitro.

[Cloning of Taenia pisiformis Actin Gene and Assessment of Its Use as An Internal Control].

Objective: To clone the full-length cDNA of actin gene of Taenia pisiformis (Tp-actin), and analyze the gene structure, phylogenetic evolution and its use as an internal control. Methods: Tp-actin was amplified by RT-PCR and the cDNA of 3' and 5' ends were obtained through RACE-PCR. After sequencing, these segments were linked to produce full-length cDNA of Tp-actin. The gene structure and phylogenetic evolution were analyzed using bioinformatics software. Primers for Tp-actin and cysteine peptidase (TpCP) were designed using Primer Express software. Primer specificity and amplification efficiency were analyzed with real-time fluorescence quantitative PCR (qRT-PCR). In addition, by using Tp-actin as an internal control, the expression of TpCP in T. pisiformis at various developmental stages was analyzed. Results: As expected, sequencing results showed that the Tp-actin fragment was 1 048 bp in length, and the 3' and 5' ends were 428 bp and 945 bp, respectively. The full-length cDNA of Tp-actin generated from the 3 segments (submitted to GenBank with accession No. JX624787) was 1 279 bp, containing a 30-bp 5'-untranslated region（5'-UTR）, a 118-bp 3'-UTR, and a 1 131-bp open reading frame (ORF). Bioinformatics analysis showed that the Tp-actin encoded a protein of 356 amino acids, with a predicted relative molecular weight of 41 749 and a PI value of 5.29. This protein was predicted to contain 6 functional sites and 3 typical signatures of the actin family. Phylogenetic analysis showed that the Tp-actin was 100% and 99.7% homologous in amino acid sequence to those of Taenia solium and Diphyllobothrium dendriticum. qRT-PCR resulted in specific products of 82 bp and 108 bp from Tp-actin and TpCP, respectively, melting curves of which both showed a single signal peak, verifying the high specificity of primers. The linear correlation coefficient（R2） in standard curve of Tp-actin was 0.999, showing high amplification efficiency. Using Tp-actin as the internal control, the relative expression ratio of TpCP gene in gravid proglottid of T. pisiformis（1.65） was significantly higher than that in oncospheres （1.00）, mature proglottids （0.87） and cysticercus (0.62) (P<0.05). Conclusion: Tp-actin gene is highly conserved and can be used as a reliable internal control.

[Effect of inhibiting TIM-4 function in Kupffer cells on liver graft rejection in mice].

OBJECTIVE: To investigate the effects of inhibiting TIM-4 function in Kupffer cells (KCs) on liver graft rejection in mice and explore the underlying mechanism. METHODS: Mouse models of orthotopic liver transplantation were treated with a control mAb group and TIM-4 mAb. The activated KCs were assayed with immunohistochemistry after operation. The expression of TIM-4 in KCs were assayed with Western blotting and RT-PCR and the levels of AST, ALT, TBIL, TNF-α, IFN-γ and CCL2 were assayed detected. The expression of TIM-4 in KCs was observed with laser confocal microscopy. HE staining was used to observe the microstructure of the liver tissues, and the number of CD25+Foxp3+T cells was determined using with flow cytometry; the proteins levels of p-P65and p-P38 were assayed with Western blotting. The donor mice were treated with clodronate liposomes to destroy the KCs in the liver before transplantation, and the liver grafts were examined for graft rejection. RESULTS: The number of activated KCs in the liver graft increased progressively over time. Compared with the sham-operated group, the liver graft showed significantly increased TIM-4 protein and mRNA levels at 1, 3, and 7 days after transplantation (P<0.05) and increased levels of AST, ALT, TBIL, TNF-α, IFN-γ and CCL2 at 7 days (P<0.05). The graft in TIM-4 mAb group showed mild pathological changes with a mean RAI score of 2.67∓0.75, which was significantly lower than that in control mAb group (P<0.05). The mean survival time of the recipient mice was 53.8∓6.4 days in TIM-4 mAb group, significantly longer than that in the control mAB group (14.5∓2.9 days, P<0.05). Donor treatment with clodronate liposomes resulted in comparable RAI scores in TIM-4 mAb and control mAb groups (8.01∓0.64 vs 7.93∓0.56, P>0.05). The protein levels of p-P65 and p-P38 in TIM-4 mAb group were significantly lower than those in control mAb group (P<0.05), and CD25+Foxp3+T cells in the liver graft increased significantly in TIM-4 mAb group. CONCLUSION: Inhibition of TIM-4 function in KCs reduces the production of inflammatory factors after liver transplantation possibly by inhibiting the NF-κB and MAPK signaling pathways and promoting the proliferation of Foxp3+Treg cells to induce allograft tolerance.

