Integrated Analytical Tools for Accessing Acridones and Unrelated Phenylacrylamides from Swinglea glutinosa.

In natural product studies, the purification of metabolites is an important challenge. To accelerate this step, alternatives such as integrated analytical tools should be employed. Based on this, the chemical study of Swinglea glutinosa (Rutaceae) was performed using two rapid dereplication strategies: Target Analysis (Bruker Daltonics®, Bremen, Germany) MS data analysis combined with MS/MS data obtained from the GNPS platform. Through UHPLC-HRMS data, the first approach allowed, from crude fractions, a quick and visual identification of compounds already reported in the Swinglea genus. Aside from this, by grouping compounds according to their fragmentation patterns, the second approach enabled the detection of eight molecular families, which presented matches for acridonic alkaloids, phenylacrylamides, and flavonoids. Unrelated compounds for S. glutinosa have been isolated and characterized by NMR experiments, Lansamide I, Lansiumamide B, Lansiumamide C, and N-(2-phenylethyl)cinnamamide.

Importance of retention data from affinity and reverse-phase high-performance liquid chromatography on antitumor activity prediction of imidazoacridinones using QSAR strategy.

Quantitative structure-activity relationships (QSAR) studies for prediction of cytotoxic and antitumor activity of imidazoacridinones (IA) based on experimentally obtained high-performance liquid chromatography (HPLC) retention data and calculated parameters using computational (molecular modeling) medicinal chemistry methods were proposed. The RP-HPLC and affinity-HPLC chromatographic techniques with four diversified HPLC systems applying columns with octadecylsilanes (C18), phosphatidylcholine (IAM), as well as α(1)-glycoprotein (AGP) and albumin (HSA) were used for the determination of the retention constants logk and logk(w) which characterize lipophilicity and protein affinity of IA. Moreover, molecular modeling studies were performed using HyperChem and Dragon software's, and structural descriptors were calculated and subsequently used. The QSAR equations using multiple linear regression (MLR) analysis method were derived which indicated that in vivo antileukemia activity of IA depends on cytotoxic activity against leukemia cells, whereas this cytotoxic activity depends on logk and logk(w) parameters obtained on all HPLC systems. Moreover, the QSRR equations were derived and indicated that logk and logk(w) parameters depend on calculated non-empirical structural parameters. The predictive power of obtained QSAR and QSRR equations allowed the prediction of cytotoxic and antitumor activity of IA and also their HPLC retention parameters. Finally, the equations can be used for prediction of antileukemia activity of IA without the necessity of carrying out experimental measurements.

Discovery of dual function acridones as a new antimalarial chemotype.

Preventing and delaying the emergence of drug resistance is an essential goal of antimalarial drug development. Monotherapy and highly mutable drug targets have each facilitated resistance, and both are undesirable in effective long-term strategies against multi-drug-resistant malaria. Haem remains an immutable and vulnerable target, because it is not parasite-encoded and its detoxification during haemoglobin degradation, critical to parasite survival, can be subverted by drug-haem interaction as in the case of quinolines and many other drugs. Here we describe a new antimalarial chemotype that combines the haem-targeting character of acridones, together with a chemosensitizing component that counteracts resistance to quinoline antimalarial drugs. Beyond the essential intrinsic characteristics common to deserving candidate antimalarials (high potency in vitro against pan-sensitive and multi-drug-resistant Plasmodium falciparum, efficacy and safety in vivo after oral administration, inexpensive synthesis and favourable physicochemical properties), our initial lead, T3.5 (3-chloro-6-(2-diethylamino-ethoxy)-10-(2-diethylamino-ethyl)-acridone), demonstrates unique synergistic properties. In addition to 'verapamil-like' chemosensitization to chloroquine and amodiaquine against quinoline-resistant parasites, T3.5 also results in an apparently mechanistically distinct synergism with quinine and with piperaquine. This synergy, evident in both quinoline-sensitive and quinoline-resistant parasites, has been demonstrated both in vitro and in vivo. In summary, this innovative acridone design merges intrinsic potency and resistance-counteracting functions in one molecule, and represents a new strategy to expand, enhance and sustain effective antimalarial drug combinations.