Résumé
Pyrrole [1,2-α] indole is a novel fused heterocyclic skeleton, which is also the basic structural unit and synthetic intermediate of many natural active products and drugs. Pyrrole [1,2-α] indole heterocyclic derivatives have attracted much attention in organic synthesis and medicinal chemistry because of their extensive and marked biological activities. Plant extracts have always been an important source of active compounds. At present, the alkaloids based on the pyrrole [1,2-α] indole heterocyclic structure discovered and isolated from plant extracts include isatisine, isoborreverine, flinderoles, polyavolensin and yuremamine. This paper reviews the research progress on the biological activity of pyrrole [1,2-α] indole heterocyclic derivatives and has found that pyrrole [1,2-α] indole heterocyclic derivatives have a good development prospect in screening active compounds and developing candidate drugs.
Résumé
Benzazepine is a kind of fused ring structure, which is composed of nitrogen-containing seven-membered ring and benzene ring. The introduction of benzazepine scaffolds into compounds can not only adjust the physicochemical properties, maintain or enhance the biological activities of the compounds, but also improve the pharmacokinetic properties, increase the brain permeability, and reduce the toxicity of hERG of the compounds, which is one of the privileged scaffolds for rational design and structural optimization of drug molecules. Benzazepine scaffolds can be constructed by different synthetic methods such as Dickmann condensation reaction, Mitsunobu reaction, Pictet-Spengler reaction, CMD reaction, multicomponent reactions (MCRs), metal catalysis reactions and asymmetric catalysis etc., which play an important role in enriching the structure diversity of drug molecules.
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Natural products and their derivatives are important components of anti-tumor drugs. Currently, anti-tumor drugs derived from natural products which are in clinical practice are mainly conventional cytotoxic or molecularly targeted drugs. Their application is limited by drug-related side effects and drug resistance. Recent studies have shown that anti-tumor natural products often act on multiple targets in tumor cells and in turn interfere with multiple processes in tumorigenesis and development. As tumor is a systemic disease induced by multiple factors, multi-targeted natural products possess unique potential in tumor therapy. However, the targets and mechanisms of the discovered multi-targeted antitumor natural products remain elusive, which limits their further development and application. This review summarized the research progress in the mechanism of action, target identification, and structure optimization of multi-targeted anti-tumor natural products exemplified by a few typical compounds. The research and development of these agents have also been proposed.
Résumé
Most peptides have high binding affinity and good selectivity for endogenous receptors and are good lead compounds to develop into drugs. Many approved drugs are derived from the structural optimization of peptide molecules, such as the antihypertensive drug captopril and the anti-hepatitis C drug telaprevir. At present, the main problems in the development of peptide drugs include poor stability, short half-life, and high plasma clearance rate; lack of oral availability and poor patient compliance, a complex production process, and high production cost. Therefore, rational modification of peptides can not only reduce the production cost, but also improve the druggability of the peptides. Here we review structural modification strategies for peptides from the perspective of improving their physicochemical properties. These modification strategies are divided into two parts: one is modification of the peptide backbone, including unnatural amino acid modification, pseudopeptide strategy, inverse-peptide strategy, cyclization strategy, and terminal structure modification. Another is modification of the side chains of peptides, including fatty acid conjugation, polyethylene glycol conjugation, protein fusion strategy, and cholesterol conjugation.
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Objective To conduct simulation analysis on support performance of the stent by using finite element method, and optimize structure parameters of the stent by using Kriging surrogate model, so as to provide more scientific guidance for clinical treatment with design and development of the stent. Methods The contact model was established by penalty function method. The generalized variational principle was selected as theoretical basis of the numerical simulation, and the theory of Kriging surrogate model was used for finite element optimization on support stiffness of the stent, so as to study the effect from the number of circumferential support, the length of the support and the initial diameter on support performance of the stent. Results With the increase of the number of circumferential support or the length of the support, the support performance showed the decreasing tendency; with the increase of the initial diameter, the support performance showed the increasing tendency. From seven stents by using the theory of Kriging surrogate model, it was concluded that structural parameters of the optimal stent were: the number of circumferential support was six, the length of the support was 1.15 mm, and the initial diameter was 1.65 mm. Conclusions The numerical result agreed well with the experimental data and the error was smaller than 5%, and the error rate of experimental repeatability was within 0.5%, which verified effectiveness and rationality of the finite element analysis. The optimization of support performance provides an important reference for design and exploration of new magnesium alloy stent.
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Objective To study the interaction mechanism of anti-cancer drug docetaxel (DTX) andβ-tubulin, to determine the binding sites and the involved amino acids between the β-tubulin and docetaxel, and to analyze the dynamic combination process. Methods The docking binding energy and interaction sites of DTX molecules withβ-tubulin on the potential energy surface were calculated by molecular docking method. The dynamic interaction process of the low binding energy DTX with β-tubulin was simulated by molecular dynamics method. Results The results of molecular docking showed that there are three interaction sites, including N1, N2 and N3, between DTX and β-tubulin. The DTX molecules with structure of No.1, 2 and 4, which have excellent docking energy, were chose for molecular dynamics simulation. As a result, the dynamic change processes of the system complexes from non-equilibrium to equilibrium were obtained. The simulation results showed that the hydrogen bonds formed by the DTX with structure No.1 were significantly higher than those with structures No. 2 and 4. The solvent accessibility surface area of the DTX with structures No.1, 2 and 4 was higher than that of paclitaxel. Conclusion The model of DTX binding toβ-tubulin was established, which could provide theoretical guidance for the design and development of novel paclitaxel anticancer drugs.
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Chinese materia medica (CMM) is the product of long-term practice of clinical traditional Chinese medicine (TCM), and it has the characteristics of overall effect of the multi-component and multilink multiple targets. Because of the complexity of CMM, it has not yet formed systematic and the scientific method for the TCM research, which seriously restricts the development of modernization of CMM. Under the guidance of TCM theory, we explore the study on the new mode of CMM whose components are divided into the functional units by the CMM research foundation of material basis, pharmacological mechanism, the structure optimization, and new idea on the CMM quality control based on composition structure theory and in vivo pharmacokinetic as well.