A survey on pupae parasitoid species of Dendrolimushoui (Lajonquiere) (Lepidoptera, Lasiocampidae) in China.

Cryptomeriajaponicavar.sinensis Miquel in south China is currently overwhelmingly infested by a native caterpillar species, Dendrolimushoui (Lepidoptera), which is causing severe economic losses and ecological disasters in both planted and natural forests. Our results include report of five parasitoid species and eight parasitoid flies within D.houi and a dominant endoparasitoid species Kriechbaumerelladendrolimi, which attacks pupae of D.houi with a high parasitism rate. This result might be helpful to improve better identification and application in the future for potential biological control of D.houi in the forests of east Asia.

Luteolin from Flos Chrysanthemi and its derivatives: New small molecule Bcl-2 protein inhibitors.

Over-expression of the Bcl-2 anti-apoptotic proteins is closely related to tumorigenesis and associated with drug resistance. Here we report that luteolin, a main substance found in Flos Chrysanthemi, directly binds to and shows inhibitory activity against the Bcl-2 protein. We studied the binding mode of luteolin and its derivatives with target proteins, their structure-activity relationship, and their effect on the human leukemia cell line HL-60. The results suggest that luteolin and its derivatives with a benzyl group introduced to the B ring, are new small molecule Bcl-2 protein inhibitors, and their anti-tumor activity is likely related to their effect on the Bcl-2 protein.

Synthesis and biological evaluation of 1-benzylidene-3,4-dihydronaphthalen-2-one as a new class of microtubule-targeting agents.

A series of 1-benzylidene-3,4-dihydronaphthalen-2-one derivatives were designed and synthesized, and their biological activities in vitro and in vivo were evaluated. The results showed a number of the title compounds exhibiting potent nanomolar activity in several human cancer cell lines. Of these, compound 22b showed the strongest inhibitory activity against human CEM, MDA-MBA-435, and K562 cells (IC(50) = 1 nM), displayed in vitro inhibition of tubulin polymerization (IC(50) = 3.93 µM), and significantly induced cell cycle arrest in G2/M phase. In addition, compound 22b could inhibit the tumor growth in colon nude mouse xenograft tumor model significantly and seemed safer than CA-4 when achieving a similar tumor suppression. This study provided a new molecular scaffold for the further development of antitumor agents that target tubulin.

Ethyl 5-(4-amino-phen-yl)isoxazole-3-carboxyl-ate.

The asymmetric unit of the title compound, C(12)H(12)N(2)O(3), contains two mol-ecules in which the benzene and isoxazole rings are almost coplanar, the dihedral angles between their mean planes being 1.76 (9) and 5.85 (8)°. The two mol-ecules inter-act with each other via N-H⋯N and N-H⋯O hydrogen bonds, which link the mol-ecules into layers parallel to the ac plane. The layers stack in a parallel mode with an inter-layer distance of 3.36 (7) Å.

Synthesis and biological evaluation of 1-phenyl-1,2,3,4-dihydroisoquinoline compounds as tubulin polymerization inhibitors.

A series of 1-phenyl-3,4-dihydroisoquinoline derivatives and several 1-phenyl-1,2,3,4-tetrahydroisoquinoline, 1-phenyl-isoquinoline analogues were synthesized, and their cytotoxicity and tubulin polymerization inhibitory activity were evaluated. The 1-phenyl-3,4-dihydroisoquinoline compounds were found to be potential tubulin polymerization inhibitors. Compound 5n, bearing a 3'-OH and 4'-OCH(3) substituted 1-phenyl B-ring, was shown to confer optimal bioactivity. The single-crystal structure of 5n was further determined by X-ray diffraction, and the binding mode of 5n to tubulin was obtained by molecular docking, which can explain the structure-activity relationships. The studies presented here provide a new structural type for the development of novel antitumor agents.

Design, synthesis, and activity evaluation of broad-spectrum small-molecule inhibitors of anti-apoptotic Bcl-2 family proteins: characteristics of broad-spectrum protein binding and its effects on anti-tumor activity.

