Inhibitory activity of synthesized acetylated Procyanidin B1 analogs against HeLa S3 cells proliferation.

Syuhei Okamoto,Syoma Doi,Sayaka Ishihara,Noriyuki Nakajima,Takashi Kawasaki,Yusuke Higashino,Kota Harui,Akiko Saito,Taisuke Okamoto

doi:10.3390/molecules19021775

Abstract

Proanthocyanidins, also known as condensed tannins and/or oligomeric flavonoids, occur in many edible plants and have various interesting biological activities. Previously, we reported a synthetic method for the preparation of various procyanidins in pure form and described their biological activities. Here, we describe the synthesis of procyanidin B1 acetylated analogs and discuss their inhibition activities against HeLa S3 cell proliferation. Surprisingly, the lower-unit acetylated procyanidin B1 strongly inhibited the proliferation of HeLa S3 cells. This molecule showed much stronger inhibitory activity than did epigallocatechin-3-O-gallate (EGCG), green tea polyphenol, and dimeric compounds that included EGCG as a unit. This result suggests that the phenolic hydroxyl groups of the upper-units in flavan-3-ols are important for their inhibitory activity against cancer cell proliferation and that a hydrophobic lower unit dimer enhances this activity.

Highlights

There is currently a great interest in research involving compounds having strong anti-oxidation activities and superior radical scavenging abilities
Our synthetic methodologies are applicable to various procyanidin oligomers such as the
Compounds 14 and 15, which have hydrophobic lower-units, showed strong inhibitory activity against cell proliferation. These results suggest that the biological activities of proanthocyanidins depend on the number of phenolic hydroxyl groups and on various factors such as their structures, hydrophobic properties, and hydrophilic properties

Summary

Introduction

There is currently a great interest in research involving compounds having strong anti-oxidation activities and superior radical scavenging abilities. Surface plasmon resonance has shown the 67-kDa laminin receptor, which is widely expressed at high levels in cancer cell membranes, to be one of the receptors of EGCG [2]. This finding is evidence supporting the selective cytotoxic activity of EGCG against cancer cells. Proanthocyanidins, which are condensed tannins or oligomeric flavonoids [3,4] are known to be extremely strong antioxidants. Research on these compounds has become increasingly important because of their various strong biological activities. HeLa S3 cell proliferation inhibitory activity of a hydrophobic procyanidin B1 analogue in which the lower-unit was acetylated

Results and Discussion

General

Inhibitory Activity of Cell Proliferation

Conclusions