Supervisors info:
Σκαλτσά Ελένη, Καθηγήτρια, Τμήμα Φαρμακευτικής, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Summary:
S. candida Bory & Chaubard is a perennial shrub with tomentose stem, growing wild in Greece in mountainous and rocky places. Dioskorides (40-90 AD) was the first who mentioned this genus. Several centuries later, references to the genus were found in the work of Nicholaos Myrepsos’ Dynameron (late 13th century). Several Stachys species are used in folk medecine. S. candida was collected at Mt Taygetus (Peloponnese). Its aerial parts were extracted with dichloromethane and methanol, successively. The methanol extract has been subjected to further chromatographic separations and yielded 11 secondary metabolites: nine flavonoids, i.e. calycopterin, apigenin-7-O-β-D-glucoside, chrysoeriol, chrysoeriol-7-O-β-D-glucoside, chrysoeriol-7-O-β-D-(3΄΄-E-p-coumaroyl)- glucopyranoside, isoscutellarein-7-O-[6΄΄΄-O-acetyl-β-D-allopyranosyl)-( 12)]-β-D-glucopyranoside, isoscutellarein-7-O-[6΄΄΄-O-acetyl-β-D-allopyranosyl)-( 12)-6΄΄-Ο-acetyl]-β-D-glucopyranoside, 4΄- methyl-isoscutellarein-7-O-[6΄΄΄-O-acetyl-β-D-allopyranosyl)-( 12)]-β-D-glucopyranoside, 4΄-Ο-methyl-hypolaetin-7-O-[6΄΄΄-O-acetyl-β-D-allopyranosyl)-( 12)]-β-D-glucopyranoside, one phenylethanoid glucoside, acteoside and one phenolic acid, chlorogenic acid. Moreover, part of the methanol extracts of S. candida Bory & Chaubard, and Stachys iva Griseb. and two fractions obtained from the methanol extract of S. candida were tested for potential antibacterial activity against two phytopathogenic bacteria, Pseudomonas savastatoi pv. savastatoi and Clavibacter michiganensis subsp. michiganensis. The present study is the second phytochemical study of S. candida Bory & Chaubard. Calycopterin, chrysoeriol and chrysoeriol-7-O-β-D-(3΄΄-E-p-coumaroyl)- glucopyranoside have been previously isolated from this species. Isoscutellarein-7-O-[6΄΄΄-O-acetyl-β-D-allopyranosyl)-(12)]-β-D-glucopyranoside was the main compound of the plant. Finally, the biological assays revealed that S. candida Bory & Chaubard has the greatest inhibitory effect on the growth of Clavibacter michiganensis subsp. michiganensis with an average rate of 48.6%.
Keywords:
S. candida Bory & Chaubard, flavonoids, chlorogenic acid, acteoside, biological assays