On the basis of the comparison of the structure of the Bim BH3: Bcl-x(L) complex and that of the ABT-737: Bcl-x(L) complex, a series of class A compounds were designed. These compounds had the basic skeleton of ABT-737 and the h2 residues of Bim BH3. These residues had shown themselves to be relevant to Bim BH3's broad-spectrum binding properties in saturation mutagenesis assays. Unlike ABT-737, which is a selective inhibitor of anti-apoptotic members of the Bcl-2 protein family, the class A compounds showed broad-spectrum binding activity to target proteins similar to those of Bim BH3 peptide. Then class B compounds were synthesized by modifying the structure of the most effective class A compound, A-4. Most of these class B compounds showed better binding affinity to the target proteins than the class A compounds had. They also showed themselves more effective than ABT-737 at inhibiting growth in multiple tumor cell lines known to express Bcl-x(L), Bcl-2, and Mcl-1 proteins at high levels. Compounds B-11 and B-12 had the strongest anti-tumor activity of any compounds we produced. This study suggests that it is feasible to design small-molecule inhibitors based on the structure of Bim BH3, which shows broad-spectrum binding to Bcl-x(L), Bcl-2, and Mcl-1 proteins. Our results also suggest that the broad-spectrum properties of small-molecule inhibitors binding to target proteins play a critical role in inhibiting the growth of many tumor cells. Finally, our study provides a series of lead compounds that merit further research into anti-cancer therapeutics.

Imidazolone-amide bridges and their effects on tubulin polymerization in cis-locked vinylogous combretastatin-A4 analogues: synthesis and biological evaluation.

A series of novel combretastatin-A4 analogues in which the cis-olefinic bridge is replaced by an imidazolone-amide were synthesized, and their cytotoxicity and tubulin-polymerization inhibitory activities were evaluated. These compounds appear to be potential tubulin-polymerization inhibitors. Compounds 10, 9b and 9c, bearing 3'-NH2-4'-OCH3, 4'-CH3 and 3'-CH3-substituted 1-phenyl B-ring, confer optimal bioactivity. The binding modes of these compounds to tubulin were obtained by molecular docking, which can explain the compounds' structure-activity relationship. The studies presented here provide a new structural type for the development of novel antitumor agents.

Transcriptional response of Candida albicans biofilms following exposure to 2-amino-nonyl-6-methoxyl-tetralin muriate.

AIM: To identify changes in the gene expression profile of Candida albicans (C albicans) biofilms following exposed to 2-amino-nonyl-6-methoxyl-tetralin muriate(10b) and clarify the mechanism of 10b against C albicans biofilms. METHODS: Anti-biofilm activity of 10b was assessed by tetrazolium (XTT) reduction assay and the action mechanism against biofilms was investigated by cDNA microarray analysis and real-time RT-PCR assay. RESULTS: Ten differentially expressed genes were directly linked to biofilm formation and filamentous or hyphal growth (eg, NRG1, ECE1 and CSA1). Decreased gene expression was involved in glycolysis (eg, HXK2 and PFK1) and antioxidant defense (eg, SOD5), while increased gene expression was associated with enzymes that specifically hydrolyzed beta-1,3 glucan (XOG1), and with lipid, fatty acid and sterol metabolism (eg, SLD1, ERG6 and ERG2). Functional analysis indicated that addition of anti-oxidant ascorbic acid reduced inhibitory efficiency of 10b on mature biofilm. CONCLUSION: Inhibition of 10b on biofilm formation possibly depends on impairing the ability of C albicans to change its morphology via altering the expression of biofilm formation genes. Mitochondrial aerobic respiration shift and endogenous ROS augmentation might be a major contribution to reduce mature biofilm metabolic activity. The data may be useful for the development of new strategies to reduce the incidence of device-associated infections.

Design and synthesis of novel pyrazino[2,1-a]isoquinolin derivatives with potent antifungal activity.

