SU771106A1 - Method of preparing thiol-containing sorbents - Google Patents

Description

one

The invention relates to a process for the preparation of chemospecific sorbents, specifically to a method for the preparation of thiol-containing sorbents on an inorganic basis.

Chemospecific carriers,} Myo reactive thiol groups, are used in various fields of chemistry and biochemistry, for example, for selective chemisorption of heavy metal ions, including for the purification of biological fluids from such ions; for immobilization of proteins and enzymes for the purification of biopolymers by the method of chemospecific (covalent) chromattephaphy, etc. - Thanks to good mechanical strength, resistance to microbial contamination, availability, etc. quite widespread as matrices of different; such carriers have received such. inorganic materials such as porous glass, macroporous silica, diatomite, ceramics, etc.

Known and SH-containing sorbents on an inorganic basis. Such compounds are prepared, for example, by modification of an aminopropylated

macroporous silica (oc chrome) 1-oxo-2-ztoxy-3-thiolan-5-one which gives a sorbent with a capacity of SH groups up to 40 μm / g by 1- or treatment with N-acetyl homocysteine thiolactone amine propylated porous glass, which gives a sorbent with a capacity of SH- groups up to 30 microns / g 2,

Known methods include the treatment of an inorganic base having grafted functional groups from (yads of thio-containing compounds under mild conditions, as a rule, at room temperature in a solvent medium.

