A method for producing (-)trans-2, 3-epoxysuccinic acid(cas:110-15-6), which can be used as a good starting material for the sythesis of optically active compounds such as optically specific single β-lactam antibiotics, characterized in that filamentous fungi capable of producing (-)trans-2,3-epoxysuccinic acid(cas:110-15-6) are cultured in liquid medium while either ammonia, sodium hydroxide or potassium hydroxide is added to maintain the culture medium in a pH range of 5.0 to 7.5 throughout the culturing period.
The present invention is useful in a method of producing (-)trans-2,3-epoxysuccinic acid(cas:110-15-6) (hereinafter also referred to as the "acid"), a substance that is well known as a raw material for the synthesis of optically active compounds, by fermentation.
(-)trans-2,3-Epoxysuccinic acid(cas:110-15-6) is optically active, and is easily converted to β-hydroxy-L-aspartic acid under heating in aqueous ammonia solution [Journal of Medicinal Chemistry, 6, 233 (1963)]. This amino acid not only possesses antibacterial activity, but also works well as a raw material for optically specific single β-lactam antibiotics [Japanese Published unexamined patent application No. 106444/1984; Chemical and Pharmaceutical Bulletin, 33, 3798 (1985)].
As described above (-)trans-2,3-epoxysuccinic acid(cas:110-15-6) can be used as a good starting material for the synthesis of optically specific single β-lactam antibiotics. At the same time, it can be a compound that works well as a "chiral synton". It is therefore significant to establish an economically advantageous production method for this compound.
It is a well-known fact that (-)trans-2,3-epoxysuccinic acid(cas:110-15-6) is produced and accumulated in culture broth by a wide variety of filamentous fungi cultured in liquid medium [Journal of the Agricultural Chemical Society of Japan, 13,241 (1937); 14,362 (1938); 14, 1517 (1938); 16, 1015 (1940); Biochemical Journal, 39, 70 (1945); Journal of Bacteriology, 70, 405 (1955); U.S. Pat. No. 2,674,561 (1954); Journal of Medicinal Chemistry, 6, 233 (1963); Applied and Environmental Microbiology, 35, 1213 (1978)].
The desired products obtained using the method of the present invention were identified as (-)trans-2,3-epoxysuccinic acid(cas:110-15-6) by determining their physico-chemical properties including elemental composition, melting point, optical rotation and infrared spectrum. The quantitative determination of this acid in the culture medium or in the process of its isolation was achieved by high performance liquid chromatography (mobile phase: dilute aqueous solution of perchloric acid, pH 2.1; flow rate: 1.0 ml/min; detection wavelength: 214 nm) using a column packed with sulfonated polystyrene gel (Shimadzu SCR-101H column produced by Shimadzu Corporation in Japan, 7.9 mm×30 cm). Under these conditions, the retention time of this acid was about 5.6 minutes.
The detection of (-)trans-2,3-epoxysuccinic acid(cas:110-15-6) was achieved by thin layer chromatography using the following procedure.
Spot the sample on a cellulose plate (Merck & Co., Inc. in U.S.A.); develop the chromatograph with a mixture of diethyl ether, formic acid and water (7:2:1) at room temperature (about 25° C.) for 3 hours, and dry the plate in air; spray a 0.05% solution of bromophenol blue in ethanol on the plate: the acid is detected as a yellow spot on a blue-green ground with an Rf value of approximately 0.74.
Since it is optically active, the (-)trans-2,3-epoxysuccinic acid(cas:110-15-6) obtained according to the present invention can work well as raw material for the synthesis of compounds possessing optical specificity. For example, it is converted into β-hydroxy-L-aspartic acid when heated in aqueous ammonia solution, which can be converted to single β-lactam antibiotics possessing excellent antibacterial activity (Japanese Published unexamined patent application No. 106444/1984).
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