Design and synthesis of novel antifungal triazole derivatives with good activity and water solubility

In order to find novel antifungal agents with good activity and aqueous solubility,a series of SYN-2869 analogues containing a pyridine ring were synthesized and evaluated for their in vitro antifungal activity and water solubility.The results indicated that some compounds showed potent activity against six pathogenic fungi.In particular,the analogue 17a having an isobutyl substitution on the triazolone exhibited significant broad spectrum antifungal activity.In addition,the water solubility of compound 17a was sufficiently improved over SYN-2869.     

Design, synthesis, and evaluation of azepine-based cryptophycin mimetics

Cryptophycins, depsipeptides isolated from terrestrial blue-green algae, show potent activity against a variety of tumor cell lines. Given the potential of the cryptophycins for cancer therapy, we developed a new class of non-peptide peptidomimetic, designed to replace the 16-membered macrolide ring with a 7-membered azepine ring for attachment of the cryptophycin side chains with the required spatial orientation to mimic the conformation of the relevant region of the natural product. Monte Carlo conformational analysis revealed excellent overlay of the local minimum structural model 6 and X-ray structure of (+)-cryptophycin-3 (5). Starting from this structural model, we designed and synthesized compounds (+)-25, (+)-30, and (+)-34 as potential mimics of cryptophycins. Compounds (+)-25, (+)-30, and (+)-34 were tested for in vitro cytotoxicity against six human cancer cell lines. Although only modest activities were observed, these results suggested that a new series of bioactive cryptophycin analogues might be available by structural modification of the central ring system of the cryptophycins.     

Synthesis and bioactivity of novel pyrazole oxime derivatives containing oxazole ring

A series of novel pyrazole oxime derivatives containing oxazole ring were designed and synthesized. The title compounds were structurally confirmed by 1H NMR, 13C NMR spectra and elemental analyses. Preliminary bioassay results showed that some of the title compounds displayed promising fungicidal activity besides insecticidal and acaricidal activity. Particularly, compound 8c exhibited potent fungicidal activity against cucumber Pseudoperonospora cubensis beyond good insecticidal activity against Aphis craccivora and Nilaparvata lugens.     

Novel pyrrolo[2,3-d]pyrimidine derivatives: Design,synthesis, structure elucidation and in vitro anti-BVDV activity

The progression of drug resistance of viral infection justifies the discovering of new anti-viral agents. Thus, a novel series of pyrrolopyrimidine derivatives 5–7 and 9–18 were designed, synthesized and fully characterized by IR, mass spectroscopy, NMR, and elemental analysis. The structure of 4,6-dichloro-pyrrolo[2,3-d]pyrimidine 10 elucidated by single crystal X-ray diffraction. Herein, we reported the first pyrrolo[2,3-d]pyrimidine compounds with trichloromethane at position 2 of the pyrimidine ring. As initial biological activity screening, evaluation of the pyrrolo[2,3-d]pyrimidine compounds as anti-BVDV (Bovine Viral Diarrhea Virus) was examined. The compounds 11, 13, 16 and 17 exhibited excellent activity as a potent inhibitor against BVDV. Structure activity relationship showed that the pyrrolo[2,3-d]pyrimidine molecules presenting hydrogen atom or trichloromethyl group on C2 and chlorine, sulfur, pyrrolidine or methoxy groups on C4 of the pyrimidine ring showed high activity as anti-BVDV in comparison with the compounds which have Cl or CH₃ on C2 position.     

Design,synthesis and docking studies of new hydrazinyl-thiazole derivatives as anticancer and antimicrobial agents

