6,7-Dehydroroyleanone, a Diterpenoid Quinone fromSalvia moorcraftiana

Abstract

6,7-Dehydroroyleanone (12-hydroxyabieta-6,8,12-trien-1 1, 14-dione) (1) has been isolated for the first time from the roots of Salvia moorcraftiana wall. (Labiatae) and identified on the basis of its spectroscopic and chemical analysis.

7-O-Methylhorminone and Other Cytotoxic Diterpene Quinones from Lepechinia bullata

“…The third compound 3, isolated as yellow needles, mp 126-128°, showed many spectroscopic properties similar to those of horminone [2], justifying a royleanone-type structure.…”

“…The bioactive MeOH extract was then separated by solvent extraction and bioassaydirected chromatography to afford three cytotoxic diterpene quiñones, namely, 6,7-dehydroroyleanone [! }, horminone [2], and 7-O-methylhorminone [31-The last compound is a new natural product, whose presence in a plant sample directly extracted with CHC13 was confirmed by tic.…”

“…6,7-Dehydroroyleanone [1] has been isolated from plants of the Labiatae family, including Plectranthus (1,3), Rosmarinus (4), Coleus (5), Salvia (2,6,7), as well as Inula (Compositae) (8) and Podocarpus (Podocarpaceae) (9). Horminone [2] was obtained previously from Rosmarinus (4), Hormium( 10), Plectranthus (1), Coleus{ 5), and Salvia (4,6,(11)(12)(13) species. Both compounds are reported here for the first time from L. bullata, which has not been previously investigated.…”

“…Protons of compound 2 were then assigned by comparison with those of 3• With the proton assignments available, the protonated carbons could be assigned from the HETCOR spectrum. In order to aid the assignments of quaternary carbons, selective INEPT experiments (24) were performed with horminone [2], In the /-modulated selective INEPT experiment, a particular proton is irradiated with a soft pulse resulting in magnetization transfer and a selective enhancement of carbon atoms three bonds away from the irradiated proton. Thus, polarization transfer from H-7 (3/ = 6 Hz) enhanced a carbonyl resonance (189.0 ppm), an aromatic carbon resonance (147.8 ppm), and a protonated resonance (45.7 ppm, C-5), of which the former two could be assigned to C-14 and C-9, respectively.…”

Bioactive Diterpenoids Isolated from Salvia mellifera

“…The antibacterial activities of extracts from some Saluia have previously been reported (Ikram and Haq, 1980;Ross et al, 1980). Various abietatriene diterpenes have been isolated from Saluia species (Bakshi et al, 1984) but little is known about the relationship between these metabolites and the antibacterial activity of the extracts.…”