A review on the structures and biological activities of anti-Helicobacter pylori agents.

Helicobacter pylori is one of the main causal risk factor in the generation of chronic gastritis, gastroduodenal ulcers and gastric carcinoma. Thus, the eradication of H. pylori infection is an important way for preventing and managing the gastric diseases. Multiple-therapy with several antibacterial agents is used for the eradication of H. pylori infections; however the increase of resistance to H. pylori strains has resulted in unsatisfactory eradication and unsuccessful treatment. Furthermore, the combination therapy with high dosing leads to the disruption of intestinal microbial flora and undesired side effects. Therefore, the search for new therapeutic agents with high selectivity against H. pylori is a field of current interest. In recent years, diverse compounds originating from natural sources or synthetic drug design programs were evaluated and tried to optimize for applying against H. pylori. In this review, we have described various classes of anti-H. pylori compounds, their structure-activity relationship studies, and mechanism of actions, which could be useful for the development of new drugs for the treatment of H. pylori infections.

Current development of sigma-2 receptor radioligands as potential tumor imaging agents.

Sigma receptors are transmembrane proteins with two different subtypes: σ1 and σ2. Because of its overexpression in tumors, the σ2 receptor (σ2R) is a well-known biomarker for cancer cells. A large number of small-molecule ligands for the σ2Rs have been identified and tested for imaging the proliferative status of tumors using single photon emission computed tomography (SPECT) and positron emission tomography (PET). These small molecules include derivatives of bicyclic amines, indoles, cyclohexylpiperazines and tetrahydroisoquinolines. This review discusses various aspects of small molecule ligands, such as chemical composition, labeling strategy, affinity for σ2Rs, and in vitro/in vivo investigations. The recent studies described here could be useful for the development of σ2R radioligands as potential tumor imaging agents.

A review on traditional uses, phytochemistry and pharmacological activities of the genus Ballota.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Ballota L. (Lamiaceae) comprises 33 to 35 species distributed mainly in temperate and subtropical regions of the world. Some species have been used in folk medicine as antiemetic, antispasmodic, sedative agents, vermifuge, antihemorrhoid and also in treatment of cough, etc. AIM OF THIS REVIEW: This review article aims to provide organized information on the available traditional uses, phytochemical and pharmacological studies of the genus Ballota, and to obtain new insights for further researches. MATERIALS AND METHODS: Electronic databases, including Web of Science, Science Direct, Google Scholar, Scopus, PubMed, and Springer Link were used as information sources. General web searches were carried out using Google and Yahoo search engines by applying related search terms. Additional information was derived from books and journals in English, Latin and Persian, and also Ph.D. theses and M.Sc. dissertations. RESULTS: Terpenoids (particularly furanolabdane diterpenoids) and flavonoids were the main phytochemical classes identified in the extracts of Ballota species. Furanolabdane diterpenoids, e.g. ballonigrin, dehydrohispanolone, and hispanolone were reported in many species of Ballota. ß-Caryophyllene, caryophyllene oxide, and germacrene D were found as the most common major compounds isolated from the essential oils of the genus Ballota. Sixty-four pharmacological studies conducted on cell lines, microorganisms, and animals were included in this review. Some species of Ballota exhibited various pharmacological activities, including promising antidepressant, anxiolytic, sedative-hypnotic, and antitussive activities in animal models. The pharmacological activities can be attributed to bioactive phytochemicals. CONCLUSION: The genus Ballota is a valuable source of bioactive compounds with therapeutic potential in different diseases. Some pharmacological studies showed incomplete methodologies and ambiguous findings. Thus, the research designs of pharmacological studies based on traditional uses of Ballota species are strongly needed in cell lines and animal models. More in vitro and in vivo animal studies are required to confirm the safety, clarification of the effective doses, bioactive compounds, and the mechanisms of actions before future clinical studies.

Design, synthesis, biological assessment and molecular docking studies of new 2-aminoimidazole-quinoxaline hybrids as potential anticancer agents.

In a search for novel antiproliferative agents, a series of quinoxaline derivatives containing 2-aminoimidazole (8a-8x) were designed and synthesized. The structures of synthesized compounds were confirmed by IR, 1H NMR, 13C NMR, Mass Spectroscopy and analyzed using HSQC, COSY, ROESY, HMBC techniques. The anticancer activity of all derivatives were evaluated for colon cancer and breast cancer cell lines by the MTT assay and acridine orange/ethidium bromide double staining method. The anti-cancer effect in human colon cancer (HCT-116) and breast cancer (MCF-7) cell lines exhibited that compounds 8a, 8s, 8t, 8w, 8x appeared as potent antiproliferative agents and especially inhibited the human colon cancer cell proliferation with percentage of inhibition by over 50%. The most active compound was (E)-4-phenyl-1-((quinoxalin-2-ylmethylene)amino)-1H-imidazol-2-amine (8a) with the highest inhibition for MCF-7 (83.3%) and HCT-116 (70%) cell lines after 48 and 24h, respectively. Molecular docking studies of these derivatives within c-kit active site as a validated target might be suggested them as appropriate candidates for further efforts toward more potent anticancer compounds.

Recent advances of chroman-4-one derivatives: synthetic approaches and bioactivities.

Chroman-4-one scaffold is a privileged structure in heterocyclic chemistry and drug discovery. Also, chroman-4-ones are important intermediates and interesting building blocks in organic synthesis and drug design. The structural diversity found in the chroman-4-one family led to their division into several categories including benzylidene-4-chromanones, flavanones (2-phenyl-4-chromanones), isoflavanones (3-phenyl-4-chromanones), spirochromanones, and C-4 modified chroman-4-ones such as hydrazones and oxime derivatives. This review addresses the most significant synthetic methods reported on 4-chromanone-derived compounds and consequently emphasizes on the biological relevance of such compounds.