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The study of isatin, as well as its kind of derivatives, has become a hot topic for a long time. To explore the new compounds and bioactivities, in this work, a series of simple isatin Mannich and Schiff bases was synthesized through the condensation reac

In this work, a series of N-substituted isatin derivatives was synthesized by different reactions. The synthesized isatin derivatives were characterized by NMR, MS and elemental analysis. Then the anti-Tumor activities of these compounds were evaluated through the cytotoxicity against A549 and P388 cell line test. The results show that several compounds show much higher anti-Tumor activity than that of isatin, and there is an even-odd effect in the structure activity relationship.

Tuberculosis (TB) remains among the world's great public health challenges. Worldwide resurgence of TB is due to two major problems: the AIDS epidemic, which started in the mid-1980s, and the outbreak of multidrug resistant (MDR) TB. Thus, there is an urgent need for anti-TB drugs with enhanced activity against MDR strains. In recent years, Schiff bases of 1H-indole-2,3-diones are reported to exhibit anti-TB activity. On the other hand, several quinolone antibacterial agents have been examined as inhibitors of TB, as well as other mycobacterial infections. Accordingly, the current work involved design and synthesis of Schiff bases of nalidixic acid carbohydrazide and isatin derivatives (5,6a-f and 7,8a-c). Structures of the synthesized derivatives were confirmed on the bases of spectral methods of analyses. Anti-TB activity of the synthesized derivatives was investigated against four Mycobacterium strains: Mycobacterium intercellulari, Mycobacterium xenopi, Mycobacterium cheleneo and Mycobacterium smegmatis. Modest anti-TB activity was observed within the investigated compounds, however, compound 5f revealed potent anti-TB activity with MIC 0.625 μg/ml, which is 20 times greater than the reference drug isoniazid, INH, (MIC = 12.5 μg/ml). A hypothetical pharmacophore model was built using Molecular Operating Environment (MOE) program and 10 compounds structurally related to the synthesized ones with reported anti-TB activity. The Pharmacophoric model built revealed the necessity of the following pharmacophoric features for anti-TB activity: aromatic center, hydrogen bond acceptor/metal ligator center, hydrogen bond donor center and aromatic center/hydrophobic area. Theses features were consistent with the found anti-TB activity of the tested compounds.

Ester prodrugs of aspirin la, ibuprofen 1b, naproxen 1c and indomethacin 1d were synthesized using N-Hydroxymethylsuccinimide (HMSI) 3 and N- hydroxymethylisatin (HMIS) 4 as promoieties to reduce their gastrointestinal toxicity and improve bioavailability. Additionally, the kinetics of hydrolysis of the synthesized prodrugs 5a-d and 6a-d were studied at 37°C in non-enzymatic simulated gastric fluid (SGF; hydrochloric acid buffer pH = 1.2); 0.02 M phosphate buffer (pH = 7.4); 80% human plasma and 10% rat liver homogenate. The results indicate higher chemical stability of the ester prodrugs in non-enzymatic SGF (t(1/2) ? 6.5-18.6 h) and rapid conversion to the parent drugs in 80% human plasma (t(1/2) ? 11.4-235 min) as well as in 10% rat liver homogenates (t(1/2) ? 12.0-90.0 min). As a general pattern, the HMSI esters 5a-d revealed higher chemical stability than the corresponding HMIS analogues 6a-d. The pH-rate profile of 5c and 6a indicated maximum stability of the former at pH = 1.2-8.0 and of the latter at pH = 1.2-4.0. The distribution coefficient (D7.4) values of the prodrugs 5a-d, 6a-d and the parent drugs 1a-d in an n-octanol/phosphate buffer (pH =7.4) system indicated enhanced lipophilic properties of the prodrugs. Furthermore, the HMIS ester prodrugs 6a-d are more lipophilic than the corresponding HMSI derivatives 5a-d. In vivo ulcerogenicity studies using scanning electron microscopy on stomach specimens of rats treated with an oral dose for 4 d revealed that the synthesized ester prodrugs are significantly less irritating to gastric mucosa than the parent drugs. These results suggested HMSI and/or HMIS esters possess good potential as prodrugs with an improved therapeutic index for oral delivery of NSAIDs.