Synthesis and antitumor activity of new tetrahydrocurcumin derivatives via click reaction

Synthesis, Anticancer Activity, and Molecular Docking of New 1,2,3-Triazole Linked Tetrahydrocurcumin Derivatives

Cancer is one of the deadliest diseases to humanity. There is significant progress in treating this disease, but developing some drugs that can fight this disease remains a challenge in the field of medical research. Thirteen new 1,2,3-triazole linked tetrahydrocurcumin derivatives were synthesized by click reaction, including a 1,3-dipolar cycloaddition reaction of tetrahydrocurcumin baring mono-alkyne with azides in good yields, and their in vitro anticancer activity against four cancer cell lines, including human cervical carcinoma (HeLa), human lung adenocarcinoma (A549), human hepatoma carcinoma (HepG2), and human colon carcinoma (HCT-116) were investigated using MTT(3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetraz-olium bromide) assay. The newly synthesized compounds had their structures identified using NMR HRMS and IR techniques. Some of prepared compounds, including compounds 4g and 4k, showed potent cytotoxic activity against four cancer cell lines compared to the positive control of cisplatin and tetrahydrocurcumin. Compound 4g exhibited anticancer activity with a IC50 value of 1.09 ± 0.17 μM against human colon carcinoma HCT-116 and 45.16 ± 0.92 μM against A549 cell lines compared to the positive controls of tetrahydrocurcumin and cisplatin. Moreover, further biological examination in HCT-116 cells showed that compound 4g can arrest the cell cycle at the G1 phase. A docking study revealed that the potential mechanism by which 4g exerts its anti-colon cancer effect may be through inhabiting the binding of APC-Asef. Compound 4g can be used as a promising lead for further exploration of potential anticancer agents.

Semi-synthesis of phenolic-amides and their cytotoxicity against THP-1, HeLa, HepG2 and MCF-7 cell lines

In the present study, we derivatized several hydroxycinnamic and hydroxybenzoic acids to phenolic amides (PAMs) via one step BOP mediated amide coupling reactions. Fifteen PAMs were synthesized in >40% yields and were screened for their cytotoxic activities against four cancer cell lines: THP-1 (leukaemia), HeLa (cervical), HepG2 (liver), and MCF-7 (breast), in comparison to 5-flurouracil (5-FU). Four amides showed IC50 ranging from 5 to 55 µM against all four cell lines. In contrast, tetradecyl-gallic-amide (13) affected only THP-1 leukaemia cells with IC50 of 3.08 µM. The activities of these compounds support the promise of phenolic amides as anticancer agents.

Synthesis and antifungal activity of hexahydropyrrolidoindole alkaloids

Twenty-one hexahydropyrrolidoindole alkaloids were designed and synthesised via acylation reaction at the 3-N position from the commercially available indole-3-acetonitrile as the starting material in excellent yields. The effects of all target compounds against Verticillium dahlia, Fusarium oxysperium sp., Cytospora juglandis, Aspergillu sflavu, Aspergillus niger and Fusarium oxysporum were determined. The results of bioassays indicated that the majority of tested compounds displayed comparable or better in vitro bioactivity than the positive control. Notably, compounds 8 and 17 revealed potent activity against C. juglandis and A. sflavu, both with the same minimum inhibitory concentration value of 1.9 µg mL-1, which has fungicidal activity far exceeded that of amphotericin B and chlorothalonil.

Synthesis and cytotoxic activity of ethyl ferulate derivatives as potent anti-inflammatory agents

While a range of pharmacological agents are currently used to alleviate inflammation, the clinical administration of many of these anti-inflammatory drugs is associated with high rates of adverse side effects that make them poorly suited to long-term use. Therefore, there is a critical need for the development of novel anti-inflammatory agents. Natural compounds and derivatives like ethyl ferulate have risen to prominence as a foundation for many drug discovery efforts owing to their structural diversity and wide-ranging biological activities. In the present study, 24 ethyl ferulate derivatives were synthesized. Their anti-inflammatory activity was evaluated in vitro using RAW264.7 cells and CCK-8, ELISA, and Western blotting assays. These analyses revealed that most of the synthesized compounds exhibited moderate to high anti-inflammatory activities. In particular, c10 and c23 exerted more pronounced activity than ethyl ferulate or dexamethasone with respect to the suppression of tumour necrosis factor-α production by RAW264.7 cells through the targeting of the NF-κB and MAPK signalling pathways, suggesting that these compounds warrant further investigation.

