Broken cellular mechanism of microwave extraction of natural products Application
Emblem wave breaking crest cell technology is the wave heating plug on the selectivity and efficiency instantaneous . Biological material by a suitable treatment emblem wave breaking the cells, a cell disruption means . Practice shows that this technique is especially suitable for intracellular small molecule product extraction, extraction and isolation of natural products in which he has broad application prospects .
Nature rich biological resources to provide mankind with tens of thousands of natural products , which are drugs, spices, food additives and other important sources of fine chemicals . Development and application of natural products , you first need to extract it from the living body . Extraction of natural products , the industry is still widely used conventional leaching operation , time-consuming , inefficient , backward technology .
On the one hand , leaching operation carried out before the extraction without cell disruption , cell wall and / or cell extract a great deal of resistance to extraction for a long time ; addition , leaching operation can not make rapid intracellular inactivation of enzymes , but due to the slow warming promotes the degradation product of the target enzyme , precious material resources are not fully utilized. Therefore, the extraction time is long and low yield is bothering intracellular extraction of natural products is one of the key issues . Currently, people are actively engaged in the extraction of natural products research new technologies , such as supercritical fluid extraction , ultrasonic extraction , microwave enhanced extraction .
From the kinetic point of view, the cell wall and / or the membrane permeability is to limit the rate of extraction of natural products key factor , the cell disruption , will greatly accelerate the extraction of natural products . Existing high pressure homogenizer such as a bead mill , and cell disruption methods can achieve rapid release of the target product , but at the same time releasing the target product , along with intracellular enzymes are released . After release of hydrolytic enzymes and meet the target product , causing loss of the target product . And extracts contain a lot of protein and other impurities , increased the burden of subsequent purification . Therefore, the cell disruption methods are not suitable for extraction of natural products . Therefore, the study of small biomolecules specifically for cell disruption method of extraction , the research and development of natural products of great significance . We focused on natural products generally good thermal stability characteristics of the microwave technology for cell disruption , the establishment of a suitable biological intracellular small molecules extracted cell disruption techniques - Microwave broken cells.
Microwave broken cells is based on the selective microwave heating , instantaneous and efficient , controlled microwave conditions suitable to achieve. Microwave broken cells were extracted by reducing the resistance , the intracellular dissolution of small molecules become very easy , can greatly shorten the extraction time . In addition , the microwave treatment is also the target of intracellular hydrolytic enzyme inactivation , the extraction process to prevent degradation of the desired product . Therefore , we propose a "Microwave Cell Disruption " concept, and the successful conduct of the yeast intracellular trehalose and medicinal plant Rhodiola Rhodiola into callus extract . Firstly, in order to clarify the yeast cells as an example the mechanism of microwave cell disruption , and then break through examples comparing the microwave cell extraction technology superiority.
Is a frequency of the microwave to 30 00GHz 30 00MHz high frequency electromagnetic wave , which has an electromagnetic wave such as reflection, transmission and interference , diffraction , polarization, and the energy associated with electromagnetic wave transmission properties , and can be used heated by microwave the microwave field in the polar molecules or fast swing dipoles produce similar effects of friction energy is obtained , to dielectric heating . Microwave heating has good selectivity, different materials due to their different dielectric properties , heat in the microwave field characteristics are very different. Other ions in water and microwave can be rapidly heated , and glass , polytetrafluoroethylene is microwave transparent , does not absorb microwave energy, which can be microwave heating . In addition, the rapid and efficient microwave heating , easy to implement continuous and automatic . Given these characteristics of microwave technology , microwave food drying , sterilization, and other fields has been widely expanded industrial applications .
Drunk mother bacteria with typical cell structure, the cell wall , cell membrane, nucleus, vacuole , mitochondria and cytosol , and the like . Yeast cell protoplasm containing one or more sizes vacuole , vacuole diameter . ..-u33m. cells in the stationary growth phase is particularly evident , often the largest organelle . When cells begin sprouting in nutrient medium , the large vacuole is extruded into two small vacuoles , bud formation , the bubble is assigned to the parent cell and daughter cells . After emergence , the small vacuoles or fusion recombined to form a large vacuole . Principle known by the microwave heating , the positive and negative ions , and water and other polar substances in the microwave absorption capacity is relatively strong , non-polar material hardly absorbs microwaves. Since yeast cells typical cell structure , or different in different parts of the cell organelles , the positive and negative ions and polar substances such as water distribution is uneven , so that when the yeast cells were processed in the microwave field , the yeast cells will be localized heating .
