Dihydrochalcone Compounds Isolated from Crabapple Leaves Showed Anticancer Effects on Human Cancer Cell Lines.

Yun Xing,Zhiqin Zhou,Yuncong Yao,Xiaoxiao Qin

doi:10.3390/molecules201219754

Yun Xing, Zhiqin Zhou + Show 2 more

Open Access

https://doi.org/10.3390/molecules201219754

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Abstract

Seven dihydrochalcone compounds were isolated from the leaves of Malus crabapples, cv. “Radiant”, and their chemical structures were elucidated by UV, IR, ESI-MS, 1H-NMR and 13C-NMR analyses. These compounds, which include trilobatin (A1), phloretin (A2), 3-hydroxyphloretin (A3), phloretin rutinoside (A4), phlorizin (A5), 6′′-O-coumaroyl-4′-O-glucopyranosylphloretin (A6), and 3′′′-methoxy-6′′-O-feruloy-4′-O-glucopyranosyl-phloretin (A7), all belong to the phloretin class and its derivatives. Compounds A6 and A7 are two new rare dihydrochalcone compounds. The results of a MTT cancer cell growth inhibition assay demonstrated that phloretin and these derivatives showed significant positive anticancer activities against several human cancer cell lines, including the A549 human lung cancer cell line, Bel 7402 liver cancer cell line, HepG2 human ileocecal cancer cell line, and HT-29 human colon cancer cell line. A7 had significant effects on all cancer cell lines, suggesting potential applications for phloretin and its derivatives. Adding a methoxyl group to phloretin dramatically increases phloretin’s anticancer activity.

Highlights

Dihydrochalcones are a class of flavonoids characterized by a basic C6-C3-C6 backbone structure and the absence of a heterocyclic C ring
The leaves of Malus crabapples were extracted with 50% ethanol/water
The extract was subjected to column chromatography (CC) and preparative HPLC (PHPLC)

Summary

Introduction

Dihydrochalcones are a class of flavonoids characterized by a basic C6-C3-C6 backbone structure and the absence of a heterocyclic C ring. Dihydrochalcones (mainly phloridzin, sieboldin, trilobatin, and phloretin) represent the major flavonoid subgroup in plant tissues [3]. They are widely distributed in apple trees, especially in the leaves and immature fruits. Phloridzin, the most abundant phenolic compound in Malus plants [2,4,5], regulates apoptosis and alters gene expression to inhibit the growth of cancer cells. Crabapples belong to the genus Malus (Rosaceae) They are important ornamental plants widely distributed throughout the world. In this paper, we describe the isolation and structure of dihydrochalcone monomers from the Malus cultivar “Radiant” and provide evidence for the anticancer activities of these compounds, suggesting further investigations of their potential anti-tumor activities in animal models

Results and Discussion

In Vitro Cytotoxicity of the Seven Dihydrochalcone Monomer Compounds

A2 A3 A4 A5 A6 A7

Materials and Instruments

Purification of Dihydrochalcones from Crabapple “Radiant” Leaves

MS System and Conditions

Cancer Cell Growth Inhibition

Statistical Analysis

Conclusions