Description
Ethyl orsellinate is a lichen metabolite and a derivative of lecanoric acid (Item No. 22710) that has antiproliferative activities.1,2 It inhibits the proliferation of human Hep-2 larynx carcinoma, MCF-7 breast cancer, and 786-0 kidney carcinoma cells, as well as B16-F10 murine melanoma and non-cancerous Vero cells (IC50s = 31.2, 70.3, 47.5, 64.8, and 28.1 µg/ml, respectively).2 Ethyl orsellinate is toxic to brine shrimp (A. salina) with an LC50 value of 495 µM.3WARNING This product is not for human or veterinary use.
Definition
ChEBI: 2,4-dihydroxy-6-methylbenzoic acid ethyl ester is a 4-hydroxybenzoate ester.
General Description
Ethyl 2,4-dihydroxy-6-methylbenzoate is also referred as ethyl orsellinate. It was isolated from chloroform extract of Peltigera aphthosa. It is one of the product formed during alcoholyses of lecanoric acid.
Synthesis
The stem bark of Illicium difengpi (5.0?kg) was powdered and extracted three times with aqueous ethanol (ethanol/water 8:2) under reflux. The solvent was then evaporated under reduced pressure to obtain a dry residue (150?g). The residue was suspended in water (2?L) and extracted successively with petroleum ether (3 × 2?L), EtOAc (3 × 2?L) and BuOH (3 × 2?L), affording 5?g, 70?g, and 40?g, respectively, of each dried fraction. The EtOAc fraction was subjected to silica gel column chromatography using gradient elution (CH2Cl2/CH3OH, 200:1 to 2:1, v/v) to give four main fractions, of which was purified by successive silica gel column chromatography (CH2Cl2/CH3OH, 100:1→20:1); 2,4-dihy-droxy-6-methyl-benzoic acid ethyl ester (Ethyl 2,4-dihydroxy-6-methylbenzoate) was obtained from the fraction eluted by CH2Cl2/CH3OH (40:1)[1].
Structure and conformation
The mol-ecular structure of Ethyl 2,4-dihydroxy-6-methylbenzoate contains a methyl group, two hydroxyl groups, and a carboeth-oxy group, which are attached to C2, C4, C6 and C7 of the central benzene ring, respectively. An intra-molecular O3—H3···O1 hydrogen bond stabilizes the mol-ecular conformation. In the crystal, O4—H4···O3i and C3—H3A···O4ii hydrogen bonds link the mol-ecules into double strands parallel to the direction. In the solid state, the compound also forms offset slanted stacks of alternating inversion-related mol-ecules along the a-axis direction[1].
References
[1] Xiong, Huiping , et al. "Crystal structure of the ethyl 2,4-dihydroxy-6-methylbenzoate from Illicium difengpi K.I.B et K.I.M. " IUCrData 12(2018).
