商品描述

Chitosan: Where did it come from?

Regardless of chitosan's miraculous overview, it is a very simple substance which has been around for ages.  It is taken from chitin, a polysaccharide found in the exoskeletons of crustaceans.  It is processed by removing the shells from shellfish such as shrimp, lobster, and crabs.  The shells are then ground into a pulverous powder.  This powder is then deacetylated, or basically stripped of specific chemical groups which allows the compound to thus actively "soak up fats."  Or so this is what the producers claim.  It has been used in the past in the process of detoxifying water.  It was simply spread over the surface of water, where it would immediately absorb any toxic substances such as greases, oils, or dangerous heavy metals.  The process is so complete that a scum forms over the surface of water and is then easily removed.  For this reason, chitosan is extremely popular all over the world in water purification plants.  The present form of chitosan has just been introduced recently as a weight loss supplement.

How It Works:

ITOSAN DERIVATIVES AND METHODS OF MANUFACTURING THE SAME The present invention relates to chitosan derivatives having good physiological and biocompatibility with medical safety as well as high water- solubility and relates also to a method of manufacturing such chitosan derivatives. Further, chitosan is substantially insoluble in organic solvents. For this reason, industrial application of chitosan has been limited.

Let's now take a look at exactly what is chitosan and how it is used for weight loss.  The allegations of how chitosan works are as follows.  However, note that there is no significant studies to thus back up this information or to explain exactly how such procedures take place. Basically stated, chitosan is a special fiber which is able to "soak up" or absorb anywhere from six to ten times its weight in fat and oils.  In substance, it is chemically similar to the plant fiber, cellulose. However, chitosan is able to significantly bind with fat molecules and convert them into a form which the human body does not absorb. (Revolutionary Discovery: Chitosan)  It claims to affect the fat prior to it reaching the stomach and thus the fat never has a chance to be metabolized.  It prevents the absorption and storage of fat by converting into a gel which "traps" the fat.  In some sort, it creates a "grease ball" from this excess fat, which is too large to be absorbed by the body.  It thus becomes an inert substance and is excreted in the stool. (Absorption of Fats)  Chitosan fiber is unlike other fibers in that it carries a positive ionic charge.  Since lipids, fats, and bile acids all possess negative charges, there is a chemical bond between the two and thus they attract naturally to one another. (Fat Magnet)  This unique ability is what makes chitosan so remarkable.  This amazingly "too good to be true" ability is also what causes suspicions to arise on the validity of these claims.

Benefiting Weight Loss:

Besides from the obvious effect that fat is not absorbed into the body with the presence of chitosan, it goes a lot deeper in benefiting weight loss.  Chitosan is a 100% natural and acts as a super fiber. Thus, supplementing the diet with chitosan, is part of creating a cleansing process which is said to be extremely vital to weight loss. Take note that these are again the simple declarations made by the producers of chitosan and are supported with no background studies or thus medical proof of any sort.  Another stated advantage of chitosan comes from the idea that the chitosan-bound fat leaves the intestinal tract without ever entering the bloodstream.  Exactly how this process takes place is not clear and seems to be somewhat far fetched.  If this indeed is possible, then the point is made that there would be no caloric value and no matter how much chitosan a person takes, the caloric count remains zero. (Revolutionary Discovery: Chitosan)  The producers of chitosan-based products also try to claim that since a person taking chitosan continues to eat some sort of fats and is able to continue eating these types of food, the body does not crave such fattening foods nor is it starving or feeling any added sense of hunger.  By supplementing chitosan into one's diet, there is less fat that the body accumulates.  With less fat entering the body, the body turns to previously stored body fat to burn up.  This shifts the energy source from diet to stored body fat and results in a net reduction in that fat - and in weight. (Fat Zapper)   Obviously, the allegations are extremely pleasing, now whether or not they actually could be a reality is another side to these claims.

Claims:

l Reduces fat absorption

l Lowers cholesterol levels

l Promotes weight loss

DESCRIPTION:

Chitosan is a copolymer of glucosamine and N-acetylated glucosamine. Its polycationic nature is unique among polysaccharides, and it confers to it diverse biological properties such as antimicrobial activity, elicitation of plant defense reactions, wound-healing property, and cholesterol-lowering effect. The effectiveness of chitosan appears to be dependent on its molecular weight in various applications. Development of an efficient process for reduction in molecular size of chitosan without altering its chemical structure is desirable.

