Phthaloyl amino acids as anti-inflammatory and immunomodulatory prototypes

Thiazole, Isatin and Phthalimide Derivatives Tested in vivo against Cancer Models: A Literature Review of the Last Six Years

BACKGROUND

Cancer is a disease characterized by the abnormal multiplication of cells and is the second leading cause of death in the world. The search for new effective and safe anticancer compounds is ongoing due to factors such as low selectivity, high toxicity, and multidrug resistance. Thus, heterocyclic compounds derived from isatin, thiazole and phthalimide that have achieved promising in vitro anticancer activity have been tested in vivo and in clinical trials.

OBJECTIVE

This review focused on the compilation of promising data from thiazole, isatin, and phthalimide derivatives, reported in the literature between 2015 and 2022, with in vivo anticancer activity and clinical trials.

METHODS

A bibliographic search was carried out in the PUBMED, MEDLINE, ELSEVIER, and CAPES PERIODIC databases, selecting relevant works for each pharmacophoric group with in vivo antitumor activity in the last 6 years.

RESULTS

In our study, 68 articles that fit the scope were selected and critically analyzed. These articles were organized considering the type of antitumor activity and their year of publication. Some compounds reported here demonstrated potent antitumor activity against several tumor types.

CONCLUSION

This review allowed us to highlight works that reported promising structures for the treatment of various cancer types and also demonstrated that the privileged structures thiazole, isatin and phthalimide are important in the design of new syntheses and molecular optimization of compounds with antitumor activity.

Phthalic anhydride (PA): a valuable substrate in organic transformations

This review has been centralized on applications of phthalic anhydride (PA) as a valuable and significant heterocyclic substrate in two- and multicomponent organic reactions. The article has been subdivided into the following parts: (i) PA introduction by focusing on its characterization, synthesizing procedure, and multiple-aspect applications. In addition, the previous review articles based on PA have also been indicated; (ii) the applications of PA as a substrate have been subdivided into parts with a glance on the reaction components numbers; (iii) the applications of PA in esterification reactions; and (iv) some examples of PA in multistep synthesis. The review covers the corresponding literature up to the end of 2022. According to the abovementioned classifications, PA is a potent substrate to design a wide range of heterocyclic compounds that possess various kinds of properties and applications in chemistry, industry, and pharmaceuticals.

Synthesis and biological evaluation of novel sinomenine derivatives as anti-inflammatory and analgesic agent

Sinomenine (SIN) has long been known as an anti-inflammatory drug, while poor efficiency and large-dose treatment had limited its further application. A series of novel SIN derivatives 1–26 were designed and synthesized to improve its anti-inflammatory activity. The anti-inflammatory activity evaluation showed most of the derivatives exhibited enhanced anti-inflammatory activity in vitro compared to SIN. Compound 17 significantly inhibited LPS-induced secretion of pro-inflammatory factors NO (IC₅₀ = 30.28 ± 1.70 μM), and suppressed the expression of iNOS, IL-6 and TNF-α in RAW264.7 cells. Moreover, compound 17 showed excellent anti-inflammatory in mouse paw edema. Immunohistochemistry results revealed that compound 17 exerted anti-inflammatory activity by inhibiting the pro-inflammatory cytokine TNF-α. Furthermore, compound 17 exhibited an analgesic effect in vivo. The results attained in this study indicated that compound 17 had the potential to be developed into an anti-inflammation and analgesic agent.

A series of novel sinomenine derivatives were designed and synthesized. Among them, compound 17 showed strong anti-inflammatory and analgesic activities.

Visible-Light-Driven Redox Neutral Direct C-H Amination of Glycine Derivatives and Peptides with N-Acyloxyphthalimides

A room temperature, visible-light-promoted and redox neutral direct C-H amination of glycine and peptides has been firstly accomplished by using N-acyloxyphthalimide or -succinimide as nitrogen-radical precursor. The present strategy provides ways to introduce functionalities such as N-acyloxyphthalimide or -succinimide specifically to terminal glycine segment of peptides. Herein, mild conditions and high functional-group tolerance allow the preparation of non-natural α-amino acids and modification of corresponding peptides in this way.