Increase in the number of infections caused by pathogenic microbes in cancer patients has prompted the searcher to invest in the development of agents having dual anticancer and antimicrobial properties. The present study is concerned with synthesis and screening for anticancer and antimicrobial activity of a series of 5-hydrazinyl-2-(2-(1-(thien-2-yl)ethylidene)hydrazinyl)thiazole derivatives. The structure elucidation of the synthesized hydrazinyl thiazole derivatives was illustrated by spectroscopic and elemental analysis. All the newly synthesized compounds 5a-p were evaluated for in-vitro cytotoxic activity against breast carcinoma (MCF-7 cell line), hepatocellular carcinoma (HePG-2) and colorectal cancer (HCT-116) cell lines using MTT assay method. Compounds 5 g, 5h showed broad spectrum activity against three cancer cell lines with IC₅₀ ranged from 3.81 to 11.34 µM in compared to the reference drug Roscovitine (IC₅₀ = 9.32 to 13.82 µM), while compounds 5 l and 5 m were found to be more selective against HePG-2 and HCT-116 cell line (IC₅₀ = 9.29 and 8.93 µM respectively) and compound 5j was more selective against HePG-2 and MCF-7 cell lines (IC₅₀ = 6.73 and 10.87 µM respectively). The inhibitory activity of the most promising compounds was tested against the EGFR and ARO enzymes and were further tested for apoptosis and Annexin V/PI staining. The results of enzyme-based tests revealed that the tested compound 5j has a dual inhibitory effect on the EGFR and ARO enzymes with IC₅₀ = 82.8 and 98.6 nM respectively in compared to the reference drugs Erlotinib and Letrozole (IC₅₀ = 62.4 and 79 nM respectively). Furthermore, the majority of the tested hydrazinyl thiazole derivatives exhibited significant antimicrobial activity against the used pathogenic microbes species. Compounds 4b, 5h, 5j and 5 m exerted a good antibacterial and antifungal activity against all tested pathogenic microbes. Therefore, it was concluded that compounds 5 h, 5j and 5 m proved to possess dual anticancer and antimicrobial agent and may serves as a useful lead compounds in search for further modification or derivatization to give more potent and selective agents.     

In vitro biological studies of heteroleptic Ag(I) and Cu(I) unsymmetrical N,N′-diarylformamidine dithiocarbamate phosphine complexes; the effect of the metal center

A series of five dithiocarbamate and their respective Ag(I) and Cu(I) triphenylphosphine complexes of the general formula [Ag/Cu(PPh₃)₂L] were synthesized and characterized. The dithiocarbamate ligands were synthesized from formamidines with substituents in the 2 and/or 6 positions of the phenyl rings, intentionally keeping substituents on one ring different from those of the second phenyl ring while investigating the structure-activity relationship of Ag(I) and Cu(I) dithiocarbamate complexes. All Ag(I) and Cu(I) complexes with the general formula [Ag(PPh₃)₂L] (1–5) or [Cu(PPh₃)₂L] (6–10), displayed distorted tetrahedral geometry around the metal centers with coordination via two S atoms of the dithiocarbamate ligand and two P atoms from the PPh₃ units. Complexes 1–5 showed better inhibition values against Gram-positive, Staphylococcus aureus (methicillin resistant) and Staphylococcus aureus than the standard used, ciprofloxacin. Complexes 1 and 2 generally had good activity against all bacterial strains but were not active against Salmonella typhimurium. All Cu(I) complexes were either of low activity or inactive against all bacterial strains tested. Complex 2 was found to be more active with IC₅₀ values of 1.34 × 10⁻³ mM and 0.25 mM as agents for antioxidant activity against DPPH and NO free radical scavengers, respectively. The metal center played a vital role in their biological activity as the Ag(I) complexes displayed better antibacterial and antioxidant activity than Cu(I) complexes.     

Synthesis,antimicrobial and cytotoxic activity of novel azetidine-2-one derivatives of 1H-benzimidazole

A series of 1-methyl-N-[(substituted-phenylmethylidene)-1H-benzimidazol-2-amines (4a–4g) were prepared via the formation of 1-methyl-1H-benzimidazol-2-amine (3), which was prepared by the cycloaddition of o-phenylenediamine (1) with cyanogen bromide in the presence of aqueous base followed by N-methylation with methyl iodide in the presence of anhydrous potassium carbonate in dry acetonitrile. Moreover, the four-membered β-lactam ring was introduced by the cycloaddition of 4a–4g and chloroacetyl chloride in the presence of triethylamine catalyst to give 3-chloro-1-(1-methyl-1H-benzimidazol-2-yl)-(4′-substituted)-phenylazetidin-2-one 5a–5g. A total of 14 compounds were synthesized and characterized by IR, ¹H NMR, ¹³C NMR and Mass spectral technique, in addition they were evaluated for anti-bacterial and cytotoxic properties. Among the chemicals tested 4a, 4b, 5a, 5b, 5g exhibited good antibacterial activity and 5f, 5g shown good cytotoxic activity in vitro.     

