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This paper reports the synthesis and in vitro cytotoxicity evaluation of isatin-pyrrole derivatives 5–8, obtained from the appropriate isatins with pyrrole, with good yields and purity. The product structures were confirmed through spectroscopy methods. Furthermore, the MTT assay on the human liver cancer HepG2 cell lines revealed moderate activity in all compounds, which was highest in sample 6 (IC50 0.47 µM). The anticancer activity was affiliated with the presence of a nitro group at C-5 and N-methyl of the isatin scaffold.

N’-(5-nitro-2-oxoindolin-3-ylidene) thiophene-2-carbohydrazide (NH) was successfully synthesized as a ligand, then grafted onto the surface of mesoporous silica SBA-15via an aminopropyl bridge. The successful grafting of ligand NH onto the hybrid nanomaterial (SBA-15/APTES-NH) was confirmed by infrared spectroscopy. On excitation at 276 and 370 nm, the ligand NH and the hybrid nanomaterial SBA-15/APTES-NH showed a strong and narrow emission peak centered at 533 nm. By dispersing SBA-15/APTES-NH in an aqueous solution containing metal ions, the resulting solid materials showed a higher binding of NH sensing site to Fe3+ ions as compared to the others with a quench of the emission intensity up to 84%. This result showed that the hybrid nanomaterial is a potential chemosensor that requires development for the detection of metal ions.

The synthesis of indolin-2-one derivatives and in vitro anticancer activity on colon cancer were reported in the present study. The compounds contain a fluorine or a bromine in position 5, and a bromine in position 7. The results established that indolin-2-one with bromine in position 5 gave up to a 4-fold improved cytotoxicity over indolin-2-one with fluorine in position 5. The indolein-2-one with bromine in posititon 5 also exerted higher cytotoxicity compared to bromine in position 7. This work highlights the importance of halogen and their position in cytotoxicity.

This study examined the synthesis of isoniazid-isatin hydrazone derivatives 5-7, followed by an investigation on the in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv, and molecular docking. A yield of 81 - 92 % of these compounds was achieved, with structural characterization by spectroscopic methods (FTIR, NMR, HRMS). The in vitro antitubercular activity was evaluated against M. tuberculosis H37Rv, and the highest effect was observed in compound 7, with a minimum inhibitory concentration (MIC) of 0.017 mM, lower than rifampicin (MIC 0.048 mM), which served as the positive control. In addition, the molecular docking of 5-7 was performed to visualize the interaction of isoniazid-isatin hydrazone derivatives with the active site of InhA receptor, which was in agreement with the experimental data. The hydrogen bonding with Ser94 and pi-pi interaction with Phe41 and/or Phe97 on the InhA active site was pivotal for the antitubercular activity. HIGHLIGHTS Tuberculosis caused by Mycobacterium tuberculosis is one of the top ten leading causes of death globally The first and second lines of antituberculosis drugs are the prevalent treatment for this disease, but they show several drawbacks and are exacerbated by the occurrence of drug resistance The isoniazid-isatin hydrazone derivatives were designed through molecular hybridization and synthesized effectively and exhibited moderate to high activity against tuberculosis H37Rv Molecular docking study demonstrated that the hydrogen bonding with Ser94 and the pi-pi interaction with Phe41 and/or Phe97 are important for antitubercular activity GRAPHICAL ABSTRACT

Special attention has been given to red dragon fruit (Hylocereus polyrhizus) because of its unique natural compounds exhibiting wide biological activities. However, the potential use of the red dragon fruit peel has been less addressed. In the present work, simple extraction of red dragon fruit peel was carried out to study the fluorescence properties of the corresponding extracts in various solvents. The red dragon fruit peel was first separated, dried, and macerated for 24 hours using distilled water, ethanol, and acetone, separately. The results demonstrated that the peel extracts exhibited different photoluminescence properties depending on the solvent type. It was revealed that the ethanolic extract gave the highest fluorescence intensity among the other extracts. The ethanolic extract showed two excitation peaks at 290 and 359 nm, yielding different emission properties. Excitation at 290 nm gave one emission peak at 339 nm, while the excitation at 359 nm gave an emission peak at 436 nm. Such strong photoluminescence properties observed in the wide range of UV and visible regions demonstrated the potential use of the red dragon fruit peel as a photonic material. Spectroscopy study also proposed that the ethanolic extract would have polyphenol and chlorogenic acid as the main compounds.

