Ratchanok Pingaew

Synthesis and molecular docking of 1,2,3-triazole-based sulfonamides as aromatase inhibitors.

A series of 1,4-disubstituted-1,2,3-triazoles (13-35) containing sulfonamide moiety were synthesized and evaluated for their aromatase inhibitory effects. Most triazoles with open-chain sulfonamide showed significant aromatase inhibitory activity (IC50=1.3-9.4μM). Interestingly, the meta analog of triazole-benzene-sulfonamide (34) bearing 6,7-dimethoxy substituents on the isoquinoline ring displayed the most potent aromatase inhibitory activity (IC50=0.2μM) without affecting normal cell. Molecular docking of these triazoles against aromatase revealed that the compounds could snugly occupy the active site of the enzyme through hydrophobic, π-π stacking, and hydrogen bonding interactions. The potent compound 34 was able to form hydrogen bonds with Met374 and Ser478 which were suggested to be the essential residues for the promising inhibition. The study provides compound 34 as a potential lead molecule of anti-aromatase agent for further development.

Antioxidant, cytotoxicity, and QSAR study of 1-adamantylthio derivatives of 3-picoline and phenylpyridines

A series of isomeric α- and β-(1-adamantylthio)pyridines were previously documented to possess interesting antimicrobial and antimalarial activities. In this study, the antioxidant and cytotoxic potentials of 1-adamantylthio-3-methyl and 2-,3-,4-phenylpyridines (1–10) were investigated. The tested compounds were shown to exhibit interesting superoxide (SOD)- and free radical (DPPH)-scavenging activities as well as cytotoxic activities. Particularly, β-(1-adamantylthio)-4-phenylpyridine (8) was shown to be the most potent antioxidant and cytotoxic compound. QSAR studies revealed that dipole moment (μ) and electrophilic index (ωi) were the most important descriptors accounting for the observed SOD activities. Compounds with high μ and ωi values were observed to display high SOD activity. Inversely, compounds with the lowest atomic polarizability (MATS4p) exhibited the highest DPPH activity. Other quantum chemical descriptors such as atomic masses (GATS4m), ωi, and LUMO energy were also well correlated with cytotoxicity. The findings demonstrated that thiopyridine 8 is a potential lead compound that should be further investigated in drug discovery efforts. The QSAR results offer good prospect for the rational design of novel compounds with robust bioactivities.

Synthesis, Cytotoxic and Antimalarial Activities of Benzoyl Thiosemicarbazone Analogs of Isoquinoline and Related Compounds

Thiosemicarbazone analogs of papaveraldine and related compounds 1–6 were synthesized and evaluated for cytotoxic and antimalarial activities. The cytotoxic activity was tested against HuCCA-1, HepG2, A549 and MOLT-3 human cancer cell lines. Thiosemicarbazones 1–5 displayed cytotoxicity toward all the tested cell lines, while compounds 2–5 selectively showed potent activity against the MOLT-3 cell lines. Significantly, N(4)-phenyl-2-benzoylpyridine thiosemicarbazone 4 exhibited the most potent activity against HuCCA-1, HepG2, A549 and MOLT-3 cell lines with IC50 values of 0.03, 4.75, 0.04 and 0.004 µg/mL, respectively. In addition, 2-benzoylpyridine thio-semicarbazones 3 and 4 showed antimalarial activity against Plasmodium falciparum with IC50 of 10-7 to < 10-6 M. The study demonstrates the quite promising activity of analog 4 as a lead molecule for further development.

