Anticancer perspectives of monocarbonyl analogs of curcumin: A decade (2014-2024) review

Monocarbonyl analogs of curcumin (MACs) represent structurally modified versions of curcumin. The existing literature indicates that MACs exhibit enhanced anticancer properties compared with curcumin. Numerous research articles in recent years have emphasized the significance of MACs as effective anticancer agents. This review focuses on the latest advances in the anticancer potential of MACs, from 2014 to 2024, including discussions on their mechanism of action, structure-activity relationship (SAR), and in silico molecular docking studies.

Fluorinated and N-Acryloyl-Modified 3,5-Di[(E)-benzylidene]piperidin-4-one Curcuminoids for the Treatment of Pancreatic Carcinoma

Pancreatic carcinoma is a cancer disease with high mortality. Thus, new and efficient treatments for this disease are badly needed. Curcumin has previously shown promising effects in pancreatic cancer patients; however, this natural compound suffers from inadequate efficacy and bioavailability, preventing its clinical approval. The synthetic curcuminoid EF24 was developed with activities superior to curcumin against various cancer types. In this study, a series of analogs of EF24 were investigated for anticancer effects on pancreatic carcinoma models. A distinct activity boost was achieved by straightforward N-acrylation of EF24 analogs, in particular, of compounds bearing 3-fluoro-4-methoxybenzylidene, 3,4-difluorobenzylidene, and 4-trifluoromethylbenzylidene moieties, while no improvement was seen for N-acryloyl-modified EF24. Apoptosis induction and suppression of phospho-STAT3 levels were determined, the latter corroborated by docking of active curcuminoids into STAT3. Hence, promising new clues for the development of efficient and superior curcuminoids as valuable treatment options for one of the most lethal cancer diseases were discovered in this study.

Synthesis of Novel Bis-imino and Bis-amino Curcuminoids for Evaluation of Their Anticancer and Antibacterial Activity

A new set of curcumin analogues with a Schiff base moiety were synthesized from a bis-aldehyde derivative of hydroxybenzylidene cyclohexanone and various alicyclic and aromatic amines. The single crystals of compound 2 (bis-aldehyde), compound 3b (bis-cyclohexylimino derivative), and compound 3c (bis-1-imino piperidyl derivative) were developed. The said bis-imino and bis-amino curcuminoids were tested for anticancer activity against MCF-7 utilizing the conventional MTT assay. These Schiff bases had significantly higher anticancer efficacy than curcumin and methotrexate against MCF-7 cell lines. Compounds 3k, 3b, and 3l have the highest efficacy among all synthesized curcuminoids. The MTT results are in accordance with the binding affinities found by docking the said molecules with HER2 Tyrosine Kinase (HER2-TK). Compound 3b is identified as a promising HER2-TK inhibitor and also shows effective inhibition against Gram-positive bacteria Staphylococcus aureus.

Design, synthesis, crystal structure, and in vitro antibacterial activities of sulfonamide derivatives bearing the 4-aminoquinazoline moiety

A total of 66 sulfonamide derivatives bearing the 4-aminoquinazoline moiety were designed and synthesized, and their structures were fully characterized by ¹H NMR, ¹³C NMR, and HRMS techniques. Among them, the structures of compounds 5A10 and 5B11 were further confirmed through X-ray single-crystal diffraction analyses. The bioassay results indicated that some of the target compounds displayed higher inhibition activities in vitro against the tested phytopathogenic bacteria. For example, compound 5A26 exhibited a strong anti-Xanthomonas oryzae pv. oryzicola (Xoc) efficacy with an EC₅₀ (half-maximal effective concentration) value of 30.6 μg/mL, over twofold more active than control agent bismerthiazol (BMT). Additionally, compound 5B14 had a good antibacterial effect against the phytopathogen Xanthomonas axonopodis pv. citric (Xac) with EC₅₀ = 34.5 μg/mL, significantly better than control agent BMT (71.5 μg/mL). The anti-Xoc mechanistic studies showed that compound 5A26 exerted its antibacterial efficacy by increasing the permeability of bacterial membrane, decreasing the content of extracellular polysaccharides, and triggering morphological changes of bacterial cells.