A series of novel pyrazino[2,1-a]isoquinolin compounds were designed, synthesized, and their antifungal activities in vitro were evaluated. The results showed that all of the title compounds exhibited antifungal activities. Most of them exhibited stronger antifungal activities than the lead compounds; compound 7c is more potent than fluconazole against two of the three tested fungal strains. The studies presented here provide a new structural type for the development of novel antifungal agents.

2-Amino-nonyl-6-methoxyl-tetralin muriate inhibits sterol C-14 reductase in the ergosterol biosynthetic pathway.

AIM: To investigate the action mechanism of a novel chemical structural aminotetralin derivate, 2-Amino-Nonyl-6-Methoxyl-Tetralin Muriate (10b), against Candida albicans (C albicans) in the ergosterol biosynthetic pathway. METHODS: Antifungal susceptibility test of 10b was carried out using broth microdilution method, the action mechanism of 10b against C albicans was investigated by GC-MS spectrometry and real-time RT-PCR assay, and cytotoxicity of 10b in vitro was assessed by MTS/PMS reduction assay. RESULTS: 10b reduced the ergosterol content markedly, and the 50% ergosterol content inhibitory concentration (ECIC(50) value) was 0.08 microg/mL. Although the sterol composition of 10b-grown cells was completely identical with that of erg24 strain, the content of ergosta-8,14,22-trienol in 10b-grown cells was much higher than that in erg24 strain. Real-time RT-PCR assay revealed a global upregulation of sterol metabolism genes. In addition, the 50% inhibitory concentration (IC(50) value) of 10b was 11.30 microg/mL for murine embryonic fibroblasts and 35.70 microg/mL for human normal liver cells. CONCLUSION: 10b possessed a mode of action different from that of azoles and morpholines, whose targets were sterol C-14 reductase (encoded by ERG24 gene) and sterol C-5 desaturase (encoded by ERG3) related enzyme. Although 10b seemed to reduce MTS/PMS reduction in a dose dependent manner, IC(50) value for mammalian cells was much higher than 50% minimum inhibitory concentration (MIC(50)) value for C albicans. This indicates that the formulation is preliminarily safe and warrants further study for possible human applications.

[Nandeshi: a powerful inhibitor of human acrosin activity].

OBJECTIVE: To evaluate the inhibitory effect of Nandeshi, an acrosin inhibitor, on human acrosin activity. METHODS: We collected sperm samples from 10 healthy fertile men and cultured them with Nandeshi at 30 degrees C for 5 minutes at the concentrations of 0. 100, 0.120, 0.144, 0.173, 0.207, 0.249, 0.299, 0.358 and 0.430 mmol/L, with the controls treated with a well-known acrosin inhibitor N-alpha-p-tosyl-L-lysine chloromethylketone (TLCK) at 150.0, 189.8, 213.6, 240.3, 270.3, 304.1 and 342.1 mmol/L. Then we determined the residual activity of human acrosin by improved Kennedy assay. RESULTS: The residual activity of acrosin was negatively correlated with the Nandeshi concentration, and Nandeshi exhibited an inhibition rate about 800 times that of TLCK. CONCLUSION: Nandeshi has a powerful inhibitory effect on human acrosin, and improved Kennedy assay is a simple, practical and highly sensitive technique for the detection of human acrosin activity.

Construction of a three-dimensional pharmacophore for Bcl-2 inhibitors by flexible docking and the multiple copy simultaneous search method.

B-Cell lymphoma-2 (Bcl-2) protein is a new promising target for anticancer drugs. A number of anticancer Bcl-2 inhibitors with diverse chemical structures have been discovered in recent years. In this paper, the flexible docking was performed to determine the binding modes of the representative inhibitors from different structural types. Subsequently, the binding modes of inhibitor were used to construct a primary three- dimensional (3D) pharmacophore model. It proved that this model can effectively disrupt the binding of the BH3 domain of proapoptotic Bcl-2 family members to Bcl-2, and match the structural requirement of a new type of Bcl-2 inhibitors. However, these distances between pharmacophoric points are not optimal due to the fact that not all of individual functional groups are located in the ideal position when inhibitors bind to its receptor. In this paper, we proposed a new idea to improve the quality of the pharmacophore model: the multiple copy simultaneous search (MCSS) method was performed to determine the energetically favorable distribution of functional groups with similar features to these pharmacophoric points in the active site of Bcl-2 first. Then their most energetically favorable minima in the positions near the pharmacophoric points were used to optimize the distances between pharmacophoric points. By examining the binding modes of several inhibitors from the same structural type, it was found that the more potent the inhibitor was, the closer it was to the optimized distances between pharmacophoric points. The optimized 3D pharmacophore model obtained in this paper may provide a good starting point for further rational design of Bcl-2 inhibitors.

