Bulaquine a CDRI India Antimalarial

Bulaquine

CAS NO.: 79781-00-3

2(3H)-Furanone, dihydro-3-(1-((4-((6-methoxy-8-quinolinyl)amino)pentyl)amino)ethylidene)-,

 3-[l-[[4-[(6-methoxy-8-quinolinyl)amino]pentyl]amino]- ethyMene]-dihydro-2(3H)furanone

N¹- (3-ethylidinotetrahydrofuran-2-one)-N⁴- (6-methoxy-8-quinolinyl)-1,4-pentanediamine

• Nicholas Piramal India Ltd
• Council Of Scient & Ind Res 

BULAQUINE

https://www.ncbi.nlm.nih.gov/pubmed?cmd=search&term=%22bulaquine%22%5BNM%5D

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http://www.google.com/patents/EP1292306A2?cl=en

Malaria, caused by a parasitic protozoan called Plasmodium, is one of the most serious and complex tropical parasitic diseases. Generally human malaria is caused by four species of malarial parasites which are Plasmodium falciparwn, Plasmodium vivax, Plasmodium ovale and Plasmodium malariae. Of these P. falciparum and P. vivαx are most widespread and cause most of the mortality and morbidity associated with these types of infections.

It is known that the malarial parasites undergo complex life cycle in humans, which is initiated through the bite of an infected female Anopheles mosquito. When the mosquito bites a host, some of the sporozoites are injected into the bloodstream of the host and through the circulation they reach the liver where they multiply and liberate merozoites into the bloodstream which then invade the erythrocytes. In case of infections caused by P. vivαx, most of the time the parasites remain dormant in the liver which stage is termed hypnozoites. Hypnozoites are reactivated and reinitiate blood stage parasitemias causing relapse. It has often been observed that people infected with P. vivax do not experience any symptoms for a very long period after their initial illness but become symptomatic after certain period (Korean J. Intern Med, 1999 Juk 14(2): 86-9).

A number of drugs ranging from those of natural origin to synthetic ones have been developed for the treatment of malaria. Quinine and artemisinin are the commonly known drugs of natural origin, which are mostly used for the treatment of malaria. A number of synthetic anti- malarial drugs such as chloroquine, mefloquine, primaquine, halofantrine, ainodiaquine, proguanil, maloprim are known in the literature. Of all the synthetic anti-malarial agents chloroquine has been the most widely prescribed drug for the treatment of malaria of all the types, for more than last 60 years.

Chloroquine has been the effective treatment so far for the P. vivax malarial infections, however, some strains of P. vivax have shown resistance to this well known drug {Ann. Trop. Med. ParasitoL, 1999 Apr; 93(3): 225-230). In recent years drug resistant malaria has become one of the most serious problems in malaria control. Drug resistance necessitates the use of drugs which are more expensive and may have dangerous side effects. To overcome the problems associated with drug resistance, treatments comprising combinations of anti-malarial agents are on the rise. A number of anti-malarial combinations are already known in the malarial chemotherapy. For example, a combination of amodiaquine and tetracycline, a combination of sulfadoxine and pyrimethamine known as fansidar, are known therapies for the treatment of P. falάparum. Also fansimef, a combination of mefloquine with sulfadoxine and pyrimetha min e is used against multidrug resistant strains of P. faldparum.

United States Patent No. 5 998 449 describes a method for the treatment of malaria wherein combination of atovaquone and proguanil is used for the treatment of malaria. In US Patent No. 5 834 505, combination of fenozan with another anti-malarial agent selected from artemisinin, sodium artesunate, chloroquine, mefloquine is described for the prophylactic and curative treatment of malaria.

All the aforementioned anti-malarial combinations reported heretofore are generally used for the treatment of P. faldparum. None of the standard anti-malarial combination treatment regimens have been found to be favourable for the treatment of P. vivax malaria which is the most relapsing type of malaria. For a very long time chloroquine was used for the treatment of infections caused by P. vivax, however, chloroquine eradicates only the asexual erythrocytic stages of P. vivax and does not eliminate the hypnozoites. Until recently primaquine has been the drug of choice for the treatment of malarial relapse. Generally the standard therapy for the P. vivax malarial infection comprises of a sequential chloroquine-primaquine combination treatment regimen wherein primaquine is administered for 14 days following the 3 days course of chloroquine. WHO (World Health Organisation) also recommends a 14 days primaquine treatment for P. vivax malarial infection. A shorter duration of cMoroquine-primaquine treatment regimen was also tried out wherein primaquine was administered only for 5 days following the chloroquine course. However, the outcome of the treatment was not encouraging, since the percentage relapse was more than the standard 14 days primaquine treatment regimen (Trans. R. Soc. Trop. Med. Hyg., 93(6), 641-643). Also primaquine is known to cause hemolytic anemia in persons deficient in the enzyme glucose-6-phosphate dehydrogenase (G6PD) (Pharmacol Rev. 21: 73-103 (1969); Rev. Cubana Med trop, 1997; 49 (2): 136-8 ). Moreover, methemoglobin toxicity is another predictable dose-related adverse effect associated with primaquine. Needless to say that in the case of sequential combination therapy the patient may not complete the course once the symptoms of malaria are diminished, hence this may increase the chances of relapse. Thus, the chloroquine- primaquine treatment regimen is not safe with respect to toxicity of primaquine and has a further limitation from the standpoint of patient compliance due to longer duration of treatment.

