Novel enmein-type diterpenoid hybrids coupled with nitrogen mustards: Synthesis of promising candidates for anticancer therapeutics.

Abstract

Natural derived enmein-type diterpenoids exert cytotoxicity against a wide range of human cancer cells. Yet their medicinal applications are hindered by insufficient potency for chemotherapy. Hence, a series of novel enmein-type diterpenoid hybrids coupled with nitrogen mustards were designed and synthesized to increase antitumor efficacy while reducing systemic toxicity. Most conjugates exhibited stronger antiproliferative activities than parent diterpenoids and nitrogen mustards, especially for multidrug-resistant tumor cell line Bel-7402/5-FU. Among them, compound E2 showed the most potent inhibitory activities in human leukemia HL-60 cells, human prostate cancer PC-3 cells, human liver cancer Bel-7402 cells and drug-resistant human liver cancer Bel-7402/5-FU cells with IC50 values of 7.83 μM, 3.97 μM, 0.77 μM and 2.07 μM, respectively. Additionally, high selectivity with selectivity index over 130 was also observed from cytotoxic evaluation between L-02 human normal liver cells and Bel-7402 malignant liver cells. Further studies on mechanism of action indicated that E2 induced both apoptosis and G1 phase cell cycle arrest in Bel-7402 hepatoma cells. Moreover, the dysfunction in mitochondrial pathway was also involved in E2 initiated apoptotic activation, which entailed the loss of mitochondrial membrane potential followed by upregulating the bax/bcl-2 ratio and increasing the expression of cytochrome c, p53, caspase-3 and -9. Overall, E2 has the potential to emerge as a promising drug candidate for cancer therapy.

• Authors: Xiang Gao, Jia Li, Mingying Wang, Shengtao Xu, Weiwei Liu, Linghe Zang, Zhanlin Li, Huiming Hua, Jinyi Xu, Dahong Li
• Journal: European journal of medicinal chemistry (Eur J Med Chem) Vol. 146 Pg. 588-598 (Feb 25 2018) ISSN: 1768-3254 [Electronic] France
• PMID: 29407983 (Publication Type: Journal Article)
• Copyright: Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Chemical References

• Antineoplastic Agents
• Diterpenes
• enmein
• Mechlorethamine

Topics

• Antineoplastic Agents (chemical synthesis, chemistry, pharmacology)
• Apoptosis (drug effects)
• Cell Line, Tumor
• Cell Proliferation (drug effects)
• Diterpenes (chemistry, pharmacology)
• Dose-Response Relationship, Drug
• Drug Screening Assays, Antitumor
• Humans
• Mechlorethamine (chemistry, pharmacology)
• Membrane Potential, Mitochondrial (drug effects)
• Molecular Structure
• Structure-Activity Relationship