Synthesis, in vitro and in vivo biological evaluation of novel lappaconitine derivatives as potential anti-inflammatory agents

Lappaconitine (LA), a natural compound with a novel C18-diterpenoid alkaloid skeleton, displayed extensive biological profile. Recent research on LA is focused mainly on its anti-tumor and analgesic effects, and therefore we aimed to investigate its anti-inflammatory potential. A series of novel LA derivatives with various substituents on the 20-N position was designed and synthesized. In the initial screening of LA derivatives against NO production, all the target compounds, except compound E2, exhibited excellent inhibitory ability relative to that of LA. Particularly, compound A4 exhibited the most potent inhibition with IC₅₀ of 12.91 μmol/L. The elementary structure-activity relationships (SARs) of NO inhibitory activity indicated that replacement of the benzene ring with an electron donating group could improve the anti-inflammatory efficacy. Furthermore, compound A4 shows an anti-inflammatory mechanism by inhibiting NO, PGE2, and TNF-α generation via the suppression of NF-κB and MAPK signaling pathways. Notably, compound A4 could exert a significant therapeutic effect on LPS-induced acute lung injury (ALI) in vivo. Based on the above research, we further investigated the preliminary pharmacokinetic property of A4 in rats. Therefore, compound A4 could be a promising candidate for the development of anti-inflammatory agents in the future.

Molecular Hybrids of N-Phthaloylglycyl Hydrazide and Hydrazinecarbothioamide with Anti-inflammatory and Anti-oxidant Activities

BACKGROUND

Oxidative stress due to high levels of reactive organic species is the cause of the progression of inflammation in various diseases. The molecules possessing both anti-inflammatory and antioxidant activity can be the promising key to treat inflammatory diseases. Phthalimide and hydrazinecarbothioamide are anti-inflammatory and anti-oxidant pharmacophores.

OBJECTIVE

Molecular hybrids possessing above two pharmacophores were designed. A series of N-phenyl substituted 2-(2-(1,3-dioxoisoindolin-2-yl)acetyl)-N-phenylhydrazine-1-carbothioamide (CGS compounds) was synthesized and evaluated for biological activities.

METHODS

N-phthaloylglycyl hydrazide was reacted with unsubstituted/substituted phenyl isothiocyanates to yield CGS compounds. Synthesized compounds were evaluated for in vivo anti-inflammatory activity in carrageenan rat paw edema model, and in vitro anti-oxidant activity by DPPH assay. Levels of TNF-α and oxidative stress at the site of inflammation were measured. The genetic algorithm-PLS regression based QSAR model correlating the effect of N-phenyl substituent on the anti-inflammatory activity was developed. Further, the interaction of the active compound in the TNF-α binding pocket was studied by in silico docking.

RESULTS

Compound containing the 2-OCH3, 4-NO2 (CGS-5); 4-CF3 (CGS-9); 4-NO2 (CGS-3) showed significant anti-inflammatory activity (percentage inhibition of paw edema after 3 hour = 58.24, 50.38, 40.05, respectively) and potent anti-oxidant activity (IC50 =0.045, 0.998, 0.285 μg/ml, respectively). Reduced levels of TNF- α and increased levels of GSH were observed for the above three compounds. Descriptors for QSAR model identified by GA-PLS were WPSA1, Weta1unity, WDunity, SC3, VC5, MlogP, and WTPT3. The identified model was highly predictive, and value of root mean square error of prediction for internal (leave one out) and external validation was: 1.579, 1.325.

CONCLUSION

Molecular hybrids of phthalimide and hydrazinecarbothioamide were synthesized. Some of the compounds possessed promising anti-inflammatory and anti-oxidant activities.

Privileged Structures in the Design of Potential Drug Candidates for Neglected Diseases

Background:

Privileged motifs are recurring in a wide range of biologically active compounds that reach different pharmaceutical targets and pathways and could represent a suitable start point to access potential candidates in the neglected diseases field. The current therapies to treat these diseases are based in drugs that lack of the desired effectiveness, affordable methods of synthesis and allow a way to emergence of resistant strains. Due the lack of financial return, only few pharmaceutical companies have been investing in research for new therapeutics for neglected diseases (ND).

