Synthesis and Biological Evaluation of 2-(3‘,4‘,5‘-Trimethoxybenzoyl)-3-Amino 5-Aryl Thiophenes as a New Class of Tubulin Inhibitors

Repurposing N-hydroxy thienopyrimidine-2,4-diones (HtPD) as inhibitors of human cytomegalovirus pUL89 endonuclease: Synthesis and biological characterization

The terminase complex of human cytomegalovirus (HCMV) is required for viral genome packaging and cleavage. Critical to the terminase functions is a metal-dependent endonuclease at the C-terminus of pUL89 (pUL89-C). We have previously reported metal-chelating N-hydroxy thienopyrimidine-2,4-diones (HtPD) as inhibitors of human immunodeficiency virus 1 (HIV-1) RNase H. In the current work, we have synthesized new analogs and resynthesized known analogs of two isomeric HtPD subtypes, anti-HtPD (13), and syn-HtPD (14), and characterized them as inhibitors of pUL89-C. Remarkably, the vast majority of analogs strongly inhibited pUL89-C in the biochemical endonuclease assay, with IC50 values in the nM range. In the cell-based antiviral assay, a few analogs inhibited HCMV in low μM concentrations. Selected analogs were further characterized in a biophysical thermal shift assay (TSA) and in silico molecular docking, and the results support pUL89-C as the protein target of these inhibitors. Collectively, the biochemical, antiviral, biophysical, and in silico data reported herein indicate that the isomeric HtPD chemotypes 13-14 can serve as valuable chemical platforms for designing improved inhibitors of HCMV pUL89-C.

Synthesis and characterization of novel combretastatin analogues of 1,1-diaryl vinyl sulfones, with antiproliferative potential via in-silico and in-vitro studies

Novel 1,1-diaryl vinyl-sulfones analogues of combretastatin CA-4 were synthesized via Suzuki-Miyaura coupling method and screened for in-vitro antiproliferative activity against four human cancer cell lines: MDA-MB 231(breast cancer), HeLa (cervical cancer), A549 (lung cancer), and IMR-32 (neuroblast cancer), along with a normal cell line HEK-293 (human embryonic kidney cell) by employing 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The compounds synthesised had better cytotoxicity against the A549 and IMR-32 cell lines compared to HeLa and MDA-MB-231 cell lines. The synthesized compounds also showed significant activity on MDA-MB-231 cancer cell line with IC₅₀ of 9.85-23.94 µM, and on HeLa cancer cell line with IC₅₀ of 8.39-11.70 µM relative to doxorubicin having IC₅₀ values 0.89 and 1.68 µM respectively for MDA-MB-231 and HeLa cell lines. All the synthesized compounds were not toxic to the growth of normal cells, HEK-293. They appear to have a higher binding affinity for the target protein, tubulin, PDB ID = 5LYJ (beta chain), relative to the reference compounds, CA4 (- 7.1 kcal/mol) and doxorubicin (- 7.2 kcal/mol) except for 4E, 4M, 4N and 4O. The high binding affinity for beta-tubulin did not translate into enhanced cytotoxicity but the compounds (4G, 4I, 4J, 4M, 4N, and 4R, all having halogen substituents) that have a higher cell permeability (as predicted in-silico) demonstrated an optimum cytotoxicity against the tested cell lines in an almost uniform manner for all tested cell lines. The in-silico study provided insight into the role that cell permeability plays in enhancing the cytotoxicity of this class of compounds and as potential antiproliferative agents.

Expedition of sulfur-containing heterocyclic derivatives as cytotoxic agents in medicinal chemistry: A decade update

This review article proposes a comprehensive report of the design strategies engaged in the development of various sulfur-bearing cytotoxic agents. The outcomes of various studies depict that the sulfur heterocyclic framework is a fundamental structure in diverse synthetic analogs representing a myriad scope of therapeutic activities. A number of five-, six- and seven-membered sulfur-containing heterocyclic scaffolds, such as thiazoles, thiadiazoles, thiazolidinediones, thiophenes, thiopyrans, benzothiazoles, benzothiophenes, thienopyrimidines, simple and modified phenothiazines, and thiazepines have been discussed. The subsequent studies of the derivatives unveiled their cytotoxic effects through multiple mechanisms (viz. inhibition of tyrosine kinases, topoisomerase I and II, tubulin, COX, DNA synthesis, and PI3K/Akt and Raf/MEK/ERK signaling pathways), and several others. Thus, our concise illustration explains the design strategy and anticancer potential of these five- and six-membered sulfur-containing heterocyclic molecules along with a brief outline on seven-membered sulfur heterocycles. The thorough assessment of antiproliferative activities with the reference drug allows a proficient assessment of the structure-activity relationships (SARs) of the diversely synthesized molecules of the series.

