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Natural products (or specialized metabolites) are historically the main source of new drugs. However, the current drug discovery pipelines require miniaturization and speeds that are incompatible with traditional natural product research methods, especially in the early stages of the research. This article introduces the NP3 MS Workflow, a robust open-source software system for liquid chromatography-tandem mass spectrometry (LC-MS/MS) untargeted metabolomic data processing and analysis, designed to rank bioactive natural products directly from complex mixtures of compounds, such as bioactive biota samples. NP3 MS Workflow allows minimal user intervention as well as customization of each step of LC-MS/MS data processing, with diagnostic statistics to allow interpretation and optimization of LC-MS/MS data processing by the user. NP3 MS Workflow adds improved computing of the MS2 spectra in an LC-MS/MS data set and provides tools for automatic [M + H]+ ion deconvolution using fragmentation rules; chemical structural annotation against MS2 databases; and relative quantification of the precursor ions for bioactivity correlation scoring. The software will be presented with case studies and comparisons with equivalent tools currently available. NP3 MS Workflow shows a robust and useful approach to select bioactive natural products from complex mixtures, improving the set of tools available for untargeted metabolomics. It can be easily integrated into natural product-based drug-discovery pipelines and to other fields of research at the interface of chemistry and biology.

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Resumen: La malposición de los catéteres venosos centrales se asocia a importantes riesgos, a menudo infraestimados. Aunque se han descrito algunos factores que pueden favorecer la malposición, generalmente su causa no llega a diagnosticarse y parece ser de origen multifactorial. Presentamos dos casos de malposición de catéteres venosos centrales motivadas por causas anatómicas inusuales, diagnosticadas en el perioperatorio. En el primer caso, se diagnostica una agenesia de vena cava superior en el transcurso de una sustitución mitral por esternotomía, que lógicamente se asocia con una malposición de la vía central insertada. La utilización de catéteres y dispositivos a través de venas yugulares y subclavias en pacientes con esta infrecuente patología implica importantes limitaciones y complicaciones potenciales graves. En el segundo caso, la existencia de un bocio no diagnosticado provoca la malposición bilateral y simultánea de dos catéteres venosos canalizados, en el contexto de una situación de emergencia, en ambas venas yugulares internas.

Abstract: Malposition of central venous catheters is associated with important and underestimated risks. Although some factors have been related with malposition, its cause is generally not diagnosed, and it seems to have multifactorial origin. We present two cases of central venous catheter malposition due to unusual anatomical causes, diagnosed in the perioperative period. In the first case, superior vena cava agenesis was diagnosed during mitral replacement by sternotomy, which was logically associated with malposition of the inserted central line. The use of catheters and devices through jugular and subclavian veins in patients with this infrequent pathology is associated with important limitations and serious potential complications. In the second case, an undiagnosed goiter causes bilateral and simultaneous malpositioning of two inserted central venous catheters, in the context of an emergency situation, in both internal jugular veins.

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The F1FO-ATP synthase nanomotor synthesizes >90% of the cellular ATP of almost all living beings by rotating in the "forward" direction, but it can also consume the same ATP pools by rotating in "reverse." To prevent futile F1FO-ATPase activity, several different inhibitory proteins or domains in bacteria (ε and ζ subunits), mitochondria (IF1), and chloroplasts (ε and γ disulfide) emerged to block the F1FO-ATPase activity selectively. In this study, we analyze how these F1FO-ATPase inhibitory proteins have evolved. The phylogeny of the α-proteobacterial ε showed that it diverged in its C-terminal side, thus losing both the inhibitory function and the ATP-binding/sensor motif that controls this inhibition. The losses of inhibitory function and the ATP-binding site correlate with an evolutionary divergence of non-inhibitory α-proteobacterial ε and mitochondrial δ subunits from inhibitory bacterial and chloroplastidic ε subunits. Here, we confirm the lack of inhibitory function of wild-type and C-terminal truncated ε subunits of P. denitrificans. Taken together, the data show that ζ evolved to replace ε as the primary inhibitor of the F1FO-ATPase of free-living α-proteobacteria. However, the ζ inhibitory function was also partially lost in some symbiotic α-proteobacteria and totally lost in some strictly parasitic α-proteobacteria such as the Rickettsiales order. Finally, we found that ζ and IF1 likely evolved independently via convergent evolution before and after the endosymbiotic origin mitochondria, respectively. This led us to propose the ε and ζ subunits as tracer genes of the pre-endosymbiont that evolved into the actual mitochondria.

