ABSTRACT Spathulenol was isolated from an extract of Azorella compacta Phil., Apiaceae, by various chromatographic method; identification of the chemical structure was confirmed by comparing its spectroscopic data with those reported in the literature. The anti-Mycobacterium tuberculosis activity of spathulenol was evaluated on MDR, pre-XDR, and XDR clinical isolates of M. tuberculosis, as well as on the reference susceptible strain H37Rv and its cytotoxic activity was evaluated on the Vero Cell Line. The anti-M. tuberculosis activity of spathulenol was twice as potent against the MDR, pre-XDR, and XDR clinical isolates (6.25 µg/ml) than on the susceptible H37Rv strain (12.5 µg/ml). Additionally, the anti-M. tuberculosis activity shown by spathulenol was established as bactericidal on drug-resistant and susceptible strains of M. tuberculosis. Finally, cytotoxic activity on the Vero cell line (CC50 = 95.7 µg/ml) indicated that spathulenol is a selective anti-M. tuberculosis compound, with a selective index of 15.31 against drug-resistant clinical isolates of M. tuberculosis.

The cytotoxicity, scavenging and lipid peroxidation - inhibiting activities of 5,3 ',4'- trihydroxy - 7 - methoxyflavanone, isolated from Haplopappus rigidus Phil.(Asteraceae), were evaluated in a series of in vitro assays involving free radicals (ABTS, DPPH), ascorbate - induced rat liver microsomal lipid peroxidation, and the cytotoxicities to three human tumor cell lines . 5,3',4'-trihydroxy - 7 - methoxyflavanone , at concentration of 0.3 mg/mL , elicited an 97.4 % scavenging effect on DPPH; TEAC 1.35mM on ABTS , preventing microsomal lipid peroxidation IC50 1.8 μM and ED50 3.23 - 5.66 ug/mL against three human tumor cell, indicating that the flavanone 5,3',4'-trihydroxy - 7 - methoxyflavanone was effectively cytotoxic , as well as free radicals scavenger and a good inhibitor of iron/ascorbate induced lipid peroxidation in a dose dependent manner.

The inhibition of the enzyme acetylcholinesterase is considered as a strategy for the treatment of Alzheimer's disease, senile dementia, ataxia, and myasthenia gravis. Three lanostane- and two cycloartane-type triterpenes, together with two mulinane-type diterpenes were isolated from petroleum ether extract of the whole shrub of Azorella trifurcata (Gaertn.) Pers. Their effect on the enzyme acetylcholinesterase was assessed as well. In addition, this is the first report of these triterpenes in the genus Azorella.

The antioxidant properties oí Acantholippia deserticola, a herb used in traditional northern Chilean medicine was studied using free radical - generating systems. The 50% aqueous - ethanol extract oí Acantholippia deserticola protected against non-enzymatic lipid peroxidation in microsomal membranes of rat, induced by an Fe++ - ascorbate system and measured spectrophotometrically by the TBARS test, and had strong free radical scavenging capacities on stable ABTS and DPPH radicáis. The results shows that the IC50 valué of the 50% aqueous - ethanolic extract oí A.deserticola is 18 ± 0.5 μg/mL in DPPH radical - scavenging, 15 ± 0.8 μg/mL in lipid peroxidation , Total Antioxidant Activity (TAA) is 0.95 mM of Trolox per mg/mL of extract. The total phenolics content of extract is 725 ± 12 mg of gallic acid equivalent per g of dried extract. The results indicate that the 50% aqueous - ethanol extract oí Acantholippia deserticola clearly has antioxidant properties.

Constituents of Helenium atacamense Cabr were investigated following a preliminary screening of the biotoxicity against Artemia salina and the antitumoral activity of ethanol extract . Three compounds already identified were isolated from aerial parts of Helenium atacamense Cabr, and their structures were elucidated as helenalin, quercetin and 3-O-methylquercetin based on mass and various nuclear magnetic resonance techniques . Quercetin and 3- O- methylquercetin were tested by using TEAC Test

Antibacterial activity and biotoxicity against Artemia salina of chloroform and alcohol extracts and isolated products from four plants used in ethnomedicine in northern Chile is reported. Nine compounds already identified were isolated from aerial parts of Artemisia copa Phil., Acantholippia punensis Botta, Ephedra andina Poepp. ex C. A . Mey and Haplopappus rigidus Phil : 3,5 dihydroxy 6, 7, 3', 4' tetramethoxyflavone, lupeol, beta amyrine , beta sitosterol, ephedrine, 2 ethylhexanol phthalate , 18 acetoxy cis cleroda 3,13 Z dien 15 oic acid, 5,4' dihydroxy 7 methoxyflavanone and 3,5,7 trihydroxy 6, 4' dimethoxyflavone

In addition to azorellanol a new diterpenoid 7-deacetylazorellanol, has been isolated from the aerial parts of Laretia acaulis (Cav.) Gill et Hook (Umbelliferae). Its structure was based on spectroscopic comparison with azorellanol and chemical grounds. Azorellanol and 7-deacetylazorellanol showed marked inhibitor activity against trophozoites of protozoan parasite Toxoplasma gondii. The 50 % inhibitory dose for azorellanol was calculated in 54 muM and for 7-deacetylazorellanol was 42 mM.

Desde de las partes aéreas de Laretia acaulis (Cav.) Gill et Hook hemos aislado azorellanol y un nuevo diterpenoide 7-desacetilazorellanol. Su estructura esta basada en la comparación de sus datos espectroscópicos con los de azorellanol y transformaciones químicas. Azorellanol y 7-desacetilzorellanol muestran una marcada actividad inhibitoria frente a los trofozoitos del protozoo parásito Toxoplasma gondii. La dosis inhibitoria 50 (DI50) de azorellanol es 54 myM y para 7-desacetylazorellanol 42 myM

The fractionation work of the aerial parts of Senecio atacamensis Phil. afforded, in addition to the already known 6beta -hydroxyeremophilenolide, a new sesquiterpene lactone 6beta - hydroxy - 8alpha - methoxyeremophil -1(10),7(11) - dien - 8beta,12 olide. The structures were established by spectral data, in particular 2D NMR (DEPT, DQF-COSY, HMQC, HMBC and ROESY).

Desde las partes aéreas de Senecio atacamensis Phil. se ha aislado una nueva lactona sesquiterpénica : 6beta - hidroxi - 8alfa - metoxieremofil - 1(10),7(11) - dien - 8beta,12 - olida, junto a la ya conocida 6beta - hidroxieremofilanólida, Las estructuras fueron establecidas usando la información espectral , en particular, las técnicas de RMN en 2D (DEPT, DQF-COSY, HMQC, HMBC and ROESY).

A new glycoditerpenoid , 13 - O - beta - xylopiranosylmanool 1, named rigiduside was isolated from Haplopappus rigidus Phil. , together with the flavonoid 3,5,7- trihydroxy - 6,4’ - dimetoxyflavone, compound that showed a moderate leishmanicidal effect against two species of Leishmania. The structures were established by spectral data

De Haplopappus rigidus .Phil , (Asteraceae) se ha aislado un nuevo glicoditerpenoide al que se ha llamado rigidusido y ha sido caracterizado como 13 - O - beta - xilopiranosilmanool ( 1 ). Además, se ha identificado el flavonoide :3, 5, 7 -trihidroxi - 6,4’ - dimetoxiflavona , de moderada actividad leishmanicida. Las estructuras químicas han sido establecidas por las propiedades espectroscópicas .