Isolation of Antifungal Valepotriates from Valeriana capense and the Search for Valepotriates in Crude Valerianaceae Extracts

• Published in: Phytochemical analysis Vol. 7; no. 2; pp. 76 - 85
• Main Authors: Fuzzati, N., Wolfender, J. L., Hostettmann, K., Msonthi, J. D., Mavi, S., Molleyres, L. P.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.03.1996
• Subjects: antifungal activity; thermospray liquid chromatography; Valerianaspp; Valerianella locusta
• ISSN: 0958-0344; 1099-1565
• DOI: 10.1002/(SICI)1099-1565(199603)7:2<76::AID-PCA288>3.0.CO;2-L

A lipophilic crude extract of Valeriana capense exhibited antifungal activity against the plant pathogenic fungus Cladosporium cucumerinum. Activity‐guided fractionation of the extract afforded valtrate (1). Isovaltrate (2), didrovaltrate (3), chlorovaltrate (4), valtrate hydrine B4 (5), homovaltrate (6), dihomovaltrate (7), homodidrovaltrate (8), diavaltrate (9) and isovaleroxyhydroxydidrovaltrate (10) were subsequently isolated. The activities of compounds 1, 3 and 6–10 against different fungi were determined. Quantitation of 1 in roots and aerial parts of V. capense has been achieved. Investigation of the valepotriate content in crude extracts of some European Valerianaceae species was performed using thermospray liquid chromatography (TSP LC)‐mass spectrometry (MS) and TSP LC–tandem MS. Lipophilic whole extracts of V. pyrenaica, V. celtica, V. globulariifolia, V. supina and the roots of Valerianella locusta have been analysed using valepotriates 1–10 as reference compounds. Several other valepotriates have been detected in the extracts and their structures tentatively assigned. Chlorovaltrate (4) was found not to be an artefact formed during the extraction procedure when extracts of the roots of Valeriana capense and V. officinalis obtained with chlorinated and non‐chlorinated solvents were investigated by means of TSP LC–MS.