| Molecular Formula | C17H35N5O6 |
| Molar Mass | 405.49 |
| Density | 1.0897 (rough estimate) |
| Melting Point | >200° (dec) |
| Boling Point | 526.82°C (rough estimate) |
| pKa | 13.16±0.70(Predicted) |
| Refractive Index | 1.7600 (estimate) |
| Physical and Chemical Properties | Chemical properties white amorphous powder, melting point> 200 ℃ (decomposition). [α]D23 87.5 (C = 0.1, water). Insoluble in water and lower alcohols, insoluble in organic solvents. Fetiamycin Sulfate A(FortmicinASulfate):C17H35N506?2H2SO4. White or yellowish white crystalline powder or lumps, odorless. It is very soluble in water, difficult to dissolve in ethylene glycol, and almost insoluble in methanol, ethanol or ether. Acute toxicity LD50 mice (mg/kg):380 intravenous injection, 400 subcutaneous injection. |
| Use | Uses aminoglycoside antibiotics, broad-spectrum, gram-negative bacteria, such as Proteus, Serratia, Escherichia coli, Staphylococcus aureus, Klebsiella and other good antibacterial effect, and no cross resistance with other aminoglycoside antibiotics. For sensitive bacteria caused by bronchitis, Pneumonia, pyelonephritis, peritonitis, cystitis, etc. |
| Toxicity | LD50 (of the sulfate salt) in mice (mg/kg): 380 i.v.; 400 s.c. (Nara, 1977) |
Extraction and refining
(1) After fermentation, the pH value of the fermentation broth was adjusted to 2.5 with concentrated sulfuric acid and stirred for 30min. Add about 7kg of filter aid (Radiolite No.600, Showa Kagaku Kcgyo Co,Ltd, Japan) and filter to remove microbial spores. The pH value of the filtrate was adjusted to 7.5 with 6mol/L sodium hydroxide.
(2) A column containing 20L cation exchange resin (Amberlite IRC-50, ammonium type) is introduced. Discard the effluent and the active substance is adsorbed on the resin. After the column was washed with water, it was eluted with 1mol/L ammonia. The eluent containing the active substance was collected and concentrated under reduced pressure to about 1L.
(3) The above concentrated solution is washed off with about 2L of water through a column containing 500ml of anion exchange resin (Dowex 1 × 2,OH type) to remove impurities and elute the active substance. The eluent containing the active substance was collected and concentrated under reduced pressure to about 100ml.
(4) Pass the above concentrate through a column containing 50ml of activated carbon powder. The active substance is adsorbed on the activated carbon. Wash with water first and discard it. The active substance was eluted with 0.1mol/L sulfuric acid. Collect the eluent containing the active substance.
(5) The eluate obtained above is passed through a column containing Dwex 44(OH type), and then the active substance is eluted with water. Collect the eluent containing the active substance and concentrate to about 50ml.
(6) Freeze-dry the concentrated solution to obtain 32g of crude powder containing fostimycin A. The activity of the crude product is 575 units/mg (every 1mg of pure product is equivalent to 1000 units).
(7)10g of the crude product is subjected to chromatography with a 500ml silica gel glass column. The eluent is a mixed solution of chloroform, isopropanol and 17% ammonia (volume ratio is 2:1:1), and the outflow speed is 50 ml/h. Fatimycin B was first eluted, followed by Fatimycin A. Collect the effluent containing Futimycin A and concentrate under reduced pressure until the solvent is completely removed.
(8) The concentrated solution is dissolved in a small amount of water and lyophilized to obtain 1.8g of pure fortimycin A, and its activity is 970 units/mg.
| specific rotation | D25 87.5° (c = 0.1 in water) |
Micromonospora olivoasterospora MK-70(ATCC 21819 or FERM-P No.1560) is used as the strain. The procedure is as follows:
1. seed preparation
(1) In a 50ml large test tube, 10m1 seed solution is released, and its composition is 0.1% glucose, 0.5% peptone, 0.5% yeast extract and 0.1% calcium carbonate (pH value is 7.5 before sterilization). A circle of strains was implanted and cultured at 30 ℃ for 5 days.
(2) In a 250ml conical flask, put 30ml of the second seed liquid (composition is the same as before). Implant 10ml of the first seed culture solution and oscillate at 30°C for 2d.
(3) In a 2L conical flask with a diverter plate, put 300ml of the third seed liquid (composition is the same as before). 30ml of the second seed culture medium was implanted and cultured at 30 ℃ for 2 days.
(4) In the 30L glass tank fermenter, 15L seed liquid (composition is the same as before). The third seed culture medium was implanted with 1.5L (equivalent to 5 bottles), and the culture was carried out at 37 ℃ for 2d under aeration (15L/min) and stirring (350r /min).
2. fermentation
In a 300L fermentation tank, 150L of main fermentation broth is installed. The composition of the main fermentation broth is 4% soluble starch, 2% soybean meal, 1% corn extract, 0.05% K2HPO4, 0.05% MgSO4?7H2O, 0.03% KCl and 0.1