Hiroki Terauchi

Bio: Hiroki Terauchi is an academic researcher from Tohoku University. The author has contributed to research in topics: Profiling (computer programming) & Antimalarial Agent. The author has an hindex of 5, co-authored 10 publications receiving 110 citations. Previous affiliations of Hiroki Terauchi include Okayama University.

Antileishmanial Activities of Rhodacyanine Dyes

Abstract: Rhodacyanine dyes, potent antimalarial agents, was found to possess strong antileishmanial activity against Leishmania major in vitro. The efficacies of several compounds are comparable to one of clinically used amphotericin B.

Selective accumulation of rhodacyanine in plasmodial mitochondria is related to the growth inhibition of malaria parasites

Abstract: Fluorescent rhodacyanines, which display antimalarial activity in vitro and in vivo, stain plasmodial parasites at the erythrocytic stage. A good correlation between the antimalarial activity and the accumulation of the dyes is observed. A fused-rhodacyanine, which displays a strong fluorescent property itself, was designed as a new probe for plasmodial parasites. It appears to be specifically localized in the parasitic mitochondria.

Anti-leishmania agent

Abstract: PROBLEM TO BE SOLVED: To obtain a new anti-Leishmania agent that has slight adverse effect, high inhibitory action of cell growth on Leishmania protozoans, is readily produced and inexpensively supplied. SOLUTION: The anti-Leishmania agent is obtained by using a compound having a heterocycle containing a conjugated system and a nitrogen atom and a carbon chain containing an ethylene group, namely a compound in which a specific 5- to 8-membered heterocycle and a specified 5- to 8-membered heterocycle containing a conjugated system are bonded through a vinylene group, more in detail, a specified rhodacyanine-based coloring matter compound as an active ingredient for an anti-Leishmania agent. COPYRIGHT: (C)2005,JPO&NCIPI

Recent developments in drug discovery for leishmaniasis and human African trypanosomiasis.

Abstract: Leishmaniasis is a parasitic disease that presents four main clinical syndromes: cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), visceral leishmaniasis/kala azar (VL), and post kala azar dermal leishmaniasis (PKDL). Causative Leishmania are protozoan parasites that are transmitted among mammalian hosts by phlebotomine sandflies. In mammalian hosts, parasite cells proliferate inside the host phagocytic cells as round amastigotes. Infection of sandflies with Leishmania occurs during insect feeding on infected mammalian hosts. After introduction into the insect gut together with the blood meal, Leishmania amastigotes transform into elongated flagellated promastigotes that propagate in the insect gut. A new round of infection is initiated after the infected sandfly takes a blood meal from a naive mammalian host and introduces Leishmania parasites into the bite wound in the host dermis (Scheme 1). More than 20 different Leishmania species have been found to cause human leishmaniasis (Table 1). Leishmaniasis is endemic in 98 countries and is closely associated with poverty. More than a million new cases are reported per year and 350 million people are at risk of contracting the infection. For the most severe form of leishmaniasis, VL, ∼300 000 new cases are estimated to occur annually resulting in ∼40 000 deaths. Approximately 90% of all VL cases occur in 3 endemic foci: 1. India, Bangladesh, and Nepal; 2. East Africa; and 3. Brazil. In spite of the high prevalence, currently available treatments for leishmaniasis are inadequate. Pentavalent antimonials, the standard treatment for leishmaniasis for many decades, are not efficacious in Bihar (∼60% of VL cases worldwide) any longer due to widespread resistance to the drug in this region. Several new VL treatments have emerged during the past 10–15 years, but each has serious shortcomings (summarized in Table 2). These include paromomycin (injectable, long treatment, region-dependent efficacy), miltefosine (cost, teratogenicity, long treatment), and liposomal amphotericin B (cost, hospitalization, region-dependent efficacy). An additional challenge is represented by patients with HIV/VL coinfections who are more difficult to cure (lower initial and final cure rates), have greater susceptibility to drug toxicity, and have higher rates of death and relapse. Due to the limitations of the existing treatments, better drugs are urgently needed. Ideally, new VL drugs would be efficacious across all endemic regions, would affect cure in ≤10 days, and would cost <$10 per course (for a complete target product profile for new VL drugs, which was formulated by DNDi, see Table 4).1 Here we describe the disease history and parasite biology followed by a summary of the currently available treatments and, finally, review reports of novel small molecules with antileishmanial activity.

Medicinal significance of benzothiazole scaffold: an insight view

Abstract: Heterocycles bearing nitrogen, sulphur and thiazole moieties constitute the core structure of a number of biologically interesting compounds. Benzothiazole, a group of xenobiotic compounds containing a benzene ring fused with a thiazole ring, are used worldwide for a variety of therapeutic applications. Benzothiazole and their heterocyclic derivatives represent an important class of compounds possessing a wide spectrum of biological activities. The myriad spectrum of medicinal properties associated with benzothiazole related drugs has encouraged the medicinal chemists to synthesize a large number of novel therapeutic agents. Several analogues containing benzothiazole ring system exhibit significant antitumour, antimicrobial, antidiabetic, anti-inflammatory, anticonvulsant, antiviral, antioxidant, antitubercular, antimalarial, antiasthmatic, anthelmintic, photosensitizing, diuretic, analgesic and other activities. This article is an attempt to present the research work reported in recent scientific literat...