Strategic design and synthesis of star-shaped organic linkers for mesoporous MOFs

In the process of designing new MOFs with the aim of having a specific morphology, the shape of the linkers and the choice of coordinating metals have major importance. In this study, the aim to create novel hnb non-interpenetrating MOFs led us to choose tritopic linkers. Novel star-shaped molecules, presenting trigonal geometry and based on aromatic rings, were synthesized. For more convenient synthesis of the library, C-C coupling reactions via a direct arylation methodology were performed. This new synthetic tool, together with the idea of a molecule as a modular combination of smaller building blocks, made possible the fast, cheap and reproducible production of this class of compounds and also its scale-up. With one of the compounds, a MOF was synthesized and characterised via its specific surface area, which varies between 1681 and 3770 m2 g-1.

Deciphering the key heterocyclic scaffolds in targeting microtubules, kinases and carbonic anhydrases for cancer drug development

Heterocyclic scaffolds are widely utilized for drug design by taking into account the molecular structure of therapeutic targets that are related to a broad spectrum of ailments, including tumors. Such compounds display various covalent and non-covalent interactions with the specific residues of the target proteins while causing their inhibition. There is a substantial number of heterocyclic compounds approved for cancer treatment, and these compounds function by interacting with different therapeutic targets involved in tumorogenesis. In this review, we trace and emphasize the privileged heterocyclic pharmacophores that have immense potency against several essential chemotherapeutic tumor targets: microtubules, kinases and carbonic anhydrases. Potent compounds currently undergoing pre-clinical and clinical studies have also been assessed for ascertaining the effective class of chemical scaffolds that have significant therapeutic potential against multiple malignancies. In addition, we also describe briefly the role of heterocyclic compounds in various chemotherapy regimens. The optimized molecular hybridization of delineated motifs may result in the discovery of more active anticancer therapeutics and circumvent the development of resistance by specific targets in the future.

Synthesis and Biological Evaluation of New Antitubulin Agents Containing 2-(3',4',5'-trimethoxyanilino)-3,6-disubstituted-4,5,6,7-tetrahydrothieno[2,3-c]pyridine Scaffold

Two novel series of compounds based on the 4,5,6,7-tetrahydrothieno[2,3-c]pyridine and 4,5,6,7-tetrahydrobenzo[b]thiophene molecular skeleton, characterized by the presence of a 3′,4′,5′-trimethoxyanilino moiety and a cyano or an alkoxycarbonyl group at its 2- or 3-position, respectively, were designed, synthesized, and evaluated for antiproliferative activity on a panel of cancer cell lines and for selected highly active compounds, inhibition of tubulin polymerization, and cell cycle effects. We have identified the 2-(3′,4′,5′-trimethoxyanilino)-3-cyano-6-methoxycarbonyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine derivative 3a and its 6-ethoxycarbonyl homologue 3b as new antiproliferative agents that inhibit cancer cell growth with IC₅₀ values ranging from 1.1 to 4.7 μM against a panel of three cancer cell lines. Their interaction with tubulin at micromolar levels leads to the accumulation of cells in the G2/M phase of the cell cycle and to an apoptotic cell death. The cell apoptosis study found that compounds 3a and 3b were very effective in the induction of apoptosis in a dose-dependent manner. These two derivatives did not induce cell death in normal human peripheral blood mononuclear cells, suggesting that they may be selective against cancer cells. Molecular docking studies confirmed that the inhibitory activity of these molecules on tubulin polymerization derived from binding to the colchicine site.