Podophyllotoxin: Recent Advances in the Development of Hybridization Strategies to Enhance Its Antitumoral Profile

Podophyllotoxin is a naturally occurring cyclolignan isolated from rhizomes of Podophyllum sp. In the clinic, it is used mainly as an antiviral; however, its antitumor activity is even more interesting. While podophyllotoxin possesses severe side effects that limit its development as an anticancer agent, nevertheless, it has become a good lead compound for the synthesis of derivatives with fewer side effects and better selectivity. Several examples, such as etoposide, highlight the potential of this natural product for chemomodulation in the search for new antitumor agents. This review focuses on the recent chemical modifications (2017-mid-2023) of the podophyllotoxin skeleton performed mainly at the C-ring (but also at the lactone D-ring and at the trimethoxyphenyl E-ring) together with their biological properties. Special emphasis is placed on hybrids or conjugates with other natural products (either primary or secondary metabolites) and other molecules (heterocycles, benzoheterocycles, synthetic drugs, and other moieties) that contribute to improved podophyllotoxin bioactivity. In fact, hybridization has been a good strategy to design podophyllotoxin derivatives with enhanced bioactivity. The way in which the two components are joined (directly or through spacers) was also considered for the organization of this review. This comprehensive perspective is presented with the aim of guiding the medicinal chemistry community in the design of new podophyllotoxin-based drugs with improved anticancer properties.

Synthesis, molecular docking studies of formononetin derivatives as potent Bax agonists for anticancer activity

Formononetin as a Bax agonist exhibits anticancer effects. To identify novel Bax agonist, 18 new structurally modified formononetin derivatives were synthesised and their anticancer activities were evaluated in the A549 and Beas-2b cell lines. The results indicated that 7a elicited the most potent inhibitory effect against the A549 cell line, with an IC50 value of 0.87 μM, and no obvious toxicity to Beas-2b cells. These results indicated that 7a was 40-fold and 6.94-fold more efficacious than Formononetin and Doxorubicin, respectively. Additionally, western blot and immunofluorescence assays demonstrated that 7a downregulated the protein expression of Bcl-2 and upregulated the expressions of Bax to promote A549 apoptosis, the obtained results also suggested that 7a had the potential to be developed into a lead compound that can be applied in the prevention and treatment of lung cancer.

Design, synthesis, and biological activity of 9-O-cinnamoylberberines as novel lipid-lowering agents

Berberine possesses a wide spectrum of lipid regulation, and yet it has poor physicochemical property and cytotoxicity as a drug candidate. In order to alleviate the problems, a total of twenty-one 9-O-cinnamoylberberines and twenty 9-O-cinnamoyltetrahydroberberines were designed, synthesized, and evaluated by in vitro cell viability experiment and four classical lipid-lowering assays involving with total cholesterol, triglyceride, low density lipoprotein cholesterol, and high density lipoprotein cholesterol. A structure-activity relationship study of these compounds resulted in the discovery of two promising candidate molecules (5p and 7u). Compound 5p displayed the most potent inhibitory effect for TG formation, with the inhibitory rates of 40.5% and 76.8% in 3T3-L1 cells and HepG2 cells, respectively. Compound 7u exhibited the most promoting activity for the production of HDLC, with the increasing rates of 52.6% and 70.5% in both models, respectively. These two attractive compounds can be further investigated as new lipid-lowering agents in follow-up researches.

