Design and synthesis of substituted morpholin/piperidin-1-yl-carbamodithioates as promising vaginal microbicides with spermicidal potential

From dithiocarbamates to branched dithiocarbazates: Compounds with potent antischistosomal activity

Schistosomiasis or bilharzia is caused by blood flukes of the genus Schistosoma and represents a considerable health and economic burden in tropical and subtropical regions. The treatment of this infectious disease relies on one single drug: praziquantel (PZQ). Therefore, new and potent antischistosomal compounds need to be developed. In our previous work, starting with the drug disulfiram, we developed dithiocarbamates with in vitro antischistosomal activities in the low micromolar range. Based on these results, we report in this study on the synthesis and biological testing of the structurally related dithiocarbazates against Schistosoma mansoni, one of the major species of schistosomes. In total, three series of dithiocarbazate derivatives were examined, and we found that the antischistosomal activity of N-unbranched dithiocarbazates increased by further N-substitution. Comparable tetra-substituted dithiocarbazates were rarely described in the literature, thus a synthesis route was established. Due to the elaborate synthesis, the branched dithiocarbazates (containing an N-aminopiperazine) were simplified, but the resulting branched dithiocarbamates (containing a 4-aminopiperidine) were considerably less active. Taken together, dithiocarbazate-containing compounds with an in vitro antischistosomal activity of 5 µM were obtained.

Chemotherapeutic options for the treatment of human trichomoniasis

Trichomonas vaginalis is the causative agent of the most common non-viral sexually transmitted disease worldwide. The infection may be associated with severe complications, including infertility, preterm labour, cancer and an increased risk of human immunodeficiency virus (HIV) transmission. Treatment remains almost exclusively based on 5-nitroimidazoles, but resistance is on the rise. This article provides an overview of clinically evaluated systemic and topical treatment options for human trichomoniasis and summarises the current state of knowledge on various herbal, semisynthetic and synthetic compounds evaluated for their anti-Trichomonas efficacy in vitro.

Substituted carbamothioic amine-1-carbothioic thioanhydrides as novel trichomonicidal fungicides: Design, synthesis, and biology

Sexually transmitted diseases like trichomoniasis along with opportunistic fungal infections like candidiasis are major global health burden in female reproductive health. In this context a novel non-nitroimidazole class of substituted carbamothioic amine-1-carbothioic thioanhydride series was designed, synthesized, evaluated for trichomonacidal and fungicidal activities, and was found to be more active than the standard drug Metronidazole (MTZ). Compounds were trichomonicidal in the MIC ranges of 4.77-294.1 μM and 32.46-735.20 μM against MTZ-susceptible and -resistant strains, respectively. Further, compounds inhibited the growth of at least two out of ten fungal strains tested at MIC of 7.50-240.38 μM. The most active compound (20) of this series was 3.8 and 9.5 fold more active than the MTZ against the two Trichomonas strains tested. Compound 20 also significantly inhibited the sulfhydryl groups present over Trichomonas vaginalis and was found to be more active than the MTZ in vivo. Further, a docking analysis carried out with cysteine proteases supported their thiol inhibiting ability and preliminary pharmacokinetic study has shown good distribution and systemic clearance.

Recent developments in anti-Trichomonas research: An update review

Trichomonas vaginalis is a major non-viral sexually-transmitted infection resulted into serious obstetrical and gynecological troubles. The increasing resistance to nitroimidazole therapy and recurrence makes it crucial to develop new drugs against trichomoniasis. Over the past few years, a large number of research articles highlighting the synthetic and natural product research to combat Trichomonas vaginalis have been published. Electronic databases were searched to collect all data from the year 2006 through June 2017 for anti-Trichomonas activity potential of synthetic and natural products. This review article put together the synthetic and natural product research to find out an effective metronidazole alternative to cure trichomoniasis.

Innovative Disulfide Esters of Dithiocarbamic Acid as Women-Controlled Contraceptive Microbicides: A Bioisosterism Approach

In an ongoing effort to discover an effective, topical, dual-function, non-surfactant contraceptive vaginal microbicide, a novel series of 2,2'-disulfanediylbis(3-(substituted-1-yl)propane-2,1-diyl) disubstituted-1-carbodithioates were designed by using a bioisosterism approach. Thirty-three compounds were synthesized, and interestingly, most demonstrated multiple activities: they were found to be spermicidal at a minimal effective concentration of 1-0.001 %, trichomonacidal against drug-susceptible and resistant Trichomonas strains at minimal inhibitory concentration (MIC) ranges of 10.81-377.64 and 10.81-754.14 μM, respectively, and fungicidal at MIC 7.93-86.50 μM. These compounds were also found to be non-cytotoxic to human cervical (HeLa) epithelial cells and vaginal microflora (Lactobacilli) in vitro. The most promising compound, 2,2'-disulfanediylbis(3-(pyrrolidin-1-yl)propane-2,1-diyl)dipyrrolidine-1-carbodithioate (5), exhibited spermicidal activity 15-fold higher than that of the marketed spermicide Nonoxynol-9 (N-9) and also demonstrated microbicidal potency. To identify common structural features required for spermicidal activity, a 3D-QSAR analysis was carried out, as well as in vivo efficacy studies and fluorescent labeling studies to determine the biological targets of compound 5.

Natural and synthetic compound anti-Trichomonas vaginalis: an update review

Trichomonas vaginalis is a flagellate protozoan that causes trichomonosis, a sexually transmitted disease of worldwide importance. However, the infection has long received much less attention than other parasitic and sexually transmitted diseases. This negligence leads to poor diagnosis and underestimated prevalence values, and consequently, it has been associated to increasing acquisition and transmission of HIV, pregnancy outcomes, infertility, pelvic inflammatory disease, and cervical and prostate cancer. In view of increased resistance to drugs belonging to the nitroimidazole class, new treatment alternatives are urgently needed. Natural products provide an immeasurable wealth of active molecules, and a great number of new drugs have been originated from these compounds. In addition, new synthetic products or derivatives from old drugs also provide an alternative to treat trichomonosis. Albeit many studies have been performed with natural products against T. vaginalis, none of them progressed to clinical trials. Overall, inadequate financial investments are made, and no alternative treatment for trichomonosis has been discovered; meanwhile, hundreds of thousands of people will remain infected and suffering the serious consequences of this nonviral STD. Thus, it is highlighted that clinical trials for better understanding the potential in vitro are necessary and urgent in order to furnish a new therapeutic alternative for trichomonosis treatment. The current review attempts to give an overview on the potential of natural and synthetic products as antitrichomonal.