Synthesis and evaluation of new sterol derivatives as potential antitumor agents

Recent advances on quinoxalines as target-oriented chemotherapeutic anticancer agents through apoptosis

The current review outlines all possible recent synthetic platforms to quinoxaline derivatives and the potent stimulated apoptosis mechanisms targeted by anticancer therapies. The currently reported results disclosed that quinoxaline derivatives had promising anticancer potencies against a wide array of cancer cell lines, better than the reference drugs, through target inhibition. This review summarizes some potent quinoxaline derivatives with their synthesis strategies and their potential activities against various molecular targets. Quinoxalines can be considered an important scaffold for apoptosis inducers in cancer cells through inhibiting some molecular targets, so they can be further developed as target-oriented chemotherapeutics.

Quinoxaline derivatives: Recent discoveries and development strategies towards anticancer agents

Cancer is a leading cause of death and a major health problem worldwide. While many effective anticancer agents are available, most drugs currently on the market are not specific, raising issues like the common side effects of chemotherapy. However, recent research hold promises for the development of more efficient and safer anticancer drugs. Quinoxaline and its derivatives are becoming recognized as a novel class of chemotherapeutic agents with activity against different tumors. The present review compiles and discusses studies concerning the therapeutic potential of the anticancer activity of quinoxaline derivatives, covering articles published between January 2018 and January 2023.

The Biological Fate of a Novel Anticancer Drug Candidate TNBG-5602: Metabolic Profile, Interaction with CYP450, and Pharmacokinetics in Rats

TNBG-5602, a novel anticancer drug candidate, may induce the expression of PPARγ, causing targeted lipotoxicity in cancer tissues. In this study, the in vivo metabolism in rats, in vitro metabolism in recombinant cytochromes, molecular docking for the CYP binding site, and pharmacokinetics in rats were explored to better understand TNBG-5602's in vivo fate and behavior. Thirteen metabolites were identified using a high-resolution mass spectrometry method, and metabolizing pathways of TNBG-5602 were proposed. Results suggest that TNBG-5602 could be metabolized by CYP450s, while CYP2D6 may play an important role in its in vivo metabolism. The main metabolizing sites of TNBG-5602 are the amino group on the side chain and rings A and E in the molecule. TNBG-5602 is a potent CYP2D6 inhibitor, with an IC₅₀ value of 2.52 μM. An interaction responsible for its metabolism is formed by the NH on the side chain bonding with the ASP301 on the CYP2D6. The pharmacokinetics in rats after a single intravenous administration were fitted to a two-compartment model. The clearance was 0.022 L min^-1, and the elimination half-life was 710.9 min. The distribution volume of the peripheral compartment was 1.88-fold that of the central compartment, while the K₁₂ was 1.5-fold that of K₂₁. In conclusion, these studies have not only revealed the metabolizing pathways of TNBG-5602 using in vivo and in vitro methodology, but they have also provided the pharmacokinetic characteristics of TNBG-5602 in rats. The results suggest that TNBG-5602 has good drug developability in terms of pharmacokinetic behaviors.

Crystal structure of 9-methoxy-2,3,4,4a,5,6-hexahydro-1H-pyrido [1′,2′:1,6]pyrazino[2,3-b]quinoxaline, C15H18N4O

C15H18N4O, triclinic, P 1 ‾ $P\overline{1}$ (no. 2), a = 6.7562(5) Å, b = 9.5520(6) Å, c = 11.4227(8) Å, α = 97.206(5)°, β = 102.335(6)°, γ = 108.614(7)°, V = 667.39(9) Å3, Z = 2, R gt (F) = 0.0480, wR ref (F 2) = 0.1388, T = 150 K.

Crystal structure of 2-methoxy-4b,5,14,15-tetrahydro-6H-isoquinolino[2′,1′:1,6] pyrazino[2,3-b]quinoxaline, C19H18N4O

C19H18N4O, monoclinic, P21/c (no. 14), a = 11.3744(16) Å, b = 13.7367(15) Å, c = 11.208(2) Å, β = 118.51(2)°, V = 1538.9(5) Å3, Z = 4, R gt (F) = 0.0494, wR ref (F 2) = 0.1327, T = 100(2) K.