Yeast cells localized heating in the microwave field is physically broken microwave yeast cells Kui basis . Enriched yeast vacuole free water inside the cells of the site, when the yeast cells to microwave radiation , free water absorbs microwave energy , the rapid heating , the temperature reaches the boiling point and vaporization , so the intracellular pressure. Yeast cell wall and cell membrane can withstand the internal pressure is limited, when the microwave heating caused by the intracellular cell can withstand pressures up to the limit , the yeast cells will be bursting the cells were fractured .
After breaking through on the microwave scanning electron microscope found in yeast , yeast cells generally occurs first in the microwave broken cell budding site . The author explains this phenomenon as follows : For a cell with buds , the mother cells and daughter cells each contain their own vacuole , so when receiving the yeast treatment in the microwave field , its precursor and heat generation are subject to internal pressure shoots , and thus the two cells a reverse force . Makes the bud from the mother cell rupture in its budding site : For in G, phase of the cell , intracellular parties inward pressure equal, but as the cell wall at the bud scars suffered damage to one of the site , but also easily lead to stress concentration, so cells in the bud scar at break open .
Yeast cells under the effect of the microwave field , the first part of the budding burst , then, if it continues to be microwave radiation , the cells will heat dehydration , is quickly dried. Accordingly , other parts of the cell wall , cracks appear . In summary , the microwave has broken cells is the result of two mechanisms . The first is local heating causes the cell pressure within the cell wall and membrane first in their most vulnerable parts of the rupture ; then . Cell dehydration , the surface cracking. The microwave treatment time from different yeast cells SEM image can be clearly observed in yeast cells broken microwave two different phases .
In budding yeast phase (B) without buds drunk mother figure 1, the yeast cells more microwave crushing mechanism shown in Figure 3 . Tender wave breaking cell technology in the extraction of natural products application is composed of two glucose molecules trehalose combination of non-reducing double lining . Widespread in living organisms that cryptic dehydration plants and animals , well confer such species to withstand high temperatures , drought , dehydration and other adverse environmental stress capability. In addition , seaweed Boring kept in dry conditions with proteins, nucleic acids and other macromolecules from damage the structure and function of the specific effects. Therefore, as a protective agent activity of biological products and food additives , trehalose in proteins , enzymes , vaccines, vaccine, genetic engineering drugs and food , the production of cosmetics and has broad application prospects. Saccharomyces cerevisiae , especially baker's yeast intracellular trehalose content Feng livestock as an important source of commercially available products trehalose . Since trehalose hydrolase enzyme with an algae pond algae Boring coexist in drunk mother cell. Therefore, in order to prevent the degradation of seaweed essence , drunk mother intracellular trehalose extraction , mostly high concentration of alcohol as solvent, at the boiling point temperature. The broken cells using microwave extraction technology, with water as solvent , at room temperature 10 minutes to complete extraction operation , and high trehalose yield than traditional extraction plus % . In addition , compared with the traditional process , microwave extraction of broken cells , proteins and other macromolecules less elution of impurities , thereby reducing the burden of separating the target product follow .
Products active protection agents and food additives , trehalose in proteins , enzymes , vaccines, vaccine, genetic engineering drugs and food , the production of cosmetics and has broad application prospects. Saccharomyces cerevisiae , especially baker's yeast intracellular trehalose content Feng livestock as an important source of commercially available products trehalose . Since trehalose hydrolase enzyme with an algae pond algae Boring coexist in drunk mother cell. Therefore, in order to prevent the degradation of seaweed essence , drunk mother intracellular trehalose extraction , mostly high concentration of alcohol as solvent, at the boiling point temperature. The broken cells using microwave extraction technology, with water as solvent , at room temperature 10 minutes to complete extraction operation , and high trehalose yield than traditional extraction plus % . In addition , compared with the traditional process , microwave extraction of broken cells , proteins and other macromolecules less elution of impurities , thereby reducing the burden of separating the target product follow .
These examples show that microwave crushing technology not only theoretically enriched the connotation of cell disruption , but also has high practical value , the technology for biological extraction of intracellular small molecules with a certain degree of universality . Compared with traditional methods , microwave broken cell extract has a lot of advantages , mainly in the extraction time is short, the target product yield , so little elution of impurities . Therefore , the microwave broken cell extract is a time-saving , high efficiency , energy saving, clean and safe natural product extraction technology . As the chemical synthesis of new drug development more difficult, famous foreign pharmaceutical companies and research institutions have to look into the nature , find new drugs from plants . And profound culture of Chinese herbal medicine . Have a good knowledge accumulation, and gradually gained international recognition . We hope to be able to microwave technology process of modernization of traditional Chinese medicine and natural medicine research and development , has played its due role for the medicine to the world can do something.