The effect of environmental credit rating on audit fees: A quasi-natural experiment from China.

Environmental credit rating (ECR) is a new policy that deeply integrates the construction of ecological civilisation and the social credit system in China; however, there is a paucity of research on the response of external auditors to the ECR. This study takes the environmental credit evaluation policy implementation as a quasi-natural experiment, using China's A-share listed companies in heavily polluting industries from 2008 to 2019 as samples. We construct a heterogeneous timing difference-in-differences model to empirically explore the impact of ECR on audit fees. The results show that the ECR significantly reduces companies' audit fees. Importantly, our analysis suggests that the ECR improves environmental information transparency and enhances sustainable operation ability, thereby reducing audit fees. Further analysis shows that the negative correlation between the ECR and audit fees is more obvious in non-state enterprises, in poor legal environments and low levels of trust. Our study provides scientific evidence for the economic consequences of the environmental credit evaluation policy and enriches the literature on the factors affecting audit fees. It has revelatory significance for China and other developing countries to implement and improve the environmental credit evaluation policies and better guide enterprises to fulfil their environmental responsibilities.

Anticancer evaluation of benzofuran derivatives linked to dipiperazine moiety.

In this work, a series of novel benzofuran derivatives linked to dipiperazine moiety have been prepared, and in vitro anticancer activity against Hela and A549 was investigated. The results demonstrated that benzofuran derivatives exerted potent antitumor effect. Especially, compounds 8c and 8d showed better antitumor activity against A549 (IC50 = 0.12 µM and 0.43 µM). Further mechanism study indicated that compound 8d could significantly induce cell apoptosis in A549 by FACs analysis.

Synthesis and Cytotoxic Activity of Quinazoline-Benzofuran Conjugates.

AIMS: In order to study on structure-activity relationships of benzofurans. BACKGROUND: Benzofuran is a kind of natural compound widely existing in nature with pharmacological effects. The development of new anticancer benzofuran derivatives has attracted more and more attention. METHOD: We have introduced an active quinazoline unit into piperazine-substituted benzofuran, prepared a series of quinazoline-benzofuran compounds, and evaluated cytotoxic activity against a panel of human tumor cell lines by MTT assay. RESULT: 48 novel quinazoline-substituted benzofuran derivatives have been prepared, and in vitro, cytotoxic activity against five human tumor cell lines was evaluated. The results indicated that some quinazoline-benzofuran conjugates showed selective inhibitory activity against tumor cell lines. CONCLUSION: We have found that compound 14x displayed excellent cytotoxic activity, which could be considered a potential anticancer agent.

A two-dimensional Te/ReS2 van der Waals heterostructure photodetector with high photoresponsivity and fast photoresponse.

Two-dimensional (2D) semiconductors are the building blocks for high-performance optoelectronic devices. However, the performance of photoconductive photodetectors based on 2D semiconductors is hampered by low photoresponsivity and large dark current. Herein, a van der Waals heterostructure (vdWH) composed of rhenium disulfide (ReS2) and tellurium (Te) is fabricated. The Te/ReS2 vdWH photodetector exhibits a sensitive and broadband photoresponse and has high photoresponse on/off ratios under ultraviolet and visible light illumination, especially over 102 in visible light. The Te/ReS2 vdWH photodetector achieves the responsivity of 7.9 A W-1 at 365 nm, 3.02 A W-1 at 450 nm, 2.37 A W-1 at 532 nm, and 2.45 A W-1 at 660 nm. In addition, the device achieves a high specific detectivity of 1011 Jones and a fast photoresponse speed of 11.9 µs. Such high responsivity could be attributed to the efficient absorption of phonons by the Te/ReS2 vdWH and the high-quality heterostructure interfaces with a small amount of trap states. The highly crystalline structure of Te/ReS2 with a low density of defects reduces the grain boundary scattering, leading to the rapid diffusion of charge carriers. Moreover, the Te/ReS2 vdWH device exhibits a photovoltaic effect and can be employed as a self-powered photodetector (SPPD), which is sensitive to visible light of 450 nm, 532 nm, and 660 nm. Our findings demonstrate that the Te/ReS2 vdWH photodetector is an ideal building block for the next-generation electronic and optoelectronic devices in practical applications.

Cu(II)/Vasicine Promoted Intramolecular C-O Formation: Synthesis of Benzoxazoles in EtOH.

