Patent Publication Number: US-5024731-A

Title: Method of manufacturing material for medical and pharmaceutical products from pyroligneous acid

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a method of manufacturing a material for medical and pharmaceutical products from pyroligneous acid (or wood vinegar). 
     2. Description of the Prior Art 
     Pyroligneous acid is extracted as water content in smoke produced by heating trees and/or the bark thereof. 
     Such pyroligneous acid is extracted as by-product in the manufacture of charcoal, and usually it is discarded. Recently, researches and investigations concerning the utility of pyroligneous acid have been conducted, and methods for extracting pyroligneous acid have been developed. 
     However, no substantial utility effects of pyroligneous acid are obtained, and at present pyroligneous acid is finding insufficient applications. 
     It is recently recognized that pyroligneous acid is greatly effective as medicines. However, it has not yet been utilized for medicines. 
     SUMMARY OF THE INVENTION 
     The inventors conducted researches and investigations concerning the effects of pyroligneous acid as medicine and developed a method of obtaining a material for medical and pharmaceutical products from pyroligneous acid by removing noxious components thereof. 
     The present invention seeks to obtain a material for medical and pharmaceutical products from pyroligneous acid. 
     The inventors heated pyroligneous acid and found that the temperature thereof is elevated quickly up to 98° C., then slowly elevated up to 103° C. and then elevated quickly again, a three-step rise of temperature. The inventors extracted evaporation gas with a temperature range lower than 98° C. as first step, a range between 98°˜103° C. as second step and a range higher than 103° C. as third step, liquified the extracted gas by cooling and examined the composition of the extract in the individual steps. 
     Liquid obtained by extraction in the first step greatly contained noxious components such as formaldehyde and methanol. Liquid obtained by extraction in the third step contained such noxious components as 3,4-benzpyrene. In contrast, liquid obtained by extraction in the second step did not contain the noxious components as in the liquids obtained by extraction in the first and third step. Animal experiments were conducted using the liquid obtained by extraction in the second step (extract) to find that the liquid had medical effects particularly on liver diseases and diabetes as in animal experiment results. 
     ANIMAL EXPERIMENT RESULTS 
     A. Effect of Administration of Extract on Therapy of Acute Hepatitis Due to Galactosamine 
     Animal Used 
     Rat 
     Method of Experiment 
     To rats was administrated galactosamine to induce acute hepatitis, and the extract was administrated twice a day to biochemically study the crisis suppression effect of the extract on acute hepatitis. 
     Measurement Items 
     Measurements of total bilirubin, glucose and GOT 
     Measurements 
     
         ______________________________________                                    
           T. Bilirubin                                                   
                    Glucose                                               
           (mg/dl)  (mg/dl)  GOT (K.U.)                                   
______________________________________                                    
Before administration                                                     
             0.36       95        111                                     
1st day                                                                   
Experiment Group                                                          
             0.56       122      1229                                     
Contrast Group                                                            
             0.83       111      1576                                     
2nd day                                                                   
Experiment Group                                                          
             3.12       95       3056                                     
Contrast Group                                                            
             4.91       62       3777                                     
3rd day                                                                   
Experiment Group                                                          
             2.99       106      1099                                     
Contrast Group                                                            
             5.14       75       1711                                     
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     Result 
     When galactosamine was administrated to the rats, the GOT quickly increased in a period from 6 to 48 hours from the administration, and most rats dead in a week. With rats, to which the extract was administrated, the GOT increased but at a lower rate of increase compared to the contrast group rats. In addition, quick recovery was observed, and no rat dead. 
     B. Effect of Extract Administration on Alloxan Diabetes 
     Animal Used 
     Rat 
     Method of Experiment 
     45 mg/kg of alloxan was given venous administration to rats to induce alloxan diabetes, and the extract was given by adding it by 1% to drinking water for free drinking. Glucose was measured at time intervals. 
     Measurements 
     
         ______________________________________                                    
               Glucose (mg/dl)                                            
______________________________________                                    
Before administration                                                     
                  95                                                      
1st week                                                                  
Experiment Group 348                                                      
Contrast Group   383                                                      
2nd week                                                                  
Experiment Group 336                                                      
Contrast Group   395                                                      
3rd week                                                                  
Experiment Group 195                                                      
Contrast Group   322                                                      
______________________________________                                    
 
    
     Result 
     By giving alloxane by venous administration to the rats, the glucose value which was about 100 mg/dl was increased to 350 to 400 mg/dl in two days, and the symptom of diabetes was shown. With the experiment rats, to which the extract was given as 1% content in drinking water, the glucose value was the same as that in the contrast group rats up to 14 days from the start of experiment, but it turned to be reduced gradually from the 15th day and was reduced to about 200 mg/dl in the 25th day, indicating an effect of the extract to improve the rise of the glucose value in the diabetes. 
     According to the present invention, the extract is obtained by heating pyroligneous acid, extracting the resultant evaporation gas in a temperature range of 98° to 103° C. and liquifying the extracted gas by cooling. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now, an embodiment of the present invention will be described in detail. 
     The kinds of trees as material of pyroligneous acid used according to the present invention and method of extraction of pyroligneous acid from trees or the like are by no means limitative. 
     In this embodiment, pyroligneous acid is extracted from arber and bark or oak, shinquapin, cherry, beech, etc. In the method of extraction, the trees noted above are carbonated at a temperature of 170° to 800° C., and smoke generated by this carbonization and containing water is led to be cooled down, thereby liquifying water content contained in the smoke for extraction. 
     From pyroligneous acid thus extracted, tar and solid impurities are separated by precitation by leading the acid for a couple of months or subjecting the acid to centrifugal separation. The supernatant liquid is taken out for use. 
     The supernatant liquid was heated by using a mantle heater, evaporation was from the supernatant liquid was discharged until a temperature of 98° C. is reached by the liquid, and evaporation gas generated while the supernatant liquid is being elevated in temperature from 98° to 103° C., i.e., evaporation gas in a temperature range of 98° to 103° C., is extracted, and the extracted gas is liquified by cooling. 
     The liquid thus obtained can be a material for medical and pharmaceutical products. 
     In the above method, the evaporation gas is not extracted but discharged until reaching of 98° C. by the pyroligneous acid supernatant liquid. Thus, noxious components contained in the evaporation gas can be removed. In addition, the extraction is stopped when the supernatant liquid temperature exceeds 103° C. Thus, the extract is free from noxious components contained in subsequently generated evaporation gas. It is thus possible to obtain a material for medical and pharmaceutical products, which is free from noxious components. 
     As has been shown, according to the present invention pyroligneous acid is heated, and evaporation gas in a temperature range of 98° to 103° C. is extracted and liquified by cooling, permitting a material for medical and pharmaceutical products free from noxious components to be obtained, which greatly contributes to the therapy of diseases. Further, since the method of manufacture is simple, the material can be obtained readily and at low cost. Further, the present invention greatly contributes to the utility of pyroligneous acid which has not heretofore been finding sufficient applications.