Novel 1,4-naphthoquinone-based sulfonamides: Synthesis, QSAR, anticancer and antimalarial studies

A novel series of 1,4-naphthoquinones (33-44) tethered by open and closed chain sulfonamide moieties were designed, synthesized and evaluated for their cytotoxic and antimalarial activities. All quinone-sulfonamide derivatives displayed a broad spectrum of cytotoxic activities against all of the tested cancer cell lines including HuCCA-1, HepG2, A549 and MOLT-3. Most quinones (33-36 and 38-43) exerted higher anticancer activity against HepG2 cell than that of the etoposide. The open chain analogs 36 and 42 were shown to be the most potent compounds. Notably, the restricted sulfonamide analog 38 with 6,7-dimethoxy groups exhibited the most potent antimalarial activity (IC₅₀ = 2.8 μM). Quantitative structure-activity relationships (QSAR) study was performed to reveal important chemical features governing the biological activities. Five constructed QSAR models provided acceptable predictive performance (Rcv 0.5647-0.9317 and RMSEcv 0.1231-0.2825). Four additional sets of structurally modified compounds were generated in silico (34a-34d, 36a-36k, 40a-40d and 42a-42k) in which their activities were predicted using the constructed QSAR models. A comprehensive discussion of the structure-activity relationships was made and a set of promising compounds (i.e., 33, 36, 38, 42, 36d, 36f, 42e, 42g and 42f) was suggested for further development as anticancer and antimalarial agents.

Synthesis, anticancer activity and QSAR study of 1,4-naphthoquinone derivatives

A series of 2-substituted amino-3-chloro-1,4-naphthoquinone derivatives (3-12) were synthesized as anticancer agents and tested against four cancer cell lines including HepG2, HuCCA-1, A549 and MOLT-3. The most potent cytotoxic activity against the HepG2, HuCCA-1 and A549 cell lines was found to be m-acetylphenylamino-1,4-naphthoquinone (8) affording IC50 values of 4.758, 2.364 and 12.279 μM, respectively. On the other hand, p-acetylphenylamino-1,4-naphthoquinone (9) exhibited the most potent cytotoxic activity against the MOLT-3 cell line with an IC50 of 2.118 μM. Quantitative structure-activity relationship (QSAR) investigations provided good predictive performance as observed from cross-validated R of 0.9177-0.9753 and RMSE of 0.0614-0.1881. The effects of substituents at the 2-amino position on the naphthoquinone core structure and its corresponding influence on the cytotoxic activity were investigated by virtually constructing additional 1,4-naphthoquinone compounds (13-36) for which cytotoxic activities were predicted using equations obtained from the previously constructed QSAR models. Interpretation of informative descriptors from QSAR models revealed pertinent knowledge on physicochemical properties governing the cytotoxic activities of tested cancer cell lines. It is anticipated that the QSAR models developed herein could provide guidelines for further development of novel and potent anticancer agents.

Synthesis of N-Substituted 5-Iodouracils as Antimicrobial and Anticancer Agents

This study reports the synthesis of some substituted 5-iodouracils and their bioactivities. Alkylation of 5-iodouracils gave predominately N1-substituted-(R)-5-iodouracil compounds 7a-d (R = n-C4H9, s-C4H9, CH2C6H11, CH2C6H5) together with N1,N3-disubstituted (R) analogs 8a-b (R = n-C4H9, CH2C6H11). Their antimicrobial activity was tested against 27 strains of microorganisms using the agar dilution method. The analogs 7a, 7c and 7d displayed 25-50% inhibition against Branhamella catarrhalis, Neisseria mucosa and Streptococcus pyogenes at 0.128 mg/mL. No antimalarial activity was detected for any of the analogs when tested against Plasmodium falciparum (T9.94). Their anticancer activity was also examined. Cyclohexylmethyl analogs 7c and 8b inhibited the growth of HepG2 cells. Significantly, N1,N3-dicyclohexylmethyl analog 8b displayed the most potent anticancer activity, with an IC50 of 16.5 μg/mL. These 5-iodouracil analogs represent a new group of anticancer and antibacterial agents with potential for development for medicinal applications.

