In vitro growth inhibition and bactericidal activity of spathulenol against drug-resistant clinical isolates of Mycobacterium tuberculosis

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.

UHPLC high resolution orbitrap metabolomic fingerprinting of the unique species Ophryosporus triangularis Meyen from the Atacama Desert, Northern Chile

ABSTRACT High-resolution mass spectrometry is currently used to determine the mass of biologically active compounds in plants and UHPLC-Orbitrap is a relatively new technology that allows fast fingerprinting and metabolomics analysis. In this work, several phenolic compounds including eleven phenolic acids, two fatty acids, two chromones and fourteen flavones were rapidly identified in the methanolic extracts of aerial parts and flowers of the unique Chilean species Ophryosporus triangularis Meyen, Asteraceae, growing in the Atacama Desert by means of ultrahigh resolution liquid chromatography orbitrap MS analysis (UHPLC-PDA-OT-MS) for the first time. The UHPLC-MS fingerprint generated can be used for the authentication of this endemic species. The methanolic extracts of the aerial parts and flowers showed also antioxidant capacities (65.34 ± 1.32 and 52.41 ± 1.87 µg/ml in the DPPH assay, 184.88 ± 13.22 and 196.80 ± 13.28 µmol TE/g dry weight in the ferric reducing power assay and 56.17 ± 3.03 and 65.41 ± 1.96% in the superoxide anion scavenging assay, respectively).

Diterpenoids from Azorella compacta (Umbelliferae) active on Trypanosoma cruzi

The anti-Trypanosoma cruzi activity of natural products isolated from Azorella compacta was evaluated, with particular emphasis on their effect against intracellular amastigotes. Five diterpenoids from A. compacta derived from mulinane and azorellane were isolated and identified. Only two products, named azorellanol (Y-2) and mulin-11,3-dien-20-oic acid (Y-5), showed trypanocidal activity against all stages of T. cruzi including intracellular amastigotes. At 10 æM, these compounds displayed a strong lytic activity. It ranged from 88.4 ± 0.6 to 99.0 ± 1 percent for all strains and stages evaluate, with an IC50 /18 h values of 20-84 æM and 41-87 æM, respectively. The development of intracellular amastigotes was also inhibited by nearly 60 percent at 25 æM. The trypanocidal molecules Y-2 and Y-5 did show different degrees of cytotoxicity depending on the cell line tested, with an IC50 /24 h ranging from 33.2 to 161.2 æM. We evaluated the effect of diterpenoids against intracellular T. cruzi forms by immunofluorescent identification of a specific membrane molecular marker (Ssp-4 antigen) of the T. cruzi amastigote forms. The accuracy and reproducibility of the measurements were found to be outstanding when examined by confocal microscopy

Actividad de diterpenoides de azorella compacta, llareta, sobre amastigotes de trypanosoma cruzi / Activity of dipernoids isolated from azorella compacta, llareta, on trypanosoma cruzi amastigotes

The trypanocidad activity against amastigote forms of SPA-14, Tulahuen and G strains and CL Brener clone of Trypanosoma cruzi of diterpenoids isolated from Azorella compacta. Phil. (Llareta), a plant with ethnomedicinal prestige from prespanish age, was investigated. Amastigocidal activity was shown in azorellanol (2), diterpene isolated by first time, with an inhitory concentration 50 (IC) that varied between 60 M (CL Brener clone) and 84 M (SPA-14 strain), and in mulin -11,13 -dien-20-oico acid (5) with IC between 41 µM (G strain) and 87 mM (CL Brener clone). The cytotoxicity levels of both compounds against Hela and Vero cells and macrophages J144 are lower than nifurtimox and similar to gentian violet