Intramolecular Schmidt reaction of acyl chlorides with alkyl azides: capture of N-acyliminium ion intermediates with aromatic rings.

Intramolecular Schmidt reaction of acyl chlorides with alkyl azides through N-acyliminium ion intermediates is designed and realized. The intramolecular capture of the intermediates with aromatic rings affords several nitrogen-containing tricyclic skeletons. The important feature of the domino process is the efficiency in bond reorganization and ring formation.

[Synthesis and bioactivities of novel dihydroartemisinin-piperazine derivatives containing sulfonamide].

Dihydroartemisinin is an important derivative of artemisinin. We used dihydroartemisinin as the starting material, through esterification, amination and acylation, a series of novel piperazine-sulfonamide contained dihydroartemisinin derivatives were firstly synthesized and their chemical structures were confirmed by IR, 1H NMR, 13C NMR and HR-MS. X-diffraction was used to determine the final configuration of the compound 3c. And the in vitro anti-HeLa activities of compounds 3 were analyzed with CCK-8 method. The preliminary bioassay test shows that compound 3 showed the best inhibition activities against HeLa with IC50 values of 0.14 micromol x L(-1).

A formal metal-free N-arylation via the Schmidt reaction of aromatic aldehydes with an azido amine.

A formal metal-free N-arylation of aromatic aldehydes with 3-azido-N-tosylpropan-1-amine through the Schmidt process was realized in the presence of acids. TfOH was found to be a good promoter, and the exclusive 1,2-aryl migration was observed. Furthermore, the conversion of an aliphatic aldehyde to the N,N-disubstituted formamide was achieved in excellent yield.

Intramolecular Schmidt reaction of acyl chlorides with alkyl azides: rapid access to fused polycyclic nitrogen-containing heterocycles via a multistep one-pot transformation.

The first intramolecular Schmidt reaction of acyl chlorides with alkyl azides has been developed. In this one-pot conversion, an ω-azido hydrocinnamic acid is converted to a tricyclic lactam. The most important feature of the process is the efficiency in bond formation (one bond broken and three new bonds created) and ring construction (two new rings formed).

Synthesis and evaluation of antitumor activities of novel chiral 1,2,4-triazole Schiff bases bearing γ-butenolide moiety.

BACKGROUND: 1,2,4-Triazole derivatives have received much attention due to their versatile biological properties including antibacterial, antifungal, anticonvulsant, antiinflammatory, anticancer, and antiproliferative properties. 1,2,4-Triazole nucleus has been incorporated into a wide variety of therapeutically interesting molecules to transform them into better drugs. Schiff bases of 1,2,4-triazoles have also been found to possess extensive biological activities. On the other hand, γ-substituted butenolide moiety represents a biological important entity that is present in numerous biologically active natural products. RESULTS: We have described herein the synthesis of 12 hybrid 1,2,4-triazole Schiff bases bearing γ-substituted butenolide moiety. These compounds were synthesized by utilizing the tandem asymmetric Michael addition/elimination reaction as the key step. All the new compounds were evaluated for their in vitro anticancer activity. CONCLUSIONS: Tandem asymmetric Michael addition/elimination approach has offered an easy access to new chiral 1,2,4-triazole compounds 7a-7l. All these chiral 1,2,4-triazole derivatives exhibited good anticancer activities towards Hela. Of all the tested compounds, the chiral compound 7l with an IC50 of 1.8 µM was found to be the most active.

Synthesis of new chiral 2,5-disubstituted 1,3,4-thiadiazoles possessing gamma-butenolide moiety and preliminary evaluation of in vitro anticancer activity.

A new series of chiral 1,3,4-thiadiazoles derivatives possessing gamma-substituted butenolide moiety were synthesized and evaluated for in vitro anticancer properties. All the compounds showed good anticancer activities against Hela cell lines. Of all the studied compounds, compound 9e exhibited the best inhibitory activity with an IC(50) of 0.9 microM. After being treated with 0.1 microg/mL compound 9e for 24h, the growth inhibition rate of Hela cell lines was 59.2%.