AIMS AND OBJECTIVES: Benzoxazoles are valuable bicyclic aromatic compounds; the construction of benzoxazoles via C-O cross-coupling reactions has attracted more and more attention. MATERIALS AND METHODS: The best condition of C-O bond formation from o-haloanilides was carried out, taking Cu(OTf)2 (5 mol%) and vasicine (10 mol%) as the catalysts in EtOH in the presence of K2CO3 (2 eq.) for 12 h at 90°C. RESULTS: A series of 2-substituted benzoxazoles have been prepared in high yields from 2-bromoanilides and 2- iodioanilides under mild conditions. CONCLUSION: We have developed an efficient Cu-vasicine catalytic system for intramolecular C-O bond formation. This strategy is applicable to the synthesis of a wide variety of 2-substituted benzoxazoles by intramolecular O-arylation of o-haloanilides.

Synthesis of New Piperazine Substituted Chalcone Sulphonamides as Antibacterial Agents.

BACKGROUND: Infection is a global threat to human health, and there is an urgent need to develop new effective antibacterial drugs to treat bacterial infections. OBJECTIVE: To study the antibacterial activity of piperazine substituted chalcone sulphonamides. MATERIALS AND METHODS: A series of novel piperazine substituted chalcone sulphonamides have been prepared, and in vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis and Escherichia coli strains were evaluated. RESULTS: The results showed that derivatives 6a, 6c and 6h displayed good antibacterial activity against Bacillus subtilis with MIC values of 4.0-8.0 mg/mL. CONCLUSION: Piperazine substituted chalcone sulphonamides may be used as potential antibacterial agents.

Synthesis and Biological Evaluation of Heterocyclic Substituted Bis(indolyl)methanes.

BACKGROUND: Bis(indolyl)methane derivatives are widely found in nature with a broad range of biological and pharmacological activities. The development of techniques for the synthesis and functionalization of bis(indolyl)methanes have attracted more and more attention in recent years. OBJECTIVE: To study the synthesis and biological activity of heterocyclic substituted bis(indolyl)methanes. MATERIALS AND METHODS: A series of heterocyclic substituted bis(indolyl)methanes (3a-3p) have been prepared by condensation reaction of indole and heterocyclic aldehydes catalyzed by boron trifluoride etherate with high yields. Preliminary in vitro anti-inflammatory in lipopolysaccharide (LPS)-stimulated RAW-264.7 macrophages and cytotoxic activity against human tumor cell lines (A549, Hela and SGC7901) by MTT assay were tested. RESULTS: The result indicated that heterocyclic substituted bis(indolyl)methanes showed good antiinflammatory and selective cytotoxic activity. Especially, compounds 3o, 3p and 3q displayed similar inhibitory effect on the generation of NO to positive control dexamethasone, and compound 3q displayed similar selective cytotoxic activity to 5-FU. CONCLUSION: Heterocyclic substituted bis(indolyl)methanes may be used as potential anti-inflammatory and anticancer leads.

Efficient Cu-catalyzed intramolecular O-arylation for synthesis of benzoxazoles in water.

An efficient method was developed for synthesis of benzoxazoles by Cu-catalyzed intramolecular O-arylation of o-halobenzanilides in water. This strategy provides several advantages, such as high yields, water as a green solvent and functional groups tolerance.

Synthesis of Scutellarein Derivatives with a Long Aliphatic Chain and Their Biological Evaluation against Human Cancer Cells.

Scutellarin is the major active flavonoid extracted from the traditional Chinese herbal medicine Erigeron breviscapus (Vant.) Hand-Mazz., which is widely used in China. Recently, accumulating evidence has highlighted the potential role of scutellarin and its main metabolite scutellarein in the treatment of cancer. To explore novel anticancer agents with high efficiency, a series of new scutellarein derivatives with a long aliphatic chain were synthesized, and the antiproliferative activities against Jurkat, HCT-116 and MDA-MB-231 cancer cell lines were assessed. Among them, compound 6a exhibited the strongest antiproliferative effects on Jurkat (IC50 = 1.80 µM), HCT-116 (IC50 = 11.50 µM) and MDA-MB-231 (IC50 = 53.91 µM). In particular, 6a even showed stronger antiproliferative effects than the positive control NaAsO2 on Jurkat and HCT-116 cell lines. The results showed that a proper long aliphatic chain enhanced the antiproliferative activity of scutellarein.