Investigation of the Effects of Difluorinated Curcumin on Glycemic Indices in Streptozotocin-Induced Diabetic Rats

BACKGROUND

Curcumin is an antioxidant agent that improves glycemia in animal models of diabetes. Clinically curcumin use is limited due to poor solubility, weak absorption, and low bioavailability; therefore, this study to investigate the effects of curcumin's analog, difluorinated curcumin (CDF), on fasting blood glucose (FBG), oral glucose tolerance test (OGTT), and insulin tolerance test (ITT), in streptozotocin (STZ)-induced diabetic rats was undertaken.

METHODS

STZ-induced diabetes rats were randomly assigned to six groups (7 rats per group). They were treated daily by oral gavage with curcumin (200 and 100 mg/kg/day), CDF (200 and 100 mg/kg/day), and metformin (200 mg/kg/day) as a positive control group, for 4 weeks. Two diabetic control (DC) and normal control (NC) groups (non-diabetic rats) received normal saline and citrate buffer, respectively. FBG was measured at the beginning and end of the treatment (Day 0 and week 4) and OGTT and ITT were performed to determine glucose tolerance and insulin sensitivity.

RESULTS

Cur100, CDF 100, and CDF200 significantly decreased FBG levels after 4 weeks oral administration by -34% (-150 mg/dL ± 70, p = 0.02), -36% (123 mg/dL ±67, p < 0.04), and - 40% (-189 mg/dL ± 91, p = 0.03), respectively. Glucose sensitivity by OGTT showed a significant improvement in glucose tolerance ability in all treated groups compared with DC group. ITT demonstrated that insulin response improved significantly in Cur100 and CDF 200 groups.

CONCLUSION

Overall, CDF improved glucose tolerance and insulin sensitivity, while reducing FBG compared to curcumin, suggesting that curcumin analogs may have therapeutic utility in diabetes.

p-Trifluoromethyl- and p-pentafluorothio-substituted curcuminoids of the 2,6-di[(E)-benzylidene)]cycloalkanone type: Syntheses and activities against Leishmania major and Toxoplasma gondii parasites

A series of the title curcuminoids with structural variance in the heteroatom of the cycloalkanone and the p-substituents of the phenyl rings were tested for their activities against Leishmania major and Toxoplasma gondii parasites. The majority of them showed high activities against both parasite forms with EC₅₀ values in the sub-micromolar concentration range. Bis(p-pentafluorothio)-substituted 3,5-di[(E)-benzylidene]piperidin-4-one 1b was not just noticeable antiparasitic, but also exhibited a considerable selectivity for L. major promastigotes over normal Vero cells. While derivatives differing only in the p-phenyl substituents being CF₃ or SF₅ showed similar antiparasitic activities, the cyclic ketone hub was more decisive both for the anti-parasitic activities and the selectivities for the parasites vs. normal cells. QSAR calculations confirmed the observed structure-activity relations and suggested structural variations for a further improvement of the antiparasitic activity. Docking studies based on DFT calculations revealed L. major pteridine reductase 1 as a likely molecular target protein of the title compounds.

Crystal structure and anti-inflammatory activity of (3E,5E)-1-((4-chlorophenyl)sulfonyl)-3,5-bis(4-fluorobenzylidene)piperidin-4-one-dichloromethane (1/1), C26H20Cl3F2NO3S

C26H20Cl3F2NO3S, triclinic, P1̄ (no. 2), a = 8.6281(7) Å, b = 11.3695(9) Å, c = 14.3529(11) Å, α = 68.166(7)°, β = 80.707(7)°, γ = 71.169(7)°, V = 1235.65(19) Å3, Z = 2, R gt(F) = 0.0564, wR ref(F 2) = 0.1376, T = 100.00(10) K.

Crystal structure and anti-inflammatory activity of (3E,5E)-3,5-bis(4-fluorobenzylidene)-1-((4-fluorophenyl)sulfonyl)piperidin-4-one-dichloromethane (1/1), C26H20Cl2F3NO3S

C26H20Cl2F3NO3S, triclinic, P1̄ (no. 2), a = 8.5616(4) Å, b = 11.6052(6) Å, c = 14.1451(8) Å, α = 66.617(6)°, β = 82.391(4)°, γ = 69.072(4)°, V = 1204.85(12) Å3, Z = 2, R gt(F) = 0.0460, wR ref(F 2) = 0.1206, T = 100.00(10) K.

