ABSTRACT
In this paper, the isolation of one new iridoid glucoside, 6ß-acetoxyipolamiide (1: ), and thirteen (2: â-â14: ) known congeners from two Lamiaceae species, Stachys ocymastrum and Premna resinosa, leaf extracts is reported. The structural determination of the isolated compounds was performed by mono- and bidimensional NMR spectroscopic analysis as well as MS experiments. The isolates were assayed for their antiangiogenic activity by two in vivo models, zebrafish embryos and chick chorioallantoic membrane assays. The compounds with a significant antiangiogenic activity in both assays were ß-hydroxyipolamiide (2: ), ipolamiide (3: ), and buddlejoside A5 (8: ). 6-O-α-l-(3â³-O-p-Methoxycinnamoyl-4â³-O-acetyl)rhamnopyranosyl catalpol (13: ) and 6-O-α-l-(2â³-trans-caffeoyl)rhamnopyranosyl catalpol (6: ) showed the best antiangiogenic response on blood vessel growth in zebrafish embryos, whereas saccatoside (10: ) and 6-O-α-l-(2â³-O - : p-methoxycinnamoyl-3â³-O-acetyl)rhamnopyranosyl catalpol (14: ) resulted in a strong reduction of capillary formation in the chorioallantoic membrane assay.
Subject(s)
Angiogenesis Inhibitors/pharmacology , Iridoids/isolation & purification , Lamiaceae/chemistry , Stachys/chemistry , Animals , Biological Assay , Chick Embryo , Dose-Response Relationship, Drug , Iridoids/pharmacology , Magnetic Resonance Spectroscopy , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Leaves/chemistry , ZebrafishABSTRACT
ABSTRACT The phytochemical study of Galium tunetanum Lam., Rubiaceae, leaves led to the isolation of 13 compounds from the chloroform-methanol and the methanol extracts, including six iridoid glycosides, one non-glycoside iridoid, two p-coumaroyl iridoid glycosides, two phenolic acids, and two flavonoid glycosides. The structural determination of the isolated compounds was performed by mono- and bidimensional NMR spectroscopic data, as well as ESI-MS experiments. All compounds were isolated from this species for the first time. The anti-angiogenic effects of the isolated iridoids were also reported on new blood vessels formation using the chick embryo chorioallantoic membrane as in vivo model. Results showed that among the isolated iridoids tested at the dose of 2 µg/egg, asperuloside (1), geniposidic acid (2), and iridoid V1 (3) reduced microvessel formation of the chorioallantoic membrane on morphological observations using a stereomicroscope. The anti-angiogenic effects of the active compounds, expressed as percentages of inhibition versus control, were 67% (1), 59% (2), and 54% (3), respectively. In addition, the active compounds were able to inhibit angiogenesis in the chorioallantoic membrane assay, in a dose-dependent manner (0.5-2 µg/egg) as compared to the standard retinoic acid.
ABSTRACT
A phytochemical study of n-hexane, CHCl3, and CHCl3-MeOH extracts of Aphanamixis polystachya leaves led to the isolation of 10 compounds. Five of them turned out to be new natural compounds, including two mexicanolide-type (1, 2: ) and three polyoxyphragmalin-type (3: -5: ) limonoids, together with two known andirobin-type limonoids (6, 7: ) and three phenolic derivatives. The structures of the new compounds were established on the basis of spectroscopic methods to be 8-hydro-14,15-en-cabralin (1: ), 3-deacetyl-8-hydro-cabralin-14,15-en-3-one (2: ), 20,22-dihydroxy-21,23-dimethoxytetrahydrofuran khayanolide A (3: ), 1-deacetyl-3-dehydroxy-3-oxokhaysenelide E (4: ), and meliaphanamixin A (5: ). All compounds were isolated for the first time from this species. The ability of the isolated limonoids to interact with the molecular chaperone Hsp90 was tested. Compounds 6: and 7: were the most active.