Synthesis,bioactivity and preliminary mechanism of action of novel trifluoromethyl pyrimidine derivatives

In this study, a series of trifluoromethyl pyrimidine derivatives 5a-5v were designed and synthesized. All synthetic compounds were original. Bioassay results showed that some of the target compounds were proved to have higher antiviral and antifungal activities than those of commercial agents. Especially, EC₅₀ values of the curative activity of compound 5j and the protection activity of compound 5m were 126.4 and 103.4 µg/mL, respectively, which were lower than that of ningnanmycin. Microscale thermophoresis experiment proved that there was a good interaction between compound 5m and TMV-CP. Meanwhile, the antifungal activity results showed that compound 5u had a significant on in vitro against Rhizoctonia solani (RS) activity, with the EC₅₀ value of 26.0 µg/mL, which was equal to that of azoxystrobin. As well, in vivo experiments on rice leaves showed that compound 5u could effectively control RS, and the effect of 5u on the cell morphology of RS was observed by scanning electron microscopy.     

Spectroscopic,anti-bacterial,anti-cancer and molecular docking of Pd(II) and Pt(II) complexes with (E)-4-((dimethylamino)methyl)-2-((4,5-dimethylthiazol-2-yl)diazenyl)phenol ligand

New ligand (E)-4-((dimethylamino)methyl)-2-((4,5-dimethylthiazol-2-yl)diazenyl)phenol (HDmazo) was prepared by the coupling reaction between 4,5-dimethylthiazol-2-amine and 4-((dimethylamino)methyl)phenol. Moreover, the [MCl₂(HDmazo)] and [M(HDmazo)₂] [M^II = Pd and Pt] were prepared using the direct reaction of equivalent molar of HDmazo and Na₂PdCl₄ or K₂PtCl₄. The HDmazo and its complexes were investigated by different spectroscopic techniques. In complexes (1–2) HDmazo ligand behaves as bidentate style through the nitrogen of azo group and nitrogen of thiazole ring towards Pd(II) and Pt(II). Or in a bidentate fashion via the oxygen atom of the hydroxylate group and nitrogen atom of azo group as mono-anion in complexes (3–4). Further, the study of biological activity against four pathogenic bacteria showed that compound (3) exhibited good activity compared to other compounds. Additional the anti-tumor action against A2870 cell lines was screened, and the complexes (1) and (2) displayed good activity with 7.45 ± 0.98 µM and 13.23 ± 1.43 µM, respectively. The binding mechanism of the prepared compounds with EGFR tyrosine kinase, was investigated using molecular docking experiments.     

Pestalustaines A and B,unprecedented sesquiterpene and coumarin derivatives from endophytic fungus Pestalotiopsis adusta

Pestalustaines A (1) and B (2), one unique sesquiterpene possessing an unusual 5/6/7-fused tricyclic ring system and one unprecedented coumarin derivative bearing 6/6/5/5-fused tetracyclic ring system, were isolated from the plant-derived Pestalotiopsis adusta. Their structures with absolute configurations were established by extensive NMR analysis, X-ray crystallography, and CD spectra associated with TD-DFT calculation. Hypothetical biosynthetic pathways for compounds 1 and 2 are proposed. Compounds 1 and 2 showed weak to moderate cytotoxic activities against three human tumor cell lines HeLa, HCT116, and A549, whose IC₅₀ values were ranged from 21.01 to 55.43?μM.     

Vulgarisins B–D,three novel diterpenoids with a rare skeleton isolated from Prunella vulgaris Linn

Three new diterpenoids, vulgarisins B–D (1–3), have been isolated from a medicinal plant Prunella vulgaris Linn. These diterpenoids contain a rare 5/6/4/5 fused tetracyclic ring skeleton. Their structures were determined through the analysis of spectroscopic data, and the absolute configuration were further confirmed by single crystal X-ray diffraction as well as CD analysis. All the compounds were evaluated for their cytotoxicity activity, vulgarisins B (1) and C (2) demonstrated modest cytotoxicity activity against human lung carcinoma A549 cell line.     