Synthesis, pharmacological profile and 2D-QSAR studies of curcumin-amino acid conjugates as potential drug candidates

A series of curcumin bis-conjugates 3a-q, 5a-k and 6a-k were synthesized in good yields utilizing an optimized reaction condition. We explored the effect of different amino acids and protecting groups on biological activities of curcumin. The conjugates were screened for anti-inflammatory, analgesic and antimicrobial properties. Some of the conjugates showed promising biological observations with a potency comparable with the standard references. The variations in biological properties concerning different amino acids and protecting groups are interesting observations. Effects of the synthesized conjugates on splenocytes and the production of nitric oxide by lipopolysaccharide-stimulated peritoneal macrophages are correlated with the observed anti-inflammatory properties. We have also established the safety profile of the most active conjugates. Robust 2D-QSAR studies supported and validated biological data.

Crystal structure and anti-inflammatory activity of (3E,5E)-3-(2-fluorobenzylidene)-1-((4-acetamidophenyl)sulfonyl)-5-(pyridin-3-ylmethylene)piperidin-4-one-methanol-hydrate (2/1/1), C53H50F2N6O10S2

C53H50F2N6O10S2, monoclinic, P21/n (no. 14), a = 15.088(5) Å, b = 23.560(9) Å, c = 15.401(6) Å, β = 112.254(5)°, V = 5067(3) Å3, Z = 4, R gt(F) = 0.0509, wR ref(F 2) = 0.1336, T = 298(2) K.

Synthesis of novel 4-Boc-piperidone chalcones and evaluation of their cytotoxic activity against highly-metastatic cancer cells

In this study, six curcuminoids containing a tert-butoxycarbonyl (Boc) piperidone core were successfully synthesized, five of them are novel compounds reported here for the first time. These compounds were prepared through an aldolic condensation by adding tetrahydropyranyl-protected benzaldehydes or substituted benzaldehyde to a reaction mixture containing 4-Boc-piperidone and lithium hydroxide in an alcoholic solvent. A 44-94% yield was obtained supporting the developed methodology as a good strategy for the synthesis of 4-Boc-piperidone chalcones. Cytotoxic activity against LoVo and COLO 205 human colorectal cell lines was observed at GI₅₀ values that range from 0.84 to 34.7 μg/mL, while in PC3 and 22RV1 human prostate cancer cell lines, GI₅₀ values ranging from 17.1 to 22.9 μg/mL were obtained. Results from biochemical assays suggest that the cytotoxicity of the 4-Boc-piperidone chalcones can be linked to their ability to induce apoptosis, decrease the activity of NFκB and cellular proliferation. Our findings strongly support the potential of Boc-piperidone chalcones as novel cytotoxic agents against highly-metastatic cancer cells.

Novel Curcumin Inspired Antineoplastic 1-Sulfonyl-4-Piperidones: Design, Synthesis and Molecular Modeling Studies

Background:

Curcumin is a well-known example of plant origin exhibiting promising diverse biological properties such as, anti-inflammatory and antitumor as well as poor pharmacokinetic/pharmacodynamic properties. This is why effective agents based on its chemical scaffold were explored.

Methods:

A set of 3,5-bis(ylidene)-1-(alkylsulfonyl)piperidin-4-ones were synthesized in excellent yield (80- 96%) through dehydrohalogenation reaction of 3,5-bis(ylidene)-4-piperidinones with the corresponding alkane sulfonyl chloride in the presence of triethylamine. Antiproliferative properties of the synthesized compounds (dienone/curcumin inspired analogues) were studied by the standard MTT technique.

