氯喹曾经是对付疟疾的特效药物，可随着疟原虫的耐药性不断增加，氯喹也被人们日渐忽视。但是新的研究表明，它仍然能够在对付疟疾的战役中发挥重要作用。
通过把氯喹与其它化合物结合在一起，科学家已经让这种药物对甚至对氯喹具有耐药性的疟疾仍然有效。这项由美国波特兰州立大学David Peyton领导的研究发表在8月12日的《药物化学杂志》（Journal of Medical Chemistry）上。
自从上个世纪90年代以来，科学家们已经试验了各种可能抑制耐药疟疾蛋白的化合物。Peyton的研究组把一种“逆转剂”（reversal agents）附着在氯喹分子上，使之产生一种单一混合物分子。随后，Peyton等人测试了这种分子在实验室中对恶性疟原虫（Plasmodium falciparum）的有效性。
让人鼓舞的情况出现了。这种“逆转性氯喹”对于耐氯喹的疟原虫的效果，至少与氯喹对付不具有氯喹耐性的疟原虫的效果一样。在被夏氏疟原虫(Plasmodium chabaudi)感染的老鼠身上，这种药物也表现出同样的效果。夏氏疟原虫在啮齿动物身上引发疟疾。这种药物没有明显的副作用。
Peyton指出，尽管好几种化合物都发挥了逆转剂的作用，它们所需的剂量通过都比逆转性氯喹高。目前，Peyton的研究组正在开发质量更好的相关分子。
英国伦敦圣乔治医院医学院寄生虫病教授Sanjeev Krishna表示，对付耐药性疟疾的各种手段都应该尝试。但是他指出，一种富有希望的化合物是否会进入药物开发阶段，这要依靠各种因素，诸如成本，生产的容易程度以及服用该化合物后它如何发挥作用。
英文原文：
Hybrid molecule could treat drug resistant malaria
A drug that was one of the main tools for treating malaria until the parasite grew resistant to it could still have a major role in fighting the disease.
Researchers have made the drug — chloroquine — effective against even chloroquine-resistant malaria by binding it with another chemical. The research, led by David Peyton of Portland State University, United States, was published on 12 August in the Journal of Medical Chemistry.
Since the 1990s, researchers have been experimenting with chemicals that seem to block the malarial proteins that confer drug resistance.
Peyton's team attached one of these 'reversal agents' to chloroquine to produce a single hybrid molecule. They then tested its effectiveness against the malaria parasite Plasmodium falciparum in the laboratory.
The 'reversed chloroquine' was at least as effective against chloroquine-resistant parasites as chloroquine is against non-resistant malaria.
The drug was also effective in mice infected with Plasmodium chabaudi, which causes malaria in rodents. There were no obvious side effects.
Peyton said that, although several chemicals act as reversal agents, the doses needed are generally higher than with reversed chloroquine. His team is currently developing related molecules with improved qualities.
Sanjeev Krishna, a professor of parasitology at St. George's Hospital Medical School in London, United Kingdom, says that different approaches to the problem of drug-resistant malaria are always welcome.
But he points out that whether a promising compound enters drug development would depend on factors such as the cost and ease of producing it, and how the chemical acts when taken.
