Nine new limonoids ( 1 – 9 ) were isolated from the stem bark of Guarea guidonia ( 1 – 4 ) and Cedrela odorata ( 5 – 9 ). Their structures were elucidated using 1D and 2D NMR and MS data and chemical methods as three A2,B,D- seco -type limonoids ( 1 – 3 ), a mexicanolide ( 4 ), three nomilin-type ( 5 – 7 ) limonoids, and two limonol derivatives ( 8 and 9 ). A DFT/NMR procedure was used to define the relative configurations of 1 and 3 . A surface plasmon resonance approach was used to screen the Hsp90 binding capability of the limonoids, and the A2,B,D- seco -type limonoid 8-hydro-(8 S* ,9 S *)-dihydroxy-14,15-en-chisomicine A, named chisomicine D ( 1 ), demonstrated the highest affinity. By means of mass spectrometry data, biochemical and cellular assays, and molecular docking, 1 was found as a type of client-selective Hsp90 inhibitor binding to the C-terminus domain of the chaperone.

A phytochemical study of -hexane, CHCl, and CHCl-MeOH extracts of 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.

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In this paper, the isolation of one new iridoid glucoside, 6β-acetoxyipolamiide (1), and thirteen (2 – 14) 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 β-hydroxyipolamiide (2), ipolamiide (3), and buddlejoside A5 (8). 6-O-α-l-(3″-O-p-Methoxycinnamoyl-4″-O-acetyl)rhamnopyranosyl catalpol (13) and 6-O-α-l-(2″-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-(2″-O - p-methoxycinnamoyl-3″-O-acetyl)rhamnopyranosyl catalpol (14) resulted in a strong reduction of capillary formation in the chorioallantoic membrane assay.

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