Results:

Most of the synthesized compounds revealed antiproliferative properties against HCT116 (colon) and A431 (skin/squamous) cancer cell lines with IC50 values at sub-micromolar level. Compound 36 also exhibited potency against MCF7 (breast) and A549 (lung) cancer cell lines (IC50 = 2.23, 4.27µM, respectively) higher than that of the reference standards (IC50 = 3.15, 5.93µM for 5-fluorouracil and doxorubicin against MCF7 and A549 cell lines, respectively). Cytotoxic properties of the synthesized compounds against non-cancer RPE1 cell line supported the safety profile of the effective agents against normal cells. Molecular modeling (3Dpharmacophore and 2D-QSAR) studies validated the observed bio-properties and explained the parameters governing activity. Inhibitory properties of compounds 27 and 29 (representative examples of the promising antiproliferative agents synthesized) supported their mode of action against topoisomerase IIα

Conclusion:

The synthesized scaffold is a promising antitumor agent (with special selectivity against colon and skin/squamous cancer cell lines) so, it can be considered for further investigation and development of highly effective hits/leads based on the computational models obtained.

Pharmaceutical and medicinal significance of sulfur (SVI)-Containing motifs for drug discovery: A critical review

Sulfur (S^VI) based moieties, especially, the sulfonyl or sulfonamide based analogues have showed a variety of pharmacological properties, and its derivatives propose a high degree of structural diversity that has established useful for the finding of new therapeutic agents. The developments of new less toxic, low cost and highly active sulfonamides containing analogues are hot research topics in medicinal chemistry. Currently, more than 150 FDA approved Sulfur (S^VI)-based drugs are available in the market, and they are widely used to treat various types of diseases with therapeutic power. This comprehensive review highlights the recent developments of sulfonyl or sulfonamides based compounds in huge range of therapeutic applications such as antimicrobial, anti-inflammatory, antiviral, anticonvulsant, antitubercular, antidiabetic, antileishmanial, carbonic anhydrase, antimalarial, anticancer and other medicinal agents. We believe that, this review article is useful to inspire new ideas for structural design and developments of less toxic and powerful Sulfur (S^VI) based drugs against the numerous death-causing diseases.

Synthesis of β-Ketoamide Curcumin Analogs for Anti-Diabetic and AGEs Inhibitory Activities

Two different series of novel β-ketoamide curcumin analogs enriched in biological activities have been synthesized. The synthesized compounds were screened for their in vitro anti-diabetic and AGEs inhibitory activities and exhibited potent to good anti-diabetic and AGEs inhibitory activities. The molecular docking study was also performed with the α-amylase enzyme.

Eliminating the heart from the curcumin molecule: monocarbonyl curcumin mimics (MACs)

Curcumin is a natural product with several thousand years of heritage. Its traditional Asian application to human ailments has been subjected in recent decades to worldwide pharmacological, biochemical and clinical investigations. Curcumin’s Achilles heel lies in its poor aqueous solubility and rapid degradation at pH ~ 7.4. Researchers have sought to unlock curcumin’s assets by chemical manipulation. One class of molecules under scrutiny are the monocarbonyl analogs of curcumin (MACs). A thousand plus such agents have been created and tested primarily against cancer and inflammation. The outcome is clear. In vitro, MACs furnish a 10–20 fold potency gain vs. curcumin for numerous cancer cell lines and cellular proteins. Similarly, MACs have successfully demonstrated better pharmacokinetic (PK) profiles in mice and greater tumor regression in cancer xenografts in vivo than curcumin. The compounds reveal limited toxicity as measured by murine weight gain and histopathological assessment. To our knowledge, MAC members have not yet been monitored in larger animals or humans. However, Phase 1 clinical trials are certainly on the horizon. The present review focuses on the large and evolving body of work in cancer and inflammation, but also covers MAC structural diversity and early discovery for treatment of bacteria, tuberculosis, Alzheimer’s disease and malaria.

Oxygen as single oxidant for two steps: base-free one-pot Pd(ii)-catalyzed alcohol oxidation & arylation to halogen-intact β-aryl α,β-enones

Using oxygen as the sole oxidant for two steps, we developed a new method to synthesize β-aryl α,β-enones by fine-tuning the Pd(ii)-catalyzed oxidation of allyl alcohol to subsequent arylation with arylboronic acids, arylboronic ester and aryltrifluoroborate salt.

C5-curcuminoid-dithiocarbamate based molecular hybrids: synthesis and anti-inflammatory and anti-cancer activity evaluation

The C5-curcumin-dithiocarbamate analogues were synthesized in search of new molecules with anti-proliferation potential against cancer cells. These new compounds demonstrated higher anti-proliferation and anti-inflammatory activity against cancer cell lines in comparison to curcumin.