Tetrazanbigen Derivatives as Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) Partial Agonists: Design, Synthesis, Structure-Activity Relationship, and Anticancer Activities

Tetrazanbigen (TNBG) is a novel sterol isoquinoline derivative with poor water solubility and moderate inhibitory effects on human cancer cell lines via lipoapoptosis induction. Herein, we developed a series of novel TNBG analogues with improved water solubility and antiproliferative activities. The CCK-8 assay enabled us to identify a novel compound, 14g, which strongly inhibited HepG2 and A549 cell growth with IC₅₀ values of 0.54 and 0.47 μM, respectively. The anticancer effects might be explained by the partial activation and upregulation of PPARγ expression, as indicated by the transactivation assay and western blotting evaluation. Furthermore, the in vitro antiproliferative activity was verified in an in vivo xenograft model in which 14g strongly reduced tumor growth at a dose of 10 mg/kg. In line with these positive observations, 14g exhibited an excellent water solubility of 31.4 mg/mL, which was more than 1000-fold higher than that of TNBG (4 μg/mL). Together, these results suggest that 14g is a promising anticancer therapeutic that deserves further investigation.

Synthesis and biological evaluation of substituted pyrrolidines and pyrroles as potential anticancer agents

A series of polysubstituted pyrrolidines obtained via ruthenium-catalyzed cascade cyclization of diazo pyruvates and anilines as well as their corresponding pyrrole analogs obtained via dehydration were evaluated for their antiproliferation activities. Pyrrolidines 3h and 3k showed good proliferation inhibitory effects toward 10 cancer cell lines with IC₅₀ values ranging from 2.9 to 16 μM. Furthermore, pyrrolidine 3k induced cell cycle arrest at the G0/G1 phase and time- and dose-dependent cellular apoptosis in both HCT116 and HL60 cells, suggesting that this type of pyrrolidine structure might be a good candidate for future anticancer therapies.

Crystal structure of 3-fluoro-9-methoxy-4b,5,14,15-tetrahydro-6H-isoquinolino [2′,1′:1,6]pyrazino[2,3-b]quinoxaline, C19H17FN4O

C19H17FN4O, orthorhombic, Pbca (no. 61), a = 7.0607(2) Å, b = 18.4459(5) Å, c = 23.8955(7) Å, V = 3112.17(15) Å3, Z = 8, Rgt(F) = 0.0543, wRref(F2) = 0.1540, T = 100(2) K.

TNBG-5602, a novel derivative of quinoxaline, inhibits liver cancer growth via upregulating peroxisome proliferator-activated receptor γ in vitro and in vivo

Objectives

TNBG-5602 is a newly synthesized compound with an isoquinoline structure. In the present study, we demonstrated the anticancer effect of TNBG-5602 in in-vitro and in-vivo models and investigated its possible anticancer mechanism.

Methods

The antiproliferation effect of TNBG-5602 in vitro was evaluated in human liver cancer cell line QGY-7701. The acute toxicity of TNBG-5602 was evaluated in mice. The anticancer activity of TNBG-5602 in vivo was assessed in a xenograft model of human liver cancer cell line QGY-7701.

Key findings

The results of CCK-8 assay showed that TNBG-5602 can effectively inhibit the proliferation of liver cancer cells in vitro. The acute toxicity test in mice showed that the LD50 of TNBG-5602 was 172 mg/kg. In a xenograft liver cancer model, TNBG-5602 could remarkably inhibit the growth of tumours. During in-vitro and in-vivo studies, we noted that TNBG-5602 could induce lipid accumulation in cancer cells and tissues. Further study indicated that the anticancer effect of TNBG-5602 may be exerted through activating peroxisome proliferator-activated receptor γ (PPARγ) and downregulating proliferating cell nuclear antigen (PCNA).

Conclusions

Our results suggested that TNBG-5602 might exert potent anticancer activity through increasing the expression of PPARγ.