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Lamivudine, also widely known as 3TC belongs to a family of nucleotide/nucleoside analogues of cytidine or cytosine that inhibits the Reverse Transcriptase (RT) of retroviruses such as HIV. Lamivudine is currently indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection or for chronic Hepatitis B (HBV) virus infection associated with evidence of hepatitis B viral replication and active liver inflammation. HBV reactivation in patients with HBV infections who receive anticancer chemotherapy can be a life-threatening complication during and after the completion of chemotherapy. Lamivudine is used, as well as other antiretrovirals, to prevent the reactivation of the Hepatitis B virus during and after chemotherapy. In addition, Lamivudine has been shown to sensitize cancer cells to chemotherapy. Lamivudine and other similar analogues also have direct positive effects in the prevention of cancer in hepatitis B or HIV positive patients, independently of chemotherapy or radiotherapy. Recently, it has been proposed that Lamivudine might be also repurposed against SARS-CoV-2 in the context of the COVID-19 pandemic. In this review we first examine recent reports on the re-usage of Lamivudine or 3TC against the SARS-CoV-2, and we present docking evidence carried out in silico suggesting that Lamivudine may bind and possibly work as an inhibitor of the SARS-CoV-2 RdRp RNA polymerase. We also evaluate and propose assessment of repurposing Lamivudine as anti-SARS-CoV-2 and anti-COVID-19 antiviral. Secondly, we summarize the published literature on the use of Lamivudine or (3TC) before or during chemotherapy to prevent reactivation of HBV, and examine reports of enhanced effectiveness of radiotherapy in combination with Lamivudine treatment against the cancerous cells or tissues. We show that the anti-cancer properties of Lamivudine are well established, whereas its putative anti-COVID effect is under investigation. The side effects of lamivudine and the appearance of resistance to 3TC are also discussed.

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The ATP synthase is a ubiquitous nanomotor that fuels life by the synthesis of the chemical energy of ATP. In order to synthesize ATP, this enzyme is capable of rotating its central rotor in a reversible manner. In the clockwise (CW) direction, it functions as ATP synthase, while in counter clockwise (CCW) sense it functions as an proton pumping ATPase. In bacteria and mitochondria, there are two known canonical natural inhibitor proteins, namely the ε and IF1 subunits. These proteins regulate the CCW F1FO-ATPase activity by blocking γ subunit rotation at the αDP/ßDP/γ subunit interface in the F1 domain. Recently, we discovered a unique natural F1-ATPase inhibitor in Paracoccus denitrificans and related α-proteobacteria denoted the ζ subunit. Here, we compare the functional and structural mechanisms of ε, IF1, and ζ, and using the current data in the field, it is evident that all three regulatory proteins interact with the αDP/ßDP/γ interface of the F1-ATPase. In order to exert inhibition, IF1 and ζ contain an intrinsically disordered N-terminal protein region (IDPr) that folds into an α-helix when inserted in the αDP/ßDP/γ interface. In this context, we revised here the mechanism and role of the ζ subunit as a unidirectional F-ATPase inhibitor blocking exclusively the CCW F1FO-ATPase rotation, without affecting the CW-F1FO-ATP synthase turnover. In summary, the ζ subunit has a mode of action similar to mitochondrial IF1, but in α-proteobacteria. The structural and functional implications of these intrinsically disordered ζ and IF1 inhibitors are discussed to shed light on the control mechanisms of the ATP synthase nanomotor from an evolutionary perspective.

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