Bibiana Zapata

Citral and carvone chemotypes from the essential oils of Colombian Lippia alba (Mill.) N.E. Brown: composition, cytotoxicity and antifungal activity.

Two essential oils of Lippia alba (Mill.) N.E. Brown (Verbenacea), the carvone and citral chemotypes and 15 of their compounds were evaluated to determine cytotoxicity and antifungal activity. Cytotoxicity assays for both the citral and carvone chemotypes were carried out with tetrazolium-dye, which showed a dose-dependent cytotoxic effect against HeLa cells. Interestingly, this effect on the evaluated cells (HeLa and the non-tumoural cell line, Vero) was lower than that of commercial citral alone. Commercial citral showed the highest cytotoxic activity on HeLa cells. The antifungal activity was evaluated against Candida parapsilosis, Candida krusei, Aspergillus flavus and Aspergillus fumigatus strains following the standard protocols, Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing and CLSI M38-A. Results demonstrated that the most active essential oil was the citral chemotype, with geometric means-minimal inhibitory concentration (GM-MIC) values of 78.7 and 270.8 microg/mL for A. fumigatus and C. krusei, respectively. Commercial citral showed an antifungal activity similar to that of the citral chemotype (GM-MIC values of 62.5 microg/mL for A. fumigatus and 39.7 microg/mL for C. krusei). Although the citronellal and geraniol were found in lower concentrations in the citral chemotype, they had significant antifungal activity, with GM-MIC values of 49.6 microg/mL for C. krusei and 176.8 microg/mL for A. fumigatus.

Synthesis and biological evaluation of dehydroabietic acid derivatives

A series of C18-oxygenated derivatives of dehydroabietic acid were synthesized from commercial abietic acid and evaluated for their cytotoxic, antimycotic, and antiviral activities.

In vitro activity of fluconazole, itraconazole, voriconazole and terbinafine against fungi causing onychomycosis

Background.  Onychomycosis is one of the commonest dermatological diseases worldwide. The antifungal activity of current medications varies, and treatment failure occurs in 25–40% of treated patients.

Synthesis and biological evaluation of (+)-labdadienedial, derivatives and precursors from (+)-sclareolide

Labdadienedial and a series of C15,C16-functionalized derivatives were synthesized from commercial (+)-sclareolide and evaluated for their cytotoxic, antimycotic, and antiviral activities. Their precursors were similarly evaluated.

Cytotoxic, immunomodulatory, antimycotic, and antiviral activities of semisynthetic 14-hydroxyabietane derivatives and triptoquinone C-4 epimers

A series of C14-hydroxy derivatives of dehydroabietic acid were synthesised from commercial abietic acid and evaluated for their cytotoxic, antimycotic, and antiviral activities. From these C14-hydroxy derivatives, triptoquinone C-4 epimers were obtained and their immunomodulatory activity was additionally evaluated. None of the tested compounds showed antiviral activity against herpes simplex virus type 1 (HHV-1), and nor did they display antimycotic activity against certain Aspergillus, spp. except for one compound, abieta-8,11,13-trien-14,18-diol. Interestingly, two triptoquinone epimers showed cytotoxic activity, and one of them induced mitochondrial potential loss, DNA damage and cell cycle distribution alterations in Jurkat cells, but not in human peripheral blood mononuclear cells. In addition, these compounds inhibited monocytes differentiation and production of pro-inflammatory cytokines, IL-1β and TNF-α, and the anti-inflammatory cytokine IL-10 in the presence of LPS. In conclusion, one of the triptoquinone molecules could be a promising scaffold for the development of novel anti-cancer agents, and two of them could be potential anti-inflammatory agents.

Cytotoxic activity of Asteraceae and Verbenaceae family essential oils

Thirty-six essential oils from Verbenaceae and Asteraceae family plants along with their major constituents were evaluated to determine cytotoxicity on Jurkat, HeLa, HepG2 and Vero cell lines. The plants were collected in different regions of Colombia, and their essential oils were extracted through microwave-assisted hydrodistillation and then characterized through GC/MS and GC/FID analyses. Cytotoxic activity testing was carried out using a tetrazolium-dye (MTT) assay. The essential oils from Lippia alba Citral and Carvone chemotypes showed the lowest IC50 and selectivity index (IS) > 10. The essential oils from Asteraceae family were not selective against the tumor cell lines tested. Citral chemotype L. alba essential oils showed values up to 27.2, and Carvone chemotype L. alba essential oils showed values up to 30.7. Citral, showed the highest cytotoxic activity, with an SI value of 1241, and Limonene and Linalool showed SI values of 6.97 and 10.1, respectively, on HeLa cells.

First Synthesis of Lissoclimide-Type Alkaloids

The first synthesis of lissoclimide-type alkaloids is described. Starting from commercial (+)-sclareolide, the aldehyde -bicyclohomofarnesal is synthesized and coupled, through an aldol reaction, with succinimide. The antitumor activity of several lissoclimide analogues is also reported.

ACTIVIDAD IN VITRO ANTI-CANDIDA Y ANTI-ASPERGILLUS DE ACEITES ESENCIALES DE PLANTAS DE LA FAMILIA PIPERACEAE

Plants of the Piperaceae family have been used with medicinal purposes in different regions around the world. In vitro antifungal activity of 10 essential oils from species of Piper genus were measured by determination of minimum inhibitory concentration (MIC) against A. flavus fungi ATCC 204304 and A. fumigatus ATCC 204305 following the standard protocol CLSI M38-A. In addition, Candida krusei ATCC 6258 and C. parapsilosis ATCC 22019 were evaluated with modified protocol M27-A2. The essential oil with the most antifungal activity was Piper sanctifelisis for C. krusei (CMI: 125 µg/mL).