The objective was to investigate the possibility of fragmentation of chitosan in an aqueous solution by microfluidization and to evaluate molecular weight, molecular weight distribution, and the structure of the resultant fragments.

Microfluidization was performed under different conditions of interaction chamber pressure and number of passes. The effect of concentration and initial molecular weight of chitosan was also examined. Degree of fragmentation was followed by viscometry and size-exclusion chromatography. The chemical structure of chitosan and its fragments was examined by elemental analysis and 1H NMR spectroscopy.

The effect of interaction chamber pressure on chain scission was linear and appears to be the dominant factor, more than the number of passes in the fragmentation process. Chain scission increased with an increase in initial molecular weight of chitosan and a decrease in chitosan concentration. Molecular weight distribution of the fragments was narrower than that of the original polymer. The degree of acetylation of fragments increased in 0.1 M CH3COOH as the aqueous solvent but not in 0.04 M HCl.

The results suggest that at any given pressure, the molecular weight of chitosan reaches a limiting value beyond which no degradation occurs, and that larger macromolecules were more susceptible to fragmentation. This method is useful for reduction of solution viscosity and partial degradation of high polymer.

Chitosan and chitin are polysaccharide polymers containing more than 5,000 glucosamine and acetylglucosamine units, respectively, and their molecular weights are over one million Daltons. Chitin is found in fungi, arthropods and marine invertebrates. Commercially, chitin is derived from the exoskeletons of crustaceans (shrimp, crab and other shellfish). Chitosan is obtained from chitin by a deacetylation process.

Chitin, the polysaccharide polymer from which chitosan is derived, is a cellulose-like polymer consisting mainly of unbranched chains of N-acetyl-D-glucosamine. Deacetylated chitin, or chitosan, is comprised of chains of D-glucosamine. When ingested, chitosan can be considered a dietary fiber. Chitosan has the following chemical structure:

Chitosan itself is the major source of the nutritional supplement glucosamine.

Chitin is the prominent structural polysaccharaide in the exoskelton of insects, crustaceans and invertebrates in general. The shells of crabs and lobsters are common sources of chitin. In many respects chitin plays an analogous role to collagen in the higher animals and cellulose in terrestrial plants. It is assumed that chitin is even more widespread and abundant in nature than cellulose. However, its utilization is very difficult because of its insolubility in water and many commercial solvents.

On the other hand, chitosan, N-deacetylated chitin, is soluble in various acidic solvents and also has a remarkable ability to form specific complexes with a number of ions including transition and post-transition metal ions. Therefore, chitosan has received much attention as a functional biopolymer for diverse applications. These functions undoubtedly depend on not only the chemical structure but also the molecular conformation of chitosan, its interactions with guest molecules and the resulting packing arrangements. Therefore, structural studies on these polymers are important for better understanding of their functions, for their utilization and also for improvement of their functional properties.

So far we have succeeded in the structure analyses of hydrated and anhydrous chitosan. Now we are analyzing chitosan complexes with various acids and metal ions.

Chemical Name:  Poly-(1-4)-2-Amino-2-deoxy-ß-D-Glucan

Structure:

Chemical Name:  Poly-(1-4)-2-Amino-2-deoxy-ß-D-Glucan

Structure:

Molecular Formula & Weight：

Chitosan, unsolved in water but tenuous acid and absorbed in body is abstracted from Chitin. As the first derivation, with chemical structure of alkyl polysaccharide polymer with cation, it has peculiar physical & chemical capability and biological activating function.