Zamamidine C, 3,4-dihydro-6-hydroxy-10,11-epoxymanzamine A, and 3,4-dihydromanzamine J N-oxide, new manzamine alkaloids from sponge Amphimedon sp.

New manzamine alkaloids, zamamidine C (1), 3,4-dihydro-6-hydroxy-10,11-epoxymanzamine A (2), and 3,4-dihydromanzamine J N-oxide (3), have been isolated from an Okinawan marine sponge Amphimedon species. The structures and stereochemistries of 1-3 were elucidated from the spectroscopic data and chemical derivatization. Zamamidine C (1) is a new manzamine alkaloid possessing a second β-carboline ring via an ethylene unit at N-2 of manzamine D, while 3,4-dihydro-6-hydroxy-10,11-epoxymanzamine A (2) is the first manzamine alkaloid possessing an epoxide ring at C-10 and C-11. Zamamidine C (1) showed significant antitrypanosomal activity against Trypanosoma brucei brucei, the parasite associated with sleeping sickness, and antimalarial activity against Plasmodium falciparum, the causative agent of malaria in vitro.     

New antimitotic bicyclic peptides, celogentins D-H, and J, from the seeds of Celosia argentea

Six new bicyclic peptides, celogentins D-H (1-5) and J (6) have been isolated from the seeds of Celosia argentea, and the structures including its absolute stereochemistry were determined by using extensive NMR methods and chemical means. Celogentins E-H (2-5) and J (6) showed potent inhibition of tubulin polymerization, while the inhibitory activity of celogentin D (1) was modest. Structure-activity relationship study indicates that ring size of the bicyclic ring system including unusual β^s-Leu, Trp, and His residues would be important for their biological activity.     

Solanopubamine,a rare steroidal alkaloid from Solanum schimperianum: Synthesis of some new alkyl and acyl derivatives,their anticancer and antimicrobial evaluation

Solanopubamine (3β-amino-5α, 22αH, 25βH-solanidan-23β-ol), a steroidal alkaloid was isolated from the alkaloidal fraction of Solanum schimperianum in significant yield. Its structure was established by IR, positive ESI-MS, 1D and 2D NMR. The presence of -3β-NH₂ and -23β-OH groups was achieved through methylation, acetylation or coupling with octadecanoic and undec-11-enoic acids to produce six derivatives (2–7). Their structures were confirmed by spectroscopic analyses. Solanopubamine and semi-synthetic analogs are investigated for their in vitro cytotoxicity against a panel of human cancer cell lines and anti-microbial activity. Solanopubamine showed good antifungal activity only against Candida albicans and C. tenuis with MIC of 12.5 μg/mL. Semi-synthesized compounds (2–7) have failed to show anti-tumor and anti-microbial activities.     

CAN catalyzed one-pot synthesis and docking study of some novel substituted imidazole coupled 1,2,4-triazole-5-carboxylic acids as antifungal agents

The present work describes a facile,one-pot three component synthesis of a series of 3-[(4,5-diphenyl-2-substituted aryl/heteryl)-1H-imidazol-1-yl]-1H-1,2,4-triazole-5-carboxylic acid derivatives M(1-15).Benzil,aromatic aldehydes and 3-amino-l,2,4-triazole-5-carboxylic acid was refluxed in ethanol using cerric ammonium nitrate(CAN) as a catalyst to give the title compounds in good yields.The compounds were evaluated for their in vitro antifungal and antibacterial activity.Compounds M1,M9,and M15 were found to be equipotent against Candida albicans when compared with fluconazole.Compounds M2.M5,and M14 showed higher activity against Streptococcus pneumoniae.Escherichia coli and Streptococcus pyogenes,respectively,compared with ampicillin.Docking study of the newly synthesized compounds was performed,and the results showed good binding mode in the active sites of C albicans enzyme cytochrome P450 lanosterol 14α-demethylase.The results of in vitro antifungal activity and docking study showed that synthesized compounds had potential antifungal activity and can be further optimized and developed as a lead compound.     

