JERUSALEM, Sept. 9 (Xinhua) — Israeli and Italian scientists have developed a method which may lead to cost-lowering and streamlining of drug, pesticide and fertilizer production, the Weizmann Institute of Science (WIS) reported Monday.
In the mid-19th century, Louis Pasteur discovered molecular “handedness,” the existence of left and right handed versions of the same molecule.
He then separated mirror-image crystals manually, and speculated that the differently handed molecules might have been created by Earth's magnetic field.
This assumption was later disproved, but scientists from the WIS, the Hebrew University of Jerusalem and the University of Modena and Reggio Emilia established an indirect link between magnetism and molecular handedness.
In the study, published in the journal Chemical Science, the team also exploited the link to develop an effective method for separating mirror-image crystals.
Sorting crystals by chirality is crucial in the manufacture of drugs, pesticides and numerous other chemicals, because only molecules of a particular chirality produce the desired effect, without harming.
According to the researchers, “existing separation methods need to be tailored individually to each type of crystals. In contrast, our approach can be applied to any chiral molecule that can form a chiral crystal, and is therefore likely to be cheaper and more efficient.”
To sort the crystals, the scientists used the CISS (chirality-induced spin selectivity) phenomena, whereby when chiral molecules interact with a surface, they become polarized according to a magnetic property of their electrons.
Previous studies have found that by using CISS, substances may be sorted according to their directions, and in the new study, the scientists showed that the method may also be applied to crystals that spontaneously form from chiral molecules.
When the team introduced magnetic elements into several solutions, each containing a different amino acid, only molecules of a particular chirality were drawn to the surface.
Once the molecules reached a high concentration, the amino acid began to crystallize. In this manner, the scientists obtained crystals of the amino acid containing molecules of only one chirality without the other.