Chitosan is a linear polysaccharide composed of randomly distributed ß-(1-4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit). Chitosan is produced commercially by deacetylation of chitin (can be produced from chitin also), which is the structural element in the exoskeleton of crustaceans (crabs, shrimp, etc.). The degree of deacetylation (%DA) can be determined by NMR spectroscopy, and the %DA in commercial chitosans is in the range 60-100 %. The amino group in chitosan has a pKa value of ~6.5, thus, chitosan is positively charged and soluble in acidic to neutral solution with a charge density dependent on pH and the %DA-value. In other words, chitosan is bioadhesive and readily binds to negatively charged surfaces such as mucosal membranes. Chitosan enhance the transport of polar drugs across epithelial surfaces, and is biocompatible and biodegradable. Purified qualities of chitosans are available for biomedical applications. Chitosan and its derivatives such as trimethylchitosan (where the amino group has been trimethylated) have been used in non-viral gene delivery. Trimethylchitosan, or quaternised chitosan, has been shown to transfect breast cancer cells . As the degree of trimethylation increases the cytotoxicity of the derivative increases . At approximately 50% trimethylation the derivative is the most efficient at gene delivery . Oligomeric derivatives (3-6 kDa) are relatively non-toxic and have good gene delivery properties.

Chitosan is frequently sold in tablet form at health stores as a 'fat attractor': It is supposed to have the capability of attracting fat from the digestive system and expelling it from the body so that users can, it is claimed, lose weight without eating less. However, scientific research suggests that these claims are entirely without substance. In fact, using chitosan can have the deleterious effect of rendering ineffective certain minerals found in foodstuffs and required by the body in order to remain healthy.

MECHANISM OF ACTION:

Chitosan is, at the pH of the gastrointestinal tract, a positively charged polymer and can bind to negatively charged substances. It is believed that chitosan, similar to cholestryamine, has bile acid sequestration activity and that this may be the mechanism for its hypocholesterolemic effect. There is some evidence that chitosan binds to bile acids and some evidence that the polymer affects the metabolism of intestinal bile acids. However, in contrast to cholestyramine, chitosan does not have consistent hypocholesterolemic activity. There is also evidence that chitosan binds to fats in the intestine, blocking their absorption.

The mechanism of action of chitosan's possible beneficial effects on renal disease in some is unknown. Chitosan can absorb urea and ammonia, but it is unclear whether this mechanism has anything to do with its putative renal effects.

Figure 1 shows the DSC thermograms of pristine chitosan membrane and CSCM samples. A broad endothermic peak was observed for all testing samples. As the silica contents in CSCM samples increased, the peak shifted to lower temperature region and the endothermic enthalpy decreased. This endothermic peak might result from the removal of the adsorbed water in the chitosan membranes under heating. Results from thermogravimetric analysis on the samples supported the above-mentioned inference (Figure 2). A weight loss before 200 C was observed for all samples. This weight loss was considered to be corresponding to the absorbed water in the membranes. The amounts of weight loss at this temperature range decreased with increasing silica contents of the CSCM samples. This implies that the formation of a chitosan-silica complex would decrease the water adsorbability of chitosan membranes, i.e., decrease the hydrophilicity of the membranes. The hydrophilicity of the membranes was then estimated by measuring their surface contact angles with water. The addition of 5 phr ST-GPE-S into chitosan dramatically increased its contact angle from 79 to 94 . The contact angles of CSCM with water continuously increased with increasing ST-GPE-S contents, indicating that CSCMs were less hydrophilic than the pristine chitosan membrane.

Figure 6 DSC thermograms of pristine chitosan (CSCM-0) and chitosan-silica complex membranes.

Figure 7 TGA thermograms in air: pristine chitosan (CSCM-0) and chitosan-silica complex membranes.

Thermal stability of CSCM samples could be referred from their TGA thermograms (Figure 2). A rapid weight loss around 260 C resulted from the chitosan chain degradation, whereas the second rapid weight loss derived from the oxidative degradation of char formed from the chitosan chain degradation. After the addition of ST-GPE-S, an enhancement on thermal stability and a retardation on the oxidative degradation were observed for these CSCM samples. High ST-GPE-S contents of the CSCM membranes resulted in high char yields at 800 C. It is noteworthy that the values of char yields were almost coincident with the amounts of the ST-GPE-S additives. Therefore, the increased char ratios mainly resulted from the nonvolatile silica, and the addition of ST-GPE-S did not enhance char formation from the organic part (chitosan) of the complex membranes. Similar results were also reported for other polymer-silica hybrid materials and nanocomposites. On the basis of the above, one could conclude that silica in chitosan might not alter the thermal degradation mechanism of chitosan.