Another anti-relapse agent namely tafenoquine is disclosed in United States Patent 4 617 394. Though more effective than primaquine, the drug was found to cause methemoglobin toxicity almost three times more than that of primaqu ie (Fundam. Appl. Toxicol. 1988, 10(2), 270-275), hence has drawbacks in terms of safety.

The compound, 3-[l-[[4-[(6-nιethoxy-8-quinolinyl)aιnino]pentyl)am.ino]- ethylidene]-dihydro-2(3H)furanone is a derivative of primaquine. It was described in Indian Patent Specification No. 158111 as 6-methoxy-8-(4-

N-(3′-aceto-4^5′-dihydro-2-furanylamino)- l-methylbutylamino)quinoline , the structure of which was revised to that represented by the following formula I. As per the revised structure, the compound is named 3-[l-[[4-

[(6-metJhoxy-8-quinolmyl)amino]pentyl]amino]ethylidene]-dihydro-2(3H)- furanone (hereinafter referred to as compound I). The revised structure is described in WHO Drug Information Vol. 13, No. 4, pg. 268 (1999).

The compound of formula (I) has been found to be safer and less toxic than the parent compound primaquine (Am. J. Trop. Med. Hyg, 1989 Dec; 41(6): 635-637). Its anti-relapse activity has been found to be comparable to primaquine.

Over the years primaquine was the only drug used for the radical cure of malaria caused by P. vivax. Primaquine is associated with a number of severe adverse effects, therefore there is a need to develop agents which are more effective and/ or less toxic than primaquine. The compound I has been found to exhibit anti-relapse activity comparable to Primaquine (Am. J. Trop. Med. Hyg., 41(6): 633-637 (1989)). However, this compound has been shown to cause less methemoglobin formation (Am. J. Trop Hyg., 41(6): 638-642 (1989) ) and also has less effect on anti-oxidant defence enzymes than primaquine (Biochem Pharmacol. 46(10): 1859- 1860 (1993) ). Thus, this primaquine derivative (I) is found to be less toxic as compared to the parent drug, primaquine.

Therefore, there is a longfelt need for a more practical, effective, patient compliant and safe remedy for the radical cure of P. vivax malarial infection.

The inventors have found that the longfelt need may be fulfilled by providing a treatment regimen consisting of regulated use of chloroquine and 3-[l-[[4-[(6-methoxy-8-quinolinyl)aιnino]pentyl]amino]ethylidene]- dihydro-2(3H)furanone of formula I over a period of between 5 to 8 days.

It has also been found that the treatment regimen may be executed most effectively and in a user friendly manner by providing a combination kit which comprises two anti-malarial agents, namely chloroquine and 3-[l- [[4-[(6-meth.oxy-8-qumolmyl)am^

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The title enamine derivative is prepared by condensation of primaquine (I) with acetyl butyrolactone (II) by means of piperidine.

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http://www.google.com/patents/EP1055427B1?cl=en

• manufacture fo a medicament for the treatment of malaria of primaquine derivative N¹-(3-ethylidinotetrahydrofuran-2-one)-N⁴-(6-methoxy-8-quinolinyl)-1,4-pentanediamine as a gametocytocidal agent. More particularly, this invention relates to the use of primaquine derivative N¹- (3-ethylidinotetrahydrofuran-2-one)-N⁴- (6-methoxy-8-quinolinyl)-1,4-pentanediamine of formula 1 shown below useful for controlling the spread of malaria by virtue of its high therapeutic value as a gametocytocidal agent.

• The primaquine derivative of the present invention does not damage either normal or G-6PD deficient erythrocytes to the extent it is observed with the use of primaquine.
  • scheme:

The following example illustrates the details of the process of this invention:

N¹- (3-ethylidinotetrahydrofuran-2-one)-N⁴- (6-methoxy-8-quinolinyl)-1,4-pentanediamine

• A mixture of primaquine base (0.97g, 3.7 mmole) freshly distilled 3-acetyl-r-butyrolactone (1.0g, 7.8 mmole) and a base like piperidine (2-3 drops) were stirred under magnetic stirrer at room temperature. In an hour or so the reaction mixture solidified. The product was titrated in ether and filtered to get the product. It was crystallised from alcoholic solvent like propanol. Yield 0.89g, m.p. 118-120°C.

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