Acetophenone glycosides from thyme (Thymus vulgaris L.)

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Pharmacology

Background:

• Thyme (Thymus vulgaris) is a well-known medicinal herb with a rich history of traditional use.
• Extracts of thyme have been investigated for various bioactive compounds, including flavonoids and essential oils.
• Acetophenone glycosides are a class of compounds found in various plants, known for potential biological activities.

Purpose of the Study:

• To isolate and characterize acetophenone glycosides from thyme extracts.
• To identify novel compounds within the butanol-soluble fraction of thyme.
• To evaluate the cytotoxic potential of the isolated compounds against human leukemia cells.

Main Methods:

• Solvent extraction of thyme followed by fractionation (butanol-soluble fraction).
• Isolation of compounds using chromatographic techniques.
• Structure elucidation using spectroscopic methods, including Mass Spectrometry (MS), Nuclear Magnetic Resonance (NMR), and 2D-NMR.
• Cytotoxicity assay to assess inhibition of DNA synthesis in human leukemia cells.

Main Results:

• Four acetophenone glycosides were successfully isolated from the thyme extract.
• Two new compounds were identified and their structures elucidated: 4-hydroxyacetophenone 4-O-[5-O-(3, 5-dimethoxy-4-hydroxybenzoyl)-beta-D-apiofuranosyl]-(1-->2)-beta-D-glucopyranoside (1) and 4-hydroxyacetophenone 4-O-[5-O-(4-hydroxybenzoyl)-beta-D-apiofuranosyl]-(1-->2)-beta-D-glucopyranoside (2).
• Compound 1 demonstrated weak cytotoxicity, specifically inhibiting DNA synthesis in human leukemia cells.

Conclusions:

• The study successfully identified and characterized acetophenone glycosides from thyme, including two previously unknown compounds.
• Compound 1, a novel acetophenone glycoside, exhibits preliminary cytotoxic activity against human leukemia cells.
• These findings contribute to the understanding of thyme's chemical constituents and their potential therapeutic applications in cancer research.