The study of antimicrobial, anti-cancer, anti-inflammatory and α-glucosidase inhibitory activities of Nigronapthaphenyl, isolated from an extract of Nigrospora sphaerica

A new compound, nigronapthaphenyl, was extracted from the endophytic fungus Nigrospora sphaerica isolated from a mangrove plant Bruguiera gymnorrhyza. The structure of the compound was elucidated by analysis of 1D and 2D NMR spectra and mass spectrometric data. It was tested in vitro for its antimicrobial activity, cytotoxicity, anti-inflammatory activity and for its ability to inhibit α-glucosidase. Nigronapthaphenyl showed antibacterial activities against Bacillus subtilis TISTR 088 and Bacillus cereus TISTR 688 with MIC values of 4 and 2 μg/mL respectively. Cytotoxicity against colon cancer cell line HCT 116 was found to be an IC50 value of 9.62 ± 0.5 μM . This further showed potential anti-inflammatory activity amounting to an IC50 of 6.2 ± 0.5 μM and also α-glucosidase inhibitory activity, with an IC50 value of 6.9 ± 0.5 μM.

2-Alkoxycarbonyl-3-arylamino-5-substituted thiophenes as a novel class of antimicrotubule agents: Design, synthesis, cell growth and tubulin polymerization inhibition

Microtubules are recognized as crucial components of the mitotic spindle during cell division, and, for this reason, the microtubule system is an attractive target for the development of anticancer agents. Continuing our search strategy for novel tubulin targeting-compounds, a new series of 2-alkoxycarbonyl-3-(3',4',5'-trimethoxyanilino)-5-aryl/heteroarylthiophene derivatives was designed, synthesized and demonstrated to act as tubulin polymerization inhibitors at the colchicine site. A structure-activity relationship study on the phenyl at the 5-position of the thiophene ring was performed by introducing a variety of substituents containing electron-releasing and electron-withdrawing groups, with the 2-alkoxycarbonyl-3-(3',4',5'-trimethoxyanilino)thiophene scaffold being the minimum structural requirement for activity. Of the tested compounds, derivatives 4a, 4c, 4i and 4k possessed the highest overall potency and displayed high antiproliferative activities at submicromolar concentrations, with IC₅₀ values ranging from 0.13 to 0.84 μM against four different cancer cell lines. Three agents (4a, 4c and 4i) in the present series had similar effects, and these were comparable to those of the reference compound combretastatin A-4 (CA-4) as inhibitors of tubulin assembly. The antitubulin effects correlated with the cytostatic activities and indicate that these compounds inhibit cell growth through inhibition of tubulin polymerization by binding at the colchicine site. Compound 4c, containing the 2'-thienyl ring at the 5-position of the 2-methoxycarbonyl-3-(3',4',5'-trimethoxyanilino)thiophene scaffold, exhibited substantial antiproliferative activity with a mean IC₅₀ value of 140 nM, inhibited tubulin polymerization with an IC₅₀ value of 1.2 μM, similar to that of CA-4 (IC₅₀: 1.1 μM), and induced apoptosis in HeLa cells.

MoO2Cl2 catalyzed efficient synthesis of functionalized 3,4-dihydropyrimidin-2(1H)-ones/thiones and polyhydroquinolines: recyclability, fluorescence and biological studies

MoO₂Cl₂ catalyzed Biginelli, Hantzsch reactions exploring spectroscopic and biological properties of novel compounds.

Synthesis and Structure-Activity Relationship Study of 1-Phenyl-1-(quinazolin-4-yl)ethanols as Anticancer Agents

A quinazoline derivative PVHD121 (1a) was shown to have strong antiproliferative activity against various tumor-derived cell lines, including A549 (lung), NCI-H460 (lung), HCT116 (colon), MCF7 (breast), PC3 (prostate), and HeLa (cervical) cells with IC50 values from 0.1 to 0.3 μM. A structure-activity relationship (SAR) study at the 2- and 4-position of the quinazoline core lead to the discovery of more potent anticancer agents (14, 16, 17, 19, 24, and 31). The results of an in vitro tubulin polymerization assay and fluorescent-based colchicine site competition assay with purified tubulin indicated that 1a inhibits tubulin polymerization by binding to the colchicine site.