Methods:

Based on the literature search from 2002 to 2016, we discuss how six privileged motifs, focusing phthalimide, isatin, indole, thiosemicarbazone, thiazole, and thiazolidinone are particularly recurrent in compounds active against some of neglected diseases.

Results:

It was observed that attention was paid particularly for Chagas disease, malaria, tuberculosis, schistosomiasis, leishmaniasis, dengue, African sleeping sickness (Human African Trypanosomiasis - HAT) and toxoplasmosis. It was possible to verify that, among the ND, antitrypanosomal and antiplasmodial activities were between the most searched. Besides, thiosemicarbazone moiety seems to be the most versatile and frequently explored scaffold. As well, phthalimide, isatin, thiazole, and thiazolidone nucleus have been also explored in the ND field.

Conclusion:

Some described compounds, appear to be promising drug candidates, while others could represent a valuable inspiration in the research for new lead compounds.

Neuropharmacological Screening of Chiral and Non-chiral Phthalimide- Containing Compounds in Mice: in vivo and in silico Experiments

Background:

Thalidomide, the first synthesized phthalimide, has demonstrated sedative- hypnotic and antiepileptic effects on the central nervous system. N-substituted phthalimides have an interesting chemical structure that confers important biological properties.

Objective:

Non-chiral (ortho and para bis-isoindoline-1,3-dione, phthaloylglycine) and chiral phthalimides (N-substituted with aspartate or glutamate) were synthesized and the sedative, anxiolytic and anticonvulsant effects were tested.

Method:

Homology modeling and molecular docking were employed to predict recognition of the analogues by hNMDA and mGlu receptors. The neuropharmacological activity was tested with the open field test and elevated plus maze (EPM). The compounds were tested in mouse models of acute convulsions induced either by pentylenetetrazol (PTZ; 90 mg/kg) or 4-aminopyridine (4-AP; 10 mg/kg).

Results:

The ortho and para non-chiral compounds at 562.3 and 316 mg/kg, respectively, decreased locomotor activity. Contrarily, the chiral compounds produced excitatory effects. Increased locomotor activity was found with S-TGLU and R-TGLU at 100, 316 and 562.3 mg/kg, and S-TASP at 316 and 562.3 mg/kg. These molecules showed no activity in the EPM test or PTZ model. In the 4-AP model, however, S-TGLU (237.1, 316 and 421.7 mg/kg) as well as S-TASP and R-TASP (316 mg/kg) lowered the convulsive and death rate.

Conclusion:

The chiral compounds exhibited a non-competitive NMDAR antagonist profile and the non-chiral molecules possessed selective sedative properties. The NMDAR exhibited stereoselectivity for S-TGLU while it is not a preference for the aspartic derivatives. The results appear to be supported by the in silico studies, which evidenced a high affinity of phthalimides for the hNMDAR and mGluR type 1.

Experimental and Theoretical Thermochemistry of the Isomers 3- and 4-Nitrophthalimide

This work presents a thermochemical study of two derivatives of phthalimide: the isomers 3-nitrophthalimide and 4-nitrophthalimide. The enthalpies of formation for these compounds in the solid phase were obtained by combustion calorimetry. Using ths thermogravimetry technique, the enthalpies of vaporization were obtained. The enthalpies of sublimation were calculated from enthalpies of fusion and vaporization. From experimental data and by ab initio methods, the enthalpies of formation in the gas phase were calculated. With these results, it was possible to determine their relative stability, and it was found that 4-nitrophthalimide is more stable than its isomer 3-nitrophthalimide. This tendency is similar to that of 3-nitrophthalic anhydride and 4-nitrophthalic anhydride, as reported in a previous work by our research group. The enthalpy of isomerization was also obtained, and a good correlation with that of phthalic anhydride derivatives was found. Finally, with the values obtained, the enthalpic difference resulting when the imide group is substituted by an anhydride group was determined.

Are salty liquid food flavorings in vitro antitumor substances?

