Emma Maldonado

neo-Clerodane diterpenes from Salvia herbacea

Chemical investigation of the aerial parts of Salvia herbacea led to the isolation of eight new neo-clerodane diterpenes (1-8), named tehuanins A-H, and three known compounds. The structures of these compounds were determined by analysis of their spectroscopic data. Three of the new diterpenes possess a 1,8-epoxy group (1-3). This unusual structural feature was confirmed by X-ray diffraction of 1. The structure of the previously isolated 1α,10α-epoxysalviarin was revised. The absolute configuration of 6 was established by X-ray diffraction analysis of its bromo derivative 6a. Cytotoxic and anti-inflammatory activities of these diterpenes were examined. None of the compounds were considered to be cytotoxic; however, compound 7 exhibited anti-inflammatory activity comparable to that of indomethacin.

Methyl dodonates, a new type of diterpenes with a modified clerodane skeleton from Dodonaea viscosa

Abstract Three new modified clerodanes (10, 12, 17) containing a tricyclo[5.4.0.01,3]undecane ring system were isolated from Dodonaea viscosa. These types of compounds have not been found in nature until now, but they have been proposed as hypothetical intermediates in the biogenetic pathway of diterpenes possessing bicyclo[5.4.0]undecane or bicyclo[5.3.0]decane ring systems. In support of this hypothesis, 17 was transformed into the bicyclo[5.4.0]undecane derivative 20. Additionally, we isolated the new 5,10-secoclerodane 21 and several known diterpenes. The structures were elucidated by spectroscopic methods, chemical reactions and X-ray diffraction analysis.

Labdanes and Sucrose Esters from Physalis sordida

Eight new compounds, labdanes 2-4, homoergostane 10, and sucrose esters 12-15, were isolated from aerial parts of Physalis sordida together with several known compounds. Structures of the new compounds were elucidated using spectroscopic evidence and chemical transformations. The structure of 10 was confirmed by X-ray crystallographic analysis of its methyl ester. Anti-inflammatory activity of compounds 1, 2, 4, 5, and 12-15 was evaluated using the TPA-induced mouse ear edema test. Compounds 12 (IC(50) 0.26 mumol/ear) and 15 (IC(50) 0.24 mumol/ear) showed anti-inflammatory activity similar to that of indomethacin (IC(50) 0.24 mumol/ear).

Salviandulines A and B. Two secoclerodane diterpenoids from Salvia lavanduloides

Abstract Two novel 9,10-secoclerodane diterpenoids, salviandulines A and B, were isolated from aerial parts of Salvia lavanduloides . Their structures were established by high resolution NMR and X-ray diffraction analysis.

Eudesmane derivatives from Epaltes mexicana

Abstract Investigation of Epaltes mexicana afforded several eudesmane derivatives, all of them closely related to cuauhtemone. The structures of two new compounds were elucidated by spectroscopic, methods.

A One Step Transformation of 4a,5b-Epoxygermacranolide into Pseudoguaianolide

Transformation par adsorption sur terre bentonitique du 4α,5α-epoxyinunolide en inuviscolide, 4α,5α-epoxy-10α-14H-inuviscolide et 8-epiconfertine

Philadelphicalactones C and D and other cytotoxic compounds from Physalis philadelphica

Two new withanolides, philadelphicalactone C (1) and philadelphicalactone D (4), along with the known withaphysacarpin (3), ixocarpanolide (5), philadelphicalactone A (6), and ixocarpalactone A (7) were isolated from the aerial parts of Physalis philadelphica Lam. Structures of these compounds were determined by spectroscopic analyses and that of philadelphicalactone C (1) was confirmed by X-ray crystallographic analysis. Evaluation of the cytotoxic activity of all isolates and the derivative 2 against a panel of human cancer cell lines indicated a potent activity of compounds 2, 3, 6, and 7.

Diterpenes from Salvia breviflora

Abstract In addition to compounds which are ubiquitous in Salvia species, like ursolic and oleanolic acids, we have isolated two heterobicyclic diterpenes, brevifloralactone and brevifloralactone acetate.

Polystachynes A-E, five cis-neo-clerodane diterpenoids from Salvia polystachya

From the aerial parts of Salvia polystachya five new neo-clerodane diterpenoids, polystachynes A-E, have been isolated. The structures were established by spectroscopic methods, including the X-ray analysis of polystachynes C and D. The known clerodanes salvifaricin, linearolactone and dehydrokerlin were also isolated.

Amarisolide, a neo-clerodane diterpene glycoside from Salvia amarissima☆

A new neo-clerodane glycoside, amarisolide, has been isolated from the aerial parts of Salvia amarissima. Its structure was established as 2β-O-β-D-glucopyranosyl neo-cleroda-3,13(16),14-trien-15,16-epoxy-18,19-olide by chemical and spectroscopic means.