Synthesis of 2,5-asymmetrically substituted 3,4-diaminothieno[2,3-b]thiophenes by domino reaction

A convenient one pot synthesis of 2,5-asymmetrically substituted thieno[2,3-b]thiophenes is developed. The method is based on consecutive domino reactions (SN2 reaction → Thorpe-Ziegler reaction) using malononitrile and carbon disulfide as starting materials with the generation of potassium 2,2-dicyanoethene-1,1-bis(thiolate) in a solution. The high yield of the target thienothiophenes was achieved using the Ziegler dilution effect.

Indole molecules as inhibitors of tubulin polymerization: potential new anticancer agents

Agents that interfere with tubulin function have a broad anti-tumor spectrum and they represent one of the most significant classes of anticancer agents. In the past few years, several small synthetic molecules that have an indole nucleus as a core structure have been identified as tubulin inhibitors. Among these, several aroylindoles, arylthioindoles, diarylindoles and indolylglyoxyamides have shown good inhibition towards the tubulin polymerization. This article reviews the synthesis, biological activities and SARs of these main classes of indoles. Brief mention has also been made about the fused indole analogs as tubulin inhibitors.

Synthesis of macrocyclic bisbibenzyl derivatives and their anticancer effects as anti-tubulin agents

Based on the core skeleton of the total synthesized bisbibenzyl marchantin C, riccardin D and plagiochin E, a series of brominated and aminomethylated derivatives of above three bisbibenzyls have been synthesized and their cytotoxic activity against KB, MCF-7 and PC3 cell lines has been preliminary evaluated. The bio-test results revealed that the brominated derivatives 21, 22, 24, 25 and 28 exhibited excellent antiproliferative activity, with IC(50) value lower than their parent compounds. As a most potent microtubule depolymerization agent, compound 28 was found to arrest cells at the G(2)/M phase of the cell cycle as determined by the flow cytometry assay in PC3 cell line. The remarkable biological profile and novel structure of these bisbibenzyl derivatives make them possible as promising candidates for clinical development as chemotherapeutic agents.

3-Aryl-2-[1H-benzotriazol-1-yl]acrylonitriles: a novel class of potent tubulin inhibitors

During a screening for compounds that could act against Mycobacterium tuberculosis, a series of new cellular antiproliferative agents was identified. The most cytotoxic molecules were evaluated against a panel of human cell lines derived from hematological and solid human tumors. In particular, (E)-2-(1H-benzo[d] [1,2,3]triazol-1-yl)-3-(4-methoxyphenyl)acrylonitrile (1) was found to be of a potency comparable to etoposide and greater than 6-mercaptopurine in all cell lines tested. Accordingly, a synthesis of a new series of (E)-2-(5,6-dichloro-1H-benzo[d] [1,2,3]triazol-1-yl)-3-(4-R-phenyl)acrylonitriles was conducted in order to extend the studies of structure-activity relationship (SAR) for this class of molecules. With the aim to evaluate if 3-aryl-2-[1H-benzotriazol-1-yl]acrylonitriles were able to act like tubulin binding agents, the effects on cell cycle distribution of the most active compounds (1, 2a, 3 and 4) were analyzed in K562 cells. A detailed molecular modeling study of the putative binding mode of this series of compounds on tubulin is also reported.

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.

Use of 2-aminoprop-1-ene-1,1,3-tricarbonitrile for the synthesis of tetrahydronaphthalene, hexahydroisoquinoline and hexahydrocinnoline derivatives with potential antitumor activities

The aim of the work was to synthesize heterocyclic compounds from 2-aminoprop-1-ene-1,1,3-tricarbonitrile and to study their antitumor activities. The title reagent reacted with cyclohexanone to give the ethylidene derivative 2. The reactivity of the latter product towards different chemical reagents was studied to give tetrahydronaphthalene, hexahydroisoquinoline and hexahydrocinnoline derivatives. The newly synthesized products were screened as antitumor agents on the in vitro growth of three human tumor cell lines representing different tumor types, namely, breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS cancer (SF-268). It was found that some of these compounds showed inhibitory effects on the three cell lines, indicating their potential use in the development of oncology products.