The objective of this study was to evaluate the antiproliferative, cytotoxic and genotoxic potential of salty liquid synthetic flavorings of Butter, Cheddar Cheese and Onion. The antiproliferative potential (2.9-1500 µg/mL) was assessed by MTT assay after 72h using the human tumor lines SF-295 (glioblastoma), OVCAR-8 (ovarian), HCT-116 (colon) and HL-60 (promyelocytic leukemia) and primary cultures of murine Sarcoma 180 (S180) and peripheral blood mononuclear cells (PBMC). Allium cepa bulbs were exposed to growing respective doses (1 mL and 2 mL). Only Butter and Cheddar flavorings revealed cytotoxic activity on cancer cells, with IC50 values ranging from 125.4 µg/mL (Cheddar - HCT-116) to 402.6 µg/mL (Butter - OVCAR-8). Butter flavoring was the most cytotoxic on PBMC (136.3 µg/mL) and increased cell division rate in relation to the mitotic index but did not cause cellular aberrations. Onion and Cheddar flavorings reduced the mitotic index after 24h and 48h exposure, but only Onion flavoring resulted in cellular aberrations and mitotic spindle abnormalities, such as anaphase and telophase bridges, micronucleated cells, conchicine-metaphases and amplifications. So, Butter, Onion and/or Cheddar flavorings caused significant changes in the division of meristematic cells of A. cepa and presented cytotoxic action even on decontrolled proliferating human tumor cells.

Antitumor and immunomodulatory activities of thiosemicarbazones and 1,3-Thiazoles in Jurkat and HT-29 cells

Cancer remains a high incidence and mortality disease, causing around 8.2 million of deaths in the last year. Current chemotherapy needs to be expanded, making research for new drugs a necessary task. Immune system modulation is an emerging concept in cancer cell proliferation control. In fact, there are a number of mechanisms underlying the role immune system plays in tumor cells. In this work, we describe the structural design, synthesis, antitumor and immunomodulatory potential of 31 new 1,3-thiazole and thiosemicarbazone compounds. Cisplatin was used as anticancer drug control. Cytotoxicity against J774A.1 macrophages and antitumor activity against HT-29 and Jurkat cells was determined. These 1,3-thiazole and thiosemicarbazone compounds not only exhibited cytotoxicity in cancer cells, but were able to cause irreversible cancer cell damage by inducing necrosis and apoptosis. In addition, these compounds, especially pyridyl-thiazoles compounds, regulated immune factors such as interleukin 10 and tumor necrosis factor, possible by directing immune system in favor of modulating cancer cell proliferation. By examining their pharmacological activity, we were able to identify new potent and selective anticancer compounds.

Cytotoxic and toxicological effects of phthalimide derivatives on tumor and normal murine cells

Eleven phthalimide derivatives were evaluated with regards to their antiproliferative activity on tumor and normal cells and possible toxic effects. Cytotoxic analyses were performed against murine tumors (Sarcoma 180 and B-16/F-10 cells) and peripheral blood mononuclear cells (PBMC) using MTT and Alamar Blue assays. Following, the investigation of cytotoxicity was executed by flow cytometry analysis and antitumoral and toxicological potential by in vivo techniques. The molecules 3b, 3c, 4 and 5 revealed in vitro cytotoxicity against Sarcoma 180, B-16/F-10 and PBMC. Since compound 4 was the most effective derivative, it was chosen to detail the mechanism of action after 24, 48 and 72 h exposure (22.5 and 45 µM). Sarcoma 180 cells treated with compound 4 showed membrane disruption, DNA fragmentation and mitochondrial depolarization in a time- and dose-dependent way. Compounds 3c, 4 and 5 (50 mg/kg/day) did not inhibit in vivotumor growth. Compound 4-treated animals exhibited an increase in total leukocytes, lymphocytes and spleen relative weight, a decreasing in neutrophils and hyperplasia of spleen white pulp. Treated animals presented reversible histological changes. Molecule 4 had in vitro antiproliferative action possibly triggered by apoptosis, reversible toxic effects on kidneys, spleen and livers and exhibited immunostimulant properties that can be explored to attack neoplasic cells.