Kaempferol glycosides from Lobularia maritima and their potential role in plant interactions.
Six kaempferol glycosides, four of them characterized for the first time, were isolated from the leaf extract of Lobularia maritima. The structural elucidation was performed by a combined approach using Electrospray-Ionization Triple-Quadrupole Mass-Spectrometric (ESI/TQ/MS) techniques, and 1D- and 2D-NMR experiments (1H, 13C, DEPT, DQ-COSY, TOCSY, ROESY, NOESY, HSQC, HMBC, and HSQC-TOCSY). The isolated kaempferol derivatives have different disaccharide substituents at C(3) and four of them have a rhamnose unit at C(7). To evaluate their potential allelopathic role within the herbaceous plant community, the compounds, as well as the aglycone obtained from enzymatic hydrolysis, have been tested in vitro on three coexisting plant species, Dactylis hispanica, Petrorhagia velutina, and Phleum subulatum. The results obtained allow us to hypothesize that the type of the sugar modulates the biological response. The bioassay data, analyzed by a multivariate approach, and grouping the compounds on the basis of the number of sugar units and the nature of carbohydrates present in the disaccharide moiety, indicate a structure-activity relationship.
Fiorentino
Antonio
A
Dipartimento di Scienze della Vita, Laboratorio di Fitochimica, Seconda Università degli Studi di Napoli, via Vivaldi 43, I-81100 Caserta. antonio.fiorentino@unina2.it
Ricci
Andreina
A
D'Abrosca
Brigida
B
Golino
Annunziata
A
Izzo
Angelina
A
Pascarella
Maria Teresa
MT
Piccolella
Simona
S
Esposito
Assunta
A
D019607:Brassicaceae / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry* / Q000494:pharmacology; D044949:Kaempferols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D010944:Plants / Q000187:drug effects; D013329:Structure-Activity Relationship
D006027:Glycosides; D044949:Kaempferols; D010936:Plant Extracts; C006552:kaempferol