COMPARATIVE MOLECULAR FIELD ANALYSIS OF ANTI-TUBULIN AGENTS WITH INDOLE RING BINDING AT THE COLCHICINE BINDING SITE

A 3D-QSAR study using comparative molecular field analysis (CoMFA) was carried out on anti-tubulin agents with indole as a nucleus core. The structures of the compounds were obtained using docking calculations, and were then subjected to alignment procedures. CoMFA calculations for the 42 ligands that were examined as the training set gave a q2 value of 0.623 in correlation with experimental IC50 values for the inhibition of MKN-45 gastric cancer cells. Calculation for the test set of 17 ligands resulted in an r2 value of 0.714. The calculated results suggest that the R3 functional group site (see structure in Fig. 1) favored bulky groups while R1, R2, and R4 sites favored the opposite. At the R5 and R6 sites, parts of the region favored bulky groups while other parts favored the opposite. As for the electrostatic aspect, the R3 site was found to favor groups with a negative partial charge. At the R2 site, part of the region favored the group with a negative partial charge while other regions favored groups with a positive partial charge. The R4 and R5 sites favored groups with negative and positive partial charges, respectively, with a less favorable magnitude when compared with the R2 and R3 sites. The R1 and R6 sites did not exhibit significant electrostatic favor. Correlation of the results with IC50 values of ligands were analyzed and discussed.

How much binding affinity can be gained by filling a cavity?

Binding affinity optimization is critical during drug development. Here, we evaluate the thermodynamic consequences of filling a binding cavity with functionalities of increasing van der Waals radii (-H, -F, -Cl, and CH(3)) that improve the geometric fit without participating in hydrogen bonding or other specific interactions. We observe a binding affinity increase of two orders of magnitude. There appears to be three phases in the process. The first phase is associated with the formation of stable van der Waals interactions. This phase is characterized by a gain in binding enthalpy and a loss in binding entropy, attributed to a loss of conformational degrees of freedom. For the specific case presented in this article, the enthalpy gain amounts to -1.5 kcal/mol while the entropic losses amount to +0.9 kcal/mol resulting in a net 3.5-fold affinity gain. The second phase is characterized by simultaneous enthalpic and entropic gains. This phase improves the binding affinity 25-fold. The third phase represents the collapse of the trend and is triggered by the introduction of chemical functionalities larger than the binding cavity itself [CH(CH(3))(2)]. It is characterized by large enthalpy and affinity losses. The thermodynamic signatures associated with each phase provide guidelines for lead optimization.

2-Arylamino-4-amino-5-aroylthiazoles. "One-pot" synthesis and biological evaluation of a new class of inhibitors of tubulin polymerization

The essential role of microtubules in mitosis makes them a major target of compounds useful for cancer therapy. In our search for potent antitumor agents, a novel series of 2-anilino-4-amino-5-aroylthiazoles was synthesized and evaluated for antiproliferative activity, inhibition of tubulin polymerization, and cell cycle effects. SAR was elucidated with various substitutions on the phenylamino and aroyl moiety at the 2- and 5-positions, respectively, of the 4-aminothiazole skeleton. Tumor cell exposure to several of these compounds led to the arrest of HeLa cells in the G2/M phase of the cell cycle and induction of apoptosis.

Synthesis and structure-activity relationships of 1-benzyl-4,5,6-trimethoxyindoles as a novel class of potent antimitotic agents

A series of 1-benzyl-4,5,6-trimethoxyindoles was designed and prepared as a novel class of potent antimitotic agents acting through the colchicine binding site of tubulin. Compounds 10 and 11 showed excellent antiproliferative activity with mean IC(50) values of 26 and 27 nM, respectively, in a diverse set of human cancer lines from different organs, including a MDR+ line. They also displayed substantial antitubulin efficacy with IC(50) values of 3.5 and 2.6 muM, respectively, representing an improvement over colchicine (IC(50)=4.3 muM).

Discovery of 4-amino and 4-hydroxy-1-aroylindoles as potent tubulin polymerization inhibitors

1-Aroylindoline, 1-aroyl-1,2,3,4-tetrahydroquinoline, and 1-aroylindole derivatives were synthesized and evaluated for anticancer activity. The 4-amino and 4-hydroxy-1-aroylindoles 26 and 27 with IC 50 of 0.9 and 0.6 microM, respectively, exhibited antitubulin activity superior or comparable to that of colchicine and combretastatin A-4. They also showed antiproliferative activity with IC 50 of 0.3-5.4 nM in a set of human cancer cell lines.