[Synthesis and antifungal activity of 1-(1,2,4-triazolyl-1H-1-yl)-2-(2,4-diflurophenyl)-3-(4-substituted benzyl-1-piperazinyl)-2-propanols].

AIM: A series of triazole antifungals were synthesized to search for novel triazole antifungals with more potent activity, less toxicity and broader spectrum. METHODS: Nineteen 1-(1,2,4-triazolyl-1H-1-yl)-2-(2,4-diflurophenyl)-3-(4-substituted benzyl-1-piperazinyl)-2-propanols were designed and synthesized, on basis of the three dimensional structure of P450 cytochrome 14 alpha-sterol demethylase (CYP51) and their antifungal activities were also evaluated. RESULTS: All the title compounds were first reported. Results of preliminary biological tests showed that most of the title compounds exhibited high activity against the eight common pathogenic fungi and the activities against deep fungi were higher than that against shallow fungi. CONCLUSION: Most of the title compounds showed higher antifungal activities than Fluconazole and Terbinafine. Compound VIII-1, 10, 12, 17 showed best antifungal activity with broad antifungal spectrum and were chosen for further development.

A Three-dimensional Model of Lanosterol 14alpha-demethylase of Candida albicans.

The three-dimensional structure of lanosterol 14alpha demethylase (P450(14DM), P450(51() of Candida albicans was modeled based on crystallographic coordinates of four prokaryotic cytochrome P450(S): P450BM3, P450cam, P450terp and P450eryF. The sequence of P450(51) was aligned to those of known proteins using a knowledge-based alignment method. The main chain coordinates of the structurally conserved regions (SCRs)) were transferred directly from the corresponding coordinates of P450BM3. The side chain conformations of SCRs) were determined based on the equivalent residues of four crystal structures which had the highest homologous scores. The model was then refined using molecular mechanics and molecular dynamics.The rationale of the resulting model were validated by Ramachandran plot,Profile-3K and hydropathy plot analysis. The structure-functionally important residues, such as the heme binding residues, the residues interacting with redox-partner protein and/or involved in electron transfer, the residues lining substrate access channel and the substrate binding residues, were identified from the model. These residues are candidates for further site-directed mutagensis and site-specific antipeptide antibody binding experiments.

Comparative Studies on Crystal Structures of Four Members of Cytochrome P450 Superfamily.

Secondary and steric structures and hydropathy plots of the 4 crystals of P450cam, P450terp, P450eryF and P450BM3 were compared to illustrate the structural conservation of cytochrome P450 superfamily proteins. Although sequence identities of four P450s are generally low (19%-26%), their topology is quite similar. All four structures have 13 alpha-helices and beta1-beta4 sheets in common. Four crystal structures were superimpossed by root-mean-square (RMS) fit of the prophyrin ring carbon atoms of prosthetic group heme to obtain the structure-based sequence alignment of four proteins. The RMS deviations of Calpha distance of each motifs were analyzed by hierarchical cluster analysis. The structural subsets were divided into four categories of structural conservation: the most conserved region, the less conserved region, the less variable region and the variable region. The first two groups (56.9 percentage of the aligned positions that have no gaps) include all the interior structures and active site residues. All four P450 proteins have the common hydrophobic and hydrophilic segments by hydropathy plots analyses. All the comparison results of P450 protein crystal structures provided the basis for structure-based sequence alignment of cytochrome P450 proteins.