Mankind has long known about the healing properties of medicinal plants produce a variety of medicinal compounds. Now MIT chemists have discovered a new way to increase the possibility of pharmaceutical plants, making them genetically to produce unnatural variants of their usual products.
Researchers led by Professor Sarah O’Connor added bacterial genes to the plant Vinca to attach such halogens, such as chlorine or bromine, a class of compounds called alkaloids plant which produces naturally. Many alkaloids possess pharmaceutical properties, and halogens, which are often added to antibiotics and other drugs, can make more effective drugs, or persist longer in the body.
The primary purpose of alkaloid vinblastine named (vinblastine), commonly used in the treatment of this form of cancer as Hodgkin (Hodgkin’s lymphoma). Professor O’Connor sees vinblastine and other drugs made by plants as a "timber" that it can be modified using a variety of methods, improving their efficiency.
"We’re trying to use plant biosynthetic mechanisms to easily create an entire range of natural products," - she said. "If you often experience the structure of natural products, you get a different or improved biological and pharmacological activity."
Applied new genes to the plants was practiced before: In the 1990s, scientists developed corn that could produce an insecticide called Bt, which comes from a bacterial gene. Nevertheless, the method O’Connor known as metabolic engineering exceeds a method of adding a gene which encodes for a novel protein. Metabolic Engineering operate on a series of reactions which main organisms used for the construction of new molecules, genes for adding new enzyme, which in turn reduced form of these synthetic pathways. This can lead to a huge number of final results.
In previous experiments, O’Connor and her students generated by the root cells of periwinkle to create new components, feeding them a slightly modified version of their usual starting materials. The new study, cells are created in order to identify genes which are encoded for enzymes that connect chloro or bromo to other precursors and alkaloids vinblastine.
Two new genes were extracted from bacteria which naturally produce halogenated compounds, since such compounds generate a naturally rare plant. It is also possible, but it is very difficult to synthesize halogenated alkaloids in a laboratory.
To create alkaloids, plants first convert tryptophan into tryptamine aminakislotu. After this first step, it takes about a dozen responses, so that plants can produce hundreds of other end products. In the new genetically engineered plants, a bacterial enzyme called halogenase attaches a chlorine (or bromine) to tryptamine. This halogen molecule remains during the entire process of synthesis. In future work, the researchers hope to create a whole periwinkle plants to produce new compounds. They also work to improve the production of synthesis, which is almost 15 times lower than the natural alkaloid production in plants.
Original: Sciencedaily Translation: M. Potter