Antimitotic activities of 2-phenylindole-3-carbaldehydes in human breast cancer cells

Small molecules such as indoles are attractive as inhibitors of tubulin polymerization. Thus a number of 2-phenylindole-3-carbaldehydes with lipophilic substituents in both aromatic rings was synthesized and evaluated for antitumor activity in MDA-MB 231 and MCF-7 breast cancer cells. Some 5-alkylindole derivatives with a 4-methoxy group in the 2-phenyl ring strongly inhibit the growth of breast cancer cells with IC(50) values of 5-20nM. Their action can be rationalized by the cell cycle arrest in G(2)/M phase due to the inhibition of tubulin polymerization.

A novel class of tubulin inhibitors that exhibit potent antiproliferation and in vitro vessel-disrupting activity

PURPOSE

Since anticancer agents that interfere with microtubule function are in widespread use and have a broad spectrum of activity against both hematological malignancies and solid tumors, there is an urgent need to develop novel tubulin inhibitors with broader activities and avoiding drug resistance.

METHODS AND RESULTS

In this study, we describe the characterization of select lead compounds from a novel class of indazole-based tubulin inhibitors. Three lead compounds, TH-337, TH-482 and TH-494, exhibit potent antiproliferative activity against cell lines derived from human pancreatic carcinoma, human breast adenocarcinoma and human colorectal adenocarcinoma cells. The three compounds were also tested for cytotoxicity against a panel of clinically relevant drug resistant cancer cell lines that either overexpress the drug resistance pumps MDR-1, MRP-1 and BCRP-1 or have altered Topoisomerase II activity. TH-482 and -494 retained cytotoxic activities against all of the resistant cell lines tested; however, TH-337 exhibited decreased cytotoxicity in the cell line overexpressing BCRP-1, indicating that TH-337 is a substrate of that pump. We show that TH-482's antiproliferative activity is due to cell cycle arrest at the G(2)/M phase. We demonstrate that TH-482 binds specifically to the colchicine site of tubulin and that it inhibits tubulin polymerization in vitro in a concentration-dependent manner. The in vitro anti-vascular activities of TH-482 were assessed using the HUVEC-C cell line. TH-482 inhibits in vitro neovessel formation and disrupts pre-established vessels using HUVEC-C cells. TH-482 also increases permeability of vascular endothelial cells in a concentration- and time-dependent manner.

CONCLUSIONS

TH-482 demonstrates potent in vitro efficacy as a novel tubulin-targeted anti-proliferative and anti-vascular agent and notably is more potent in antiproliferative assays than the benchmark compound combretastatin A-4. These results identify TH-482 as a potent tubulin inhibitor, and support the investigation of its in vivo efficacy and pharmacokinetic properties as the prototype of a new class of anti-tubulin agents.

Synthesis and antifungal activities of 5-(3,4,5-trimethoxyphenyl)-2-sulfonyl-1,3,4-thiadiazole and 5-(3,4,5-trimethoxyphenyl)-2-sulfonyl-1,3,4-oxadiazole derivatives

Starting from the key intermediate 5-(3,4,5-trimethoxyphenyl)-1,3,4-thiadiazole-2-thiol (4) or the oxadiazole analogue (5), the title compounds 9 and 10 are synthesized by a two-step process. Thioetherification reaction of 4 or 5 with an organic halide catalyzed by indium or indium tribromide first affords appropriate sulfide 7 or 8, which is then converted into title compounds 9 or 10 by hydrogen peroxide oxidation catalyzed by ammonium molybdate in ionic liquid [bmim]PF6. The structures are unequivocally confirmed by spectroscopic (IR, 1H and 13C NMR) data and elemental analyses. The structures of 8d and 10q are further established by X-ray crystallographic diffraction analysis. The compounds have been shown to be fungicidally active. Title compounds 10i and 10j can inhibit mycelia growth by approximately 50% (EC50) at 2.9-93.3 microg/mL in vitro against 10 kinds of fungi.