RESEARCH SUMMARY:

There are several studies, in both animals and humans, demonstrating chitosan's effect on lipids. These effects have generally been more dramatic in various animal models, possibly due to higher chitosan intake in many of those studies. Some of these animal studies show very dramatic reductions in cholesterol and in LDL-cholesterol. Some have observed increases in the HDL-cholesterol, as well.

In humans, results have been less clear-cut, though still suggestive of positive effects. In one recent placebo-controlled, double-blind study, there was a significant decrease in LDL-cholesterol among subjects receiving 2,400 milligrams of chitosan daily, compared with placebo subjects. Chitosan had no significant effect on serum total cholesterol or on HDL-cholesterol, but it slightly increased triglycerides. Others have reported similar effects: reduced LDL-cholesterol with little or no effect on HDL and total cholesterols. A few others, however, have reported no lipid effects. Differences may be due to dissimilar dosing.

In animal models of chronic renal failure, chitosan produced decreases in serum urea nitrogen, serum creatine and serum phosphate. It also ameliorated anemia and increased fecal weight, fecal water content, fecal nitrogen and fecal sodium. The apparent protein ratio was decreased in a dose-dependent pattern in some of these studies, and survival times were markedly and significantly extended.

In a human study of 80 patients with chronic renal failure, similarly encouraging results were obtained. Half of these patients received 30 chitosan tablets (each containing 45 milligrams of chitosan) three times a day for a total of 4,050 milligrams daily. After four weeks on this regiment, these subjects experienced significant reductions in urea and creatine levels in serum, compared with controls. Significant gains were also measured in physical strength, appetite and sleep patterns after 12 weeks of chitosan supplementation. It is interesting to note that chitosan at this dose also significantly reduced total serum cholesterol levels (and increased serum hemoglobin levels).

Favorable lipid results would suggest that supplemental chitosan might help prevent atherosclerosis. This idea has been tested in some animal models with promising results. Using the apolipoprotein E-deficient mouse model of atherosclerosis, for example, researchers recently showed that a 5% chitosan diet could produce "a highly significant inhibition of atherogenesis"--42% inhibition in the whole aorta and 50% inhibition in the aortic arch, compared with controls. These positive effects were attributed to a 65% reduction in blood cholesterol levels (after 20 weeks on the 5% chitosan diet).

Some research has demonstrated that topical preparations containing chitosan can help speed wound healing. Other preliminary studies suggest that chitosan might be useful in lean type non-insulin-dependent diabetes mellitus. In an animal model of this disease, chitosan significantly reduced blood glucose, cholesterol and triglycerides. (The same results, however, could not be obtained in obese type NIDDM.) Still other similarly preliminary studies suggest that chitosan might help protect the liver against some toxins. More research in these areas is needed.

Claims have been made that chitosan can help reduce weight. There is insufficient data to support this claim. Two recent studies failed to find any weight-loss effect from the use of chitosan in overweight subjects. In the larger and longer-term of these two studies, 51 healthy obese women were given either placebo or 2,400 milligrams of chitosan for eight weeks. No significant weight reduction was noted in the treatment group.

Similarly, there is insufficient data to support claims that chitosan fights cancer, heals ulcers, aids digestion, or boosts or otherwise modifies immunity.

Chitosan  product:

molecular weight :3000-300,00

Appearance: yellow powder

Assay:99.27%

Moisture:4.52%

Ash:0.91%

As.:5ppm

Heavy Metal:20ppm

Mesh: 80mesh

Total Plate Count:1000cfu/g

Yeast and Mold:100cfu/g

Salmonella: Negative

E.Coli: Negative

Chitosan is used imostly applied in textile, printing, leather, cigarette, plastics, foodstuff,fodder,color film,medicine and paper-manufacturing industry, biological-engineering industry,agriculture-protecting industry,dirty water-cleaning industry,etc.Depending on the different viscosity,in particular,chitosan owing to the characters naturally activating capability without virulent and side effect,absorbed in body,reducing heavy metal,adjusting PH in body,improving the immunity,strongtheming the liver function,ameliorating digestion,abasing fat and sugar, restaining cancer occurring,and expelling heavy metal out of body,is greatly applied as the food protecting health and the medicine additive.