Lipophilicity assessement in drug discovery: Experimental and theoretical methods applied to xanthone derivatives.

For the last several years, searching of new xanthone derivatives (XDs) with potential pharmacological activities has remained one of the main areas of interest of our group. The optimization of biological activity and drug-like properties of hits and leads is crucial at early stage of the drug discovery pipeline. Lipophilicity is one of the most important drug-like properties having a great impact in both pharmacokinetics and pharmacodynamics processes. In this work, we describe the lipophilicity of a small library of bioactive XDs, previously synthesized by our group, using different methods: computational, vortex-assisted liquid-liquid microextraction coupled with high-performance liquid chromatography (VALLME-HPLC), reversed-phase high-performance thin layer chromatography (RP-HPTLC), reversed-phase high-performance liquid chromatography (RP-HPLC), and biomembrane model by the partition between micelles and aqueous phase. The different results obtained by the used methods were compared and discussed. The methodologies and data gathered in this study will expand the investigation of lipophilicity of XDs, an important class of compounds in medicinal chemistry.

Street-Like Synthesis of Krokodil Results in the Formation of an Enlarged Cluster of Known and New Morphinans.

"Krokodil" is the street name for a homemade injectable drug that has been used as a cheap substitute for heroin. Codeine is the opioid starting material for krokodil synthesis, and desomorphine is claimed to be the main opioid of krokodil and the main component responsible for its addictive and psychoactive characteristics. However, due to its peculiar manufacture, using cheap raw materials, krokodil is composed of a large and complex mixture of different substances. In order to shed some light upon the chemical complexity of krokodil, its profiling was conducted by reverse phase high performance liquid chromatography coupled to a photodiode array detector (RP-HPLC-DAD) and by liquid chromatography coupled to high resolution tandem mass spectrometry (LC-ESI-IT-Orbitrap-MS). Besides desomorphine, codeine, and morphine, profiting from the high resolution mass spectrometry (HRMS) data, an endeavor to study the morphinans content in krokodil was set for the first time. Considering codeine as the only morphinan precursor and the possible chemical transformations that can occur during krokodil synthesis, the morphinan chemical space was designed, and 95 compounds were defined. By making use of the morphinan chemical space in krokodil, the exact masses featured by HRMS, and the morphinan mass fragmentations patterns, a targeted identification approach was designed and implemented.The proposed 95 morphinans were searched using the full scan chromatogram of krokodil, and findings were validated by mass fragmentation of the correspondent precursor ions (MS2 spectra). Following this effort, a total of 54 morphinans were detected, highlighting the fact that these additional morphinans may contribute to the psychotropic effects of krokodil.

Repeated subcutaneous administrations of krokodil causes skin necrosis and internal organs toxicity in Wistar rats: putative human implications.

OBJECTIVE: "Krokodil" is the street name for an impure homemade drug mixture used as a cheap substitute for heroin, containing desomorphine as the main opioid. Abscesses, gangrene, thrombophlebitis, limb ulceration and amputations, jaw osteonecrosis, skin discoloration, ulcers, skin infections, and bleeding are some of the typical reported signs in humans. This study aimed to understand the toxicity of krokodil using Wistar male rats as experimental model. METHODS: Animals were divided into seven groups and exposed subcutaneously to NaCl 0.9% (control), krokodil mixture free of psychotropic substances (blank krokodil), pharmaceutical grade desomorphine 1 mg/kg, and four different concentrations of krokodil (containing 0.125, 0.25, 0.5, and 1 mg/kg of desomorphine) synthesized accordingly to a "domestic" protocol followed by people who inject krokodil (PWIK). Daily injections for five consecutive days were performed, and animals were sacrificed 24 hr after the last administration. Biochemical and histological analysis were carried out. RESULTS: It was shown that the continuous use of krokodil may cause injury at the injection area, with formation of necrotic zones. The biochemical results evidenced alterations on cardiac and renal biomarkers of toxicity, namely, creatine kinase, creatine kinase-MB, and uric acid. Significant alteration in levels of reduced and oxidized glutathione on kidney and heart suggested that oxidative stress may be involved in krokodil-mediated toxicity. Cardiac congestion was the most relevant finding of continuous krokodil administration. CONCLUSIONS: These findings contribute notably to comprehension of the local and systemic toxicological impact of this complex drug mixture on major organs and will hopefully be useful for the development of appropriate treatment strategies towards the human toxicological effects of krokodil.

Data analysis of "krokodil" samples obtained by street-like synthesis.

The data described in this work is related to be the subject of an article in the Forensic Science International, titled: "The harmful chemistry behind "krokodil": street-like synthesis and product analysis" (http://dx.doi.org/10.1016/j.forsciint.2015.07.042) [1]. The data presented here provides additional description of the chemical profile of "krokodil". Physicochemical and organoleptic characteristics, TLC profile, UV/Vis, (1)H NMR and FTIR spectrum are presented. These data validate the proposed synthetic procedure and pathway and give further information about the contaminants present in "krokodil".

The harmful chemistry behind "krokodil": Street-like synthesis and product analysis.

"Krokodil" is the street name for a drug, which has been attracting media and researchers attention due to its increasing spread and extreme toxicity. "Krokodil" is a homemade injectable mixture being used as a cheap substitute for heroin. Its use begun in Russia and Ukraine, but it is being spread throughout other countries. The starting materials for "krokodil" synthesis are tablets containing codeine, caustic soda, gasoline, hydrochloric acid, iodine from disinfectants and red phosphorus from matchboxes, all of which are easily available in a retail market or drugstores. The resulting product is a light brown liquid that is injected without previous purification. Herein, we aimed to understand the chemistry behind "krokodil" synthesis by mimicking the steps followed by people who use this drug. The successful synthesis was assessed by the presence of desomorphine and other two morphinans. An analytical gas chromatography-electron impact/mass spectrometry (GC-EI/MS) methodology for quantification of desomorphine and codeine was also developed and validated. The methodologies presented herein provide a representative synthesis of "krokodil" street samples and the application of an effective analytical methodology for desomorphine quantification, which was the major morphinan found. Further studies are required in order to find other hypothetical by-products in "krokodil" since these may help to explain signs and symptoms presented by abusers.