Glyco-conjugation in 3-β-anhydroicaritine

A convenient method has been developed for the glycol-conjugation in 3-position of β-anhydroicaritine in a reasonable yield. The structure of the 3-glycosylated β-anhydroicaritine derivatives was confirmed to be correct by ¹H NMR, ¹³C NMR and HRMS spectrum. These compounds are less soluble than icaritin, but more soluble than icariside II in CCl₄. The screening results showed that compounds 12h, 12i and 12j had higher cytotoxicity to HepG2 and MCF-7 at a concentration of 50 μM.

Synthesis and anti-proliferative activity of dehydroabietinol derivatives bearing a triazole moiety

In search of more efficacious antitumor agents, a series of novel dehydroabietinol derivatives containing a triazole moiety was synthesized, and evaluated for cytotoxicity against four human cancer cell lines. Many exhibited superior cytotoxic profiles compared to the parent molecule, dehydroabietic acid. In particular, compounds 5g, 5i and 5j exhibited promising cytotoxicity with IC50 values ranging from 4.84 to 9.62 μM against all the test cell lines. Cell clone formation and migration tests of compound 5g showed that it not only effectively inhibited the formation of MGC-803 cell colonies but also inhibited the MGC-803 cell migration and invasion. Additionally, the preliminary pharmacological mechanism indicated compound 5g induced apoptosis, arrested the mitotic process at the G0/G1 phase of the cell cycle, reduced the mitochondrial membrane potential, and increased the intracellular ROS and Ca2+ levels.

Design, synthesis and antibacterial evaluation of a novel class of tetrahydrobenzothiophene derivatives

In this study, a new series of tetrahydrobenzothiophene derivatives have been designed. Newly designed molecules have been synthesized through a medicinal chemistry route, and their characterization was done by using NMR and HR-MS techniques. Biological evaluation of the synthesized compounds has been done on Gram-negative and Gram-positive bacteria. The marketed antibiotics such as ciprofloxacin and gentamicin were used as controls. The in vitro evaluation results have shown that most of the targeted compounds exhibit good potency in inhibiting the growth of bacteria, including E. coli (MIC: 0.64-19.92 μM), P. aeruginosa (MIC: 0.72-45.30 μM), Salmonella (MIC: 0.54-90.58 μM) and S. aureus (MIC: 1.11-99.92 μM). In particular, compound 3b showed excellent activity with an MIC value of 1.11 μM against E. coli, 1.00 μM against P. aeruginosa, 0.54 μM against Salmonella, and 1.11 μM against S. aureus. From the results, a promising lead compound was identified for future development.

Synthesis and Cytotoxic Activity of Novel Ergosterol Peroxide Derivatives with Acrylate or Propionate Side Chain

A series of novel ergosterol peroxide derivatives with acrylate or propionate side chain were synthesized. All compounds 3a-n were evaluated for their cytotoxicity against four kinds of human carcinoma cell lines (HepG2, MCF-7, HCT-116, and A549). Most of the derivatives displayed stronger cytotoxicity than ergosterol peroxide parent. Among them, compound 3h with the highest potency against HepG2 cell line (IC50  =  2.70 μM), which was 7.47-fold more efficacious than ergosterol peroxide. The results suggested that the introduction of acrylate or propionate side chain at C-3 position of ergosterol peroxide is beneficial to enhance its cytotoxic activity. Compound 3h has potential to become a novel anti-tumor agent through further structural modification.

Antibacterial and Antiviral Properties of Tetrahydrocurcumin-Based Formulations: An Overview of Their Metabolism in Different Microbiotic Compartments

In this review, the basic metabolic characteristics of the curcuminoid tetrahydrocurcumin (THC) at the level of the intestinal microbiota were addressed. Special attention was given to the bactericidal effects of one of the THC-phospholipid formulations, which has shown greater bioavailability and activity than pure THC. Similarly, quinoline derivatives and amino acid conjugates of THC have also shown antibacterial effects in the gut. The microbial effect of pure THC is particularly pronounced in pathophysiological conditions related to the function of the intestinal microbiota, such as type II diabetes. Furthermore, the antiviral characteristics of Cur compared to those of THC are more pronounced in preventing the influenza virus. In the case of HIV infections, the new microemulsion gel formulations of THC possess high retention during preventive application in the vagina and, at the same time, do not disturb the vaginal microbiota, which is critical in maintaining low vaginal pH. Based on the reviewed literature, finding new formulations of THC which can increase its bioavailability and activity and emphasize its antibacterial and antiviral characteristics could be very important. Applying such THC formulations in preventing and treating ailments related to the microbiotic compartments in the body would be beneficial from a medical point of view.

