Colombian flora includes plant families such as Labiatae and Verbenaceae which are employed for treatment of several diseases. In this study, the chemical compositions of essential oils belonging to Labiatae and Verbenaceae families were determined by GC-MS and GC-FID, respectively. The antiviral activity of forty essential oils of these plants and some monoterpenes were evaluated on Human Herpes Viruses types 1 and 2 using end-point titration technique (EPTT). Furthermore, the essential oils and monoterpenes with higher activity reported in the screening were used to evaluate the inhibitory effect on pre-infective stages. The essential oils with the most anti-herpetic activity were those of Labiatae family with Rf values of 1 × 10² and 1 × 10³ against one Tissue Culture Infectious Dose 50 (TCID₅₀) of HHV-1 and HHV-2. Moreover Lepechinia salvifolia, Hyptis mutabilis, Lepechinia vulcanicola, Mintostachys mollis and Ocimum campechianum essential oils showed inhibitory activity in the early stages of infection.

Quinones are secondary metabolites of higher plants associated with many biological activities, including antiviral effects and cytotoxicity. In this study, the anti-herpetic and anti-dengue evaluation of 27 terpenyl-1,4-naphthoquinone (NQ), 1,4-anthraquinone (AQ) and heterocycle-fused quinone (HetQ) derivatives was done in vitro against Human Herpesvirus (HHV) type 1 and 2, and Dengue virus serotype 2 (DENV-2). The cytotoxicity on HeLa and Jurkat tumor cell lines was also tested. Using plaque forming unit assays, cell viability assays and molecular docking, we found that NQ 4 was the best antiviral compound, while AQ 11 was the most active and selective molecule on the tested tumor cells. NQ 4 showed a fair antiviral activity against Herpesviruses (EC₅₀: <0.4 µg/mL, <1.28 µM) and DENV-2 (1.6 µg/mL, 5.1 µM) on pre-infective stages. Additionally, NQ 4 disrupted the viral attachment of HHV-1 to Vero cells (EC₅₀: 0.12 µg/mL, 0.38 µM) with a very high selectivity index (SI = 1728). The in silico analysis predicted that this quinone could bind to the prefusion form of the E glycoprotein of DENV-2. These findings demonstrate that NQ 4 is a potent and highly selective antiviral compound, while suggesting its ability to prevent Herpes and Dengue infections. Additionally, AQ 11 can be considered of interest as a leader for the design of new anticancer agents.

The recent COVID-19 crisis has highlighted the importance of RNA-based viruses. The most prominent members of this group are SARS-CoV-2 (coronavirus), HIV (human immunodeficiency virus), EBOV (Ebola virus), DENV (dengue virus), HCV (hepatitis C virus), ZIKV (Zika virus), CHIKV (chikungunya virus), and influenza A virus. With the exception of retroviruses which produce reverse transcriptase, the majority of RNA viruses encode RNA-dependent RNA polymerases which do not include molecular proofreading tools, underlying the high mutation capacity of these viruses as they multiply in the host cells. Together with their ability to manipulate the immune system of the host in different ways, their high mutation frequency poses a challenge to develop effective and durable vaccination and/or treatments. Consequently, the use of antiviral targeting agents, while an important part of the therapeutic strategy against infection, may lead to the selection of drug-resistant variants. The crucial role of the host cell replicative and processing machinery is essential for the replicative cycle of the viruses and has driven attention to the potential use of drugs directed to the host machinery as therapeutic alternatives to treat viral infections. In this review, we discuss small molecules with antiviral effects that target cellular factors in different steps of the infectious cycle of many RNA viruses. We emphasize the repurposing of FDA-approved drugs with broad-spectrum antiviral activity. Finally, we postulate that the ferruginol analog (18-(phthalimide-2-yl) ferruginol) is a potential host-targeted antiviral.

New 1,4-anthracenediones bearing fused-heterocycle rings were synthesized and evaluated as cytotoxics, antifungals and antivirals. Some of them showed GI₅₀ at the μM level.

Interest in medicinal and aromatic plants as a source of antimicrobial drugs has emerged, mainly due to increased resistance of infectious agents. In this study, the antifungal and cytotoxic activity of thirteen essential oils and nine extracts of plants of the genus Piper, from Colombia, were evaluated. The Piper hispidum Sw oil showed activity against the multi-resistant fungus Fusarium oxysporum. Six samples showed strong activity against dermatophytes, being Piper bogotense the most active, followed by P. hispidum. The oils from Piper hispidum, Piper coruscans, Piper marginatum and Piper cf. divaricatum, and the extract from Piper sanctifelicis, were not cytotoxic, unlike Piper bredemeyeri, Piper eriopodon and Piper bogotense oils, which exhibited significant cytotoxicity. The main components of the most active samples showed the presence of trans-β-caryophyllene. In addition, caryophyllene oxide, β-pinene and α-pinene were present in most antifungal oils at different concentrations. These results confirm the anti-mycotic potential of essential oils of the Piper genus against the most pathogenic fungi, as well as against important dermatological fungi.