One of the most lethal and frequent infectious diseases worldwide is tuberculosis. Multi and extensively tuberculosis drug-resistant constitutes a serious problem and emphasizes the need for novel anti-tubercular agents. Accordingly, various pyrazine-2-carboxamides were synthesized and evaluated as potential anti-tuberculosis agents. The synthesis involved reaction of pyrazinoic acids with thionyl chloride to yield acyl chlorides which on treatment with various anilines gave various pyrazine-2-carboxamides. Based on structure-activity relationships extracted from previously published, this paper reported the synthesis and molecular docking study of 6-chloropyrazine-2-carboxamides. Synthesis involved reaction of 6-chloropyrazinoic acid with 2,4,6-trichlorobenzoyl chloride instead of thionyl chloride which listed under the Chemical Weapons Convention as it may use for the production of chemical weapons. Structure identification of 6-chloropyrazine-2-carboxamides was carried out by 1H NMR, 13C NMR, FTIR, and high-resolution mass spectroscopy. It is predicted that 6-chloro-N-octylpyrazine-2-carboxamide has better bioactivity against Mycobacterium tuberculosis, based on molecular docking study.

1H-Indole-2,3-dione has attracted many attentions in the field of organic synthesis due to its easy modification with other organic compounds. On the other hand, 1H-indole-2,3-dione compound could also be used as chemosensor agent because it contains amide and carbonyl functional groups, which are able for binding as well as chelating metal ions. In the present work, we reported that 1H-indole-2,3-dione compound exhibits high sensing capability as well as high selective detection of Fe3+ ions through enhancement of its absorption peak at ultraviolet region. Particularly, a series of 0.5 mM of metal ions (Na+, K+, Ba2+, Ca2+, Co2+, Cu2+, Hg2+, Mg2+, Mn2+, Ni2+, Pb2+, Zn2+, Au3+, Al3+, Fe3+ and La3+) in distilled water was simply mixed with 0.05 mM of 1H-indole-2,3-dione in distilled water. Afterward, their UV-Vis spectral changes were recorded by using UV-Vis spectrophotometer. It was found that 1H-indole-2,3-dione itself gave two main absorption peaks at 242 and 302 nm. When the Fe3+ ions were added, the intensity of both absorption peaks was remarkably increased. From the UV-Vis titration experiment, limit of detection value was found to be 17.8 µM while limit of quantitation was found as 59.3 µM. This finding shows that the 1H-indole-2,3-dione gives a promising platform for fluorescent chemosensor agent for sensing of Fe3+ ion.

In the present work, a comprehensive statistical analysis was performed to evaluate the potential application of peel of local fruits from Malang, i.e. mangosteen, honey pineapple and red dragon fruits for natural yellow coloring agents. The yellow pigments from those fruit peels were extracted through a simple maceration method using distilled water, acetone and ethanol as the solvents. The CIE color space of the extracts was measured to obtain L*, a* and b* values. The obtained data were further analyzed using Principal Component Analysis (PCA), Multivariate Analysis of Variance (MANOVA) and Duncan Test to determine the most potent natural yellow coloring agent. All the extracts were appeared as mild to strong yellow liquid except for acetone extract for the peel of red dragon fruit extracts. From the CIE color space and PCA analysis, either ethanolic or acetone extracts of mangosteen appears as a strong yellow liquid and they are statistically not different. Interestingly, the MANOVA and Duncan test results are able to distinguish that the ethanolic extract of mangosteens’ peel as the best candidate for natural yellow coloring agents because of its lowest L* and also highest b* variable values.

One of the most frequent and widespread infectious diseases especially in developing countries is tuberculosis (TB). The number of TB drug resistant tend to increase, and there has been no new TB drug introduce since the 1960s. Six 2-Thiophenecarboxylic acid hydrazide derivatives were synthesized in 90-97% yields, and 2-thiophenecarbonylhydrazone-5, 7-dibromoisatin showed the highest activity in inhibiting M. tuberculosis H37Rv.