Discovery of novel 1,2,3-triazole derivatives as anticancer agents using QSAR and in silico structural modification

AbstractConsiderable attention has been given on the search for novel anticancer drugs with respect to the disease sequelae on human health and well-being. Triazole is considered to be an attractive scaffold possessing diverse biological activities. Structural modification on the privileged structures is noted as an effective strategy towards successful design and development of novel drugs. The quantitative structure–activity relationships (QSAR) is well-known as a powerful computational tool to facilitate the discovery of potential compounds. In this study, a series of thirty-two 1,2,3-triazole derivatives (1–32) together with their experimentally measured cytotoxic activities against four cancer cell lines i.e., HuCCA-1, HepG2, A549 and MOLT-3 were used for QSAR analysis. Four QSAR models were successfully constructed with acceptable predictive performance affording RCV ranging from 0.5958 to 0.8957 and RMSECV ranging from 0.2070 to 0.4526. An additional set of 64 structurally modified triazole compounds (1A–1R, 2A–2R, 7A–7R and 8A–8R) were constructed in silico and their predicted cytotoxic activities were obtained using the constructed QSAR models. The study suggested crucial moieties and certain properties essential for potent anticancer activity and highlighted a series of promising compounds (21, 28, 32, 1P, 8G, 8N and 8Q) for further development as novel triazole-based anticancer agents.

Investigation on biological activities of anthranilic acid sulfonamide analogs

In the previous studies, the cytotoxicities of anthranilate sulfonamides were investigated. Herein, the bioactivities of 4-substituted (X = NO2, OCH3, CH3, Cl) benzenesulfonamides of anthranilic acid (5-8) are reported. The results revealed that all sulfonamides selectively exerted antifungal activity (25-50 % inhibition) against C. albicans at 4 μg/mL. Furthermore, compounds 6 and 8 show antioxidative (SOD) activity. These sulfonamides, except for 6, selectively display cytotoxic effects toward MOLT-3 cells. It is interesting to note that sulfonamides with electron withdrawing substituent (5, X = NO2) exhibited the highest cytotoxicity. This study provided preliminary structure-activity relationship of the anthranilic sulfonamides that is useful for further in-depth investigation.

Beta-(1-adamantylthio)pyridine analogs as antimicrobials and antimalarials

An array of interesting activities for bioactive 3-substituted thiopyridines have previously been reported. Herein, a series of αand β-(1-adamantylthio) analogs of 3-picoline and phenylpyridines were prepared and investigated for antimicrobial (agar dilution method against 21 strains of microorganisms) and antimalarial (against P. falciparum) activities. It was found that β-thiopyridines, 5-(1-adamantylthio)-3-picoline (7) and 3-(1-adamantylthio)-4phenylpyridine (8) are novel antimicrobials and antimalarials. Significantly, analogs 7 and 8 are very potent antimicrobials with MIC range of 2-32 μg/mL where 8 being the most potent. The β-sulfides 7 and 8 selectively inhibited the growth of tested gram-positive bacteria, but inactive against gram-negative bacilli including the members of Enterobacteriaceae. This study identified new antimicrobials that represent promising lead compounds suitable for further preclinical and clinical development.

Roles of Pyridine and Pyrimidine Derivatives as Privileged Scaffolds in Anticancer Agents.

BACKGROUND Cancer has been considered to be a global health concern due to the impact of disease on the quality of life. The continual increase of cancer cases as well as the resistance of cancer cells to the existing drugs have driven the search for novel anticancer drugs with better potency and selectivity, improved pharmacokinetic profiles, and minimum toxicities. Pyridine and pyrimidine are presented in natural products and genetic materials. These pyridine/pyrimidine core structures have been noted for their roles in many biological processes as well as in cancer pathogenesis, which make such compounds become attractive scaffolds for discovery of novel drugs. RESULTS & CONCLUSION In the recent years, pyridine- and pyrimidine-based anticancer drugs have been developed based on structural modification of these core structures (i.e., substitution with moieties and rings, conjugation with other compounds, and coordination with metal ions). Detailed discussion is provided in this review to highlight the potential of these small molecules as privileged scaffolds with attractive properties and biological activities for the search of novel anticancer agents.