Abstract

Some derivatives of trans-anethole [1-methoxy-4-(1-propenyl)-benzene] (1) were synthesized, by introducing hydroxyl groups in the double bond of the propenyl moiety. Two types of reactions were performed: (i) oxymercuration/demercuration that formed two products, the mono-hydroxyl derivative, 1-hydroxy-1-(4-methoxyphenyl)-propane (2) and in lesser extent the dihydroxyl derivative, 1,2-dihydroxy-1-(4-methoxyphenyl)-propane (3) and (ii) epoxidation with m-chloroperbenzoic acid that also led to the formation of two products, the dihydroxyl derivative (3) and the correspondent m-chloro-benzoic acid mono-ester, 1-hydroxy-1(4-methoxyphenyl)-2-m-chlorobenzoyl-propane (4). The structures of these compounds were confirmed mainly by mass, IR, ¹H and ¹³C NMR spectral data. The activity of anethole and hydroxylated derivatives was evaluated using antioxidant, anti-inflammatory and gastroprotector tests. Compounds (2) and (3) were more active antioxidant agents than (1) and (4). In the anti-inflammatory assay, anethole showed lower activity than hydroxylated derivatives. Anethole and in lesser extent its derivatives 2 and 4 showed significant gastroprotector activity. All tested compounds do not alter significantly the total number of white blood cells.

Graphical abstract

Trans-Anethole (1) was used as starting material to synthesize the hydroxylated derivatives (2), (3) and (4) and their structures were confirmed by spectral data. Hydroxyl groups were introduced on the double bond of the side chain, using m-chloroperbenzoic acid (MCPBA) and via oxymercuration/demercuration reactions. Anethole (1) and compounds (2), (3) and (4) were submitted to antioxidant, anti-inflammatory and gastroprotector activity tests. Compounds (2) and (3) were more active as antioxidant and anti-inflammatory agents than (1) and (4). Anethole and in lesser extent its derivatives 2 and 4 showed significant gastroprotector activity. All tested compounds do not alter significantly the total number of white blood cells.

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Keywords: Anethole; Anti-inflammatory; Antioxidant; Gastroprotector

Article Outline

1. Introduction

2. Results and discussion

3. Experimental

3.1. General methods

3.1.1. 1-Hydroxy-1-(4-methoxyphenyl)-propane (2)

3.1.2. 1-Hydroxy-1-(4-methoxyphenyl)-propane (2)

3.1.3. 1,2-Dihydroxy-1-(4-methoxyphenyl)-propane (3) and 1-hydroxy-1-(4-methoxyphenyl)-2-m-chlorobenzoyl-propane (4)

3.1.4. 1,2-Dihydroxy-1-(4-methoxyphenyl)-propane (3)

3.1.5. 1-Hydroxy-1-(4-methoxyphenyl)-2-m-chlorobenzoyl-propane (4)

3.2. Antioxidant assay

3.2.1. Free radical scavenging activity (DPPH) method

3.3. Biological assays

3.4. Anti-inflammatory test—vascular increasing permeability induced by acetic acid

3.5. Gastroprotector activity test—ulcerogenesis assay

3.6. Effect on total white blood cell count

3.7. Statistical analysis of data

References