Design,synthesis and biological evaluation of novel isoniazid hybrids

We herein report the design and synthesis of novel isoniazid derivatives. Isoniazid derived Schiff bases (3 a-d) were subjected to cyclization with acetic anhydride and sulphuric acid to yield the 5′-substituted-3′-acetyl-5-(pyridin-4-yl)-3H-spiro[indole-3, 2-[1′, 3′, 4’]oxadiazol]-2′-yl acetates (4 a-d) and 8′-substituted-3’-(pyridin-4-yl)[1′,3′,4’]oxadiazino [6,5-b]indoles (5 a-d) respectively. The advantages of spectral methods were used for the confirmation of the structure of all the newly synthesized hybrid molecules. Further, these compounds were evaluated for their antibacterial activity against B. Subtilis, S. aureus, E. coli & S. typhi, antifungal activity against C. albicans, C. oxysporum, A. Flavus & A. niger, and antimycobacterial activity against M. tuberculosis. Amongst, the compounds 4b, 4c and 5c showed excellent inhibitory activity against tested microorganisms. Also, the DNA cleavage activity of selected compounds was carried out by the AGE method.     

Design,synthesis and biological evaluation of isoxazole-naphthalene derivatives as anti-tubulin agents

In this study, a novel series of isoxazole-naphthalene derivatives as tubulin polymerization inhibitors were designed, synthesized and evaluated for their anti-proliferative activities against human breast cancer cell line MCF-7. Most of the synthesized compounds exhibited moderate to potent antiproliferative activity (IC₅₀ < 10.0 μM), as compared to cisplatin (15.24 ± 1.27 μM). Among them, compound 5j containing 4-ethoxy substitution at phenyl ring was found to be the most active compound with IC₅₀ value of 1.23 ± 0.16 μM. Mechanistic studies revealed that compound 5j arrested cell cycle at G2/M phase and induces apoptosis. Furthermore, in vitro tubulin polymerization assay showed that compound 5j displayed better inhibition activity on tubulin polymerization (IC₅₀ = 3.4 μM) than colchicine (IC₅₀ = 7.5 μM). Molecular docking study also revealed that compound 5j binds to the colchicine binding site of tubulin.     

Design,synthesis and antitumor activity of 3-substituted quinolone derivatives （Ⅰ）

A series of quinolone derivatives containing benzimidazole, benzoxazole or benzothiazole ring were synthesized. The cytotoxicity of 12 new compounds was evaluated in KB, Be17402, A2780 and HT-29 cell lines. Most of synthesized compounds showed moderate inhibitory activity against cancer cells. The inhibitory activities of 6k, against KB and A2780 tumor ceils are comparable to that of topotecan, one of topoisomerase I inhibitors.     

Synthesis,antiviral activity,and 3D-QSAR study of novel chalcone derivatives containing malonate and pyridine moieties

Several novel chalcone derivatives containing malonate and pyridine moieties were synthesized, and their structures were confirmed by ¹H nuclear magnetic resonance, ¹³C nuclear magnetic resonance, ¹⁹F nuclear magnetic resonance, infrared, and elemental analyses. Antiviral bioassays revealed that most of the compounds exhibited good antiviral activity against cucumber mosaic virus (CMV) at 500 μg/mL. In particular, compounds 5l and 5n showed significant curative activities against CMV in vivo with 50% effective concentration (EC₅₀) values of 186.2 and 211.5 μg/mL, respectively; these values are even better than that of ningnanmycin (330.5 μg/mL). A 3D quantitative structure–activity relationship study was carried out using the comparative molecular field analysis technique based on curative activities against CMV. Results revealed good predictive ability with cross-validated q² and non-cross-validated r² values of 0.517 and 0.990, respectively.     

DFT,solution, and crystal conformation of eremophilanolides

The minimum energy conformation of five eremophilanolides (1–5) from the tubercles of Psacalium paucicapitatum was calculated using density functional theory (DFT) at the B3LYP/6-31G¹ level. Comparison of the experimental ¹H–¹H coupling constant values of 1–5 with those generated employing a generalized Karplus-type relationship using dihedral angles extracted from the DFT calculation and from the crystal structures for 1 and 3–5 shows good agreement. The A ring of 1–5 adopts an almost perfect chair conformation with the Me-14 group in an axial position and the Me-15 in an equatorial position.