Morpholine substituted quinazoline derivatives as anticancer agents against MCF-7, A549 and SHSY-5Y cancer cell lines and mechanistic studies

A series of morpholine substituted quinazoline derivatives have been synthesized and evaluated for cytotoxic potential against A549, MCF-7 and SHSY-5Y cancer cell lines. These compounds were found to be non-toxic against HEK293 cells at 25 μM and hence display anticancer potential. In these series compounds, AK-3 and AK-10 displayed significant cytotoxic activity against all the three cell lines. AK-3 displayed IC50 values of 10.38 ± 0.27 μM, 6.44 ± 0.29 μM and 9.54 ± 0.15 μM against A549, MCF-7 and SHSY-5Y cancer cell lines. Similarly, AK-10 showed IC50 values of 8.55 ± 0.67 μM, 3.15 ± 0.23 μM and 3.36 ± 0.29 μM against A549, MCF-7 and SHSY-5Y, respectively. In the mechanistic studies, it was found that AK-3 and AK-10 inhibit the cell proliferation in the G1 phase of the cell cycle and the primary cause of death of the cells was found to be through apoptosis. Thus, morpholine based quinazoline derivatives have the potential to be developed as potent anticancer drug molecules.

New ent-kaurene and germacrene derivatives from Mesona procumbens Hemseley and their biological activity

Mesona procumbens Hemseley is a well-known traditional herbal medicine used for heat-related ailments. In Taiwan, boiled extracts of M. procumbens are also used as desserts called grass jelly. In this study, the hexane extract from 75% EtOH of M. procumbens showed potent activities on inhibition of E. coli β-glucuronidase (eβG) and NO production and cytotoxicity against MCF-7 and HepG2 cancer cell lines. Furthermore, using various flash columns and HPLC chromatography on the bioactive layer led to the isolation of twelve compounds (1-12), including a new ent-kaurene, mesokaurol A (1), and a new germacrene derivative, mesogermapene A (2). Their structures were elucidated by extensive spectroscopic analyses, especially 2 D NMR and mass data. Biological assays showed that compound 9 (linolenic acid) had specific activity on inhibition of eβG (68.27%) at 100 µg/mL but was non-inhibitory to human β-glucuronidase. Compound 1 possessed significant cytotoxicity against MCF-7 (EC₅₀ = 9.76 µM) and HepG2 (EC₅₀ = 8.64 µM) cancer cell lines.

First report on the synthesis and structural studies of trans-Phakellistatin 18: a rotamer of marine natural product phakellistatin 18

Phakellistatin peptides from marine organisms are the sources of proline-rich cyclic peptides with reported significant antitumor activities. Phakellistatin 18 (1), reported from marine sponge Phakellia fusca, contains three proline-peptide linkages in cis form. We attempted the total synthesis of natural product 1 through solution-phase macrocyclization approach, as a result, the synthetic cyclic peptide 2 was obtained as a rotamer of natural product having all three proline residues in trans-conformation. Here, we describe the synthesis, structural, and cytotoxicity studies of trans-Phakellistatin 18 (2), and its analog [Ala^1,3,6]-Phakellistatin 18 (3). Detailed NMR studies were carried out to characterize the synthesized peptides, and anti-cancer screening was performed by using MTT assay. The synthetic trans-Phakellistatin 18 (2) (IC₅₀=67.5 ± 2.938 µM) showed comparable cytotoxicity against HepG2 cancer cell line with standard drug doxorubicin (IC₅₀=63.88 ± 6.48 µM). Here, the first synthetic and structural studies on trans-Phakellistatin 18 (2), and its anticancer screening against HepG2 cell line was reported.