The known variants of the methods for the preparation of thiol-containing sorbents on an inorganic basis have a number of disadvantages: they allow us to produce derivatives with a sufficiently high capacity for SH-groups, the range of carriers obtained by known methods is also limited; In addition, the storage stability of sorbents with a free thiol group is not high due to the last exposure to O1, so either an inert atmosphere is required or the SHb groups of the sorbent are protected by subsequent chemical transformations. The closest to the technical essence is the process consisting in treating the aminopropyl macroporous silica in the medium of dry aprotic organic solvent (benzene, toluene) by 5-fold and higher excess of 1-oxo-2-ethoxy-3-thiolan-5-one for b h at room temperature Sh. manropore true .g) -ingg - nremnezezem method This method has the following disadvantages: - The method makes it possible to obtain a sorbent with a capacity of about 40 µm / g in SH-groups, which is only about 20% of the theoretical value; - The method makes it possible to obtain derivative of only one particular structure (III), i.e. does not possess universality. In addition, the reaction of excess (II) with (1) is complicated by no6o4HbnvQi processes, which are difficult to control and lead to the unreasonable expenditure of valuable reagent, the regeneration of which is not provided by this method. The aim of the invention is to increase the capacity of sorbents on an inorganic basis by SH-groups and the yield of the final product, as well as expanding the range of the resulting structure of sorbents. This goal is achieved by using the compound of the general formula PRX as the inorganic base, where P is macroporous silica (silochrome), diatomite (macroporous chromosor silica, covered with alumina (aluminum); R - - (CH) - - ( CH2) a-NHCO-CH2 - (CH-2) a-NHCO- (CH2) 2 -, - (CH2) a-NHCO-CHz-NHCO- (CH2 polyacrylic acid, floor acryl-K-minoethylamide X - -NHj , -COOY, where Y is a carbO imide, N-sukdinimidil, H nitrophenyl, ethoxycarbonyl as a thiol-containing compound, use a compound of the general formula, 1 where R: -CHj-, -CH (CH3) -, -CHjCH, -, -CHjCHCNHCOCH) - , (COOCH3); X is as above, and the treatment is carried out in an organic or aqueous medium with a ratio of the number of functional groups of the inorganic base and the amount of the thiol compound (in moles) 1: 1-20 for 1-24 hours, followed by treatment of the resulting compound with a reducing agent. According to the invention, a method for producing a thiol-containing sorbent on an inorganic basis is described by treating the latter with a total. formulas: PRX, where P is macroporous silica (silochrome), diatomite (chromosorb), macroporous silica coated with alumina (aluminum), and the values of R and X are defined above, a thiol-containing compound of the general formula where the values R and X are defined above, in organic or when the ratio of the amount of functional groups of the inorganic base to the amount of thiol-containing compound (in moles) is 1: 1-20 at 0-40 ° C for 1-24 h, followed by treatment of the obtained compound with a reducing agent. Cyclic 2-mercaptoethanol or sodium borohydride or dithiothreitol is used. The mechanism of the described method is as follows. For sorbent synthesis, compounds with a protected thiol function are used to inject sulfur into an inorganic base, and nitrophenyl sulphenyl derivatives (for example, an o-nitrophenyl sulphenyl group) are used as S-protective groups in the invention, which are simply prepared by the known method 3 by reacting nitrosulphenyl chloride with thiol acidic environment fl-B1, + H-L-CH “« / DIONCH.) iz x - –K –H1H z (or d 0 OH). EG The resulting mixed disulfides (VI) are stable in the absence of reducing agents and strong oxidizing agents but easily giveIOLs during recovery. In addition, S-nitrophenylsulphylene protection is a convenient form of protecting the thiol functions of the sorbent from acid oxidation by the air during storage of the product. The electron-acceptor effect of the aromatic system allows such S-protective groups to be used as activating SS-link for chemospecific xr mathematics by thiol-disulfide exchange. As the starting thiol-containing compound V, suitable substances are used: either mercaptocarboxylic acids, for example, thioglycolic, oi-mercaptopropionic, N-acetylcysteine, or aminothiols, for example, 2-mercaptoethylamine, cysteine methyl ester. As regards the method of adding a mixed YI disulfide to an inorganic base, the chemistry of this stage is determined both by the structure of the starting thiol V and the nature of the functional groups of the inorganic base. If, for example, S-nitrophenylsulfenyl derivative of mercaptocarboxylic acid is used, it is preferable to take NH in the reaction derivative of an inorganic base, which is activated by a known method, for example, carbodiimide, activated ether, mixed anhydride, carboxyl group of compound VI: CO g -f- | p-K-kneo-b -Y Sp. P-to-me about -kn or (the values of P, R, R and Y are as indicated above. If S-nitrophenylsulphenyl derivative of aminothiol is used, it is preferable to use a COOH containing media, activated by a known method, for example, ether activated carbodiimide , mixed anhydride, its carboxyl groups: PB-doOY4N HR- - IK. NO g PR-eONH-B- 31 P-K-eONH-R-H (P, R, R and Y values are as described above). In the synthesis reactions of compounds VIII, 1X, X1, and XII, according to the invention, mainly room temperature is envisaged, since its increase, although it accelerates the processes, but can have an undesirable destructive effect on the labile sulfur compounds. Therefore, it is preferable to use moderate temperatures (0-40 ° C). The synthesis time is determined by the reactivity of specific compounds, which is according to the invention. equal to 1-24 h. Organic solvents are usually used as the medium for carrying out the reactions, but it is also possible to use an aqueous medium (for example, in the case of water-soluble carbodiimide). When attached to an inorganic base, the S-nitrophenylsulfenyl derivative (VII or X) is taken in excess (usually not more than 20 times), and the excess reagent is easily regenerated and can be used again, which improves the economic performance of the process. The described method has the following advantages: - It makes it possible to obtain sorbents with a higher, compared to the prototype, capacity in SH-groups, reaching 90 µM / g for sorbents without a polymer coating and 300 µM / g for sorbents modified with polymers. The method allows to obtain a wide range of thiol-containing sorbents on various non-organic inorganic matrices. -The method involves the use of chemical reactions that provide almost unambiguous processes without noticeable side-by-side transformations, which allows to increase the yield of the target product of thiol functions attached to an inorganic basis; The method involves obtaining chemisorbents in a convenient storage form — with a protected thiol function which can be easily released under mild conditions before use. “The method involves the recovery of an excess of the most valuable component — the thiol-containing compound used.

Example 1. Method for producing thiol-containing cych sorbents of type IX.

The weighed amount of NH, - derived inorganic base is suspended in a solvent and a solution of S-nitrophenylsulfenyl compound VII is added in 1-20 times the amount (in moles) relative to the number of NHg-rpynn inorganic base. The suspension is stirred for 1-24 hours at, then the insoluble phase is separated by filtration, washed on the filter with a solvent, and dried in a vacuum desiccator over CaCI2 | The combined filtrate and washings are evaporated in vacuo to dryness, and the unreacted excess of the thio-containing reagent is recovered from the residue by known methods: reprecipitation, recrystallization. The reduction of the disulfide bonds of sorbent VIII is carried out by known methods.

for example, the action of an excess of 2-mer of captoethanol, an alcoholic solution of NaBHD, using dithiothreitol, and other known methods for the reduction of S-S bonds.

. Specific examples and conditions for the synthesis of products according to the method described are given in Table. one,

Example 2. Methodology for preparing thiol-containing sorbents of the type

g xii.

The synthesis of compounds of type XII is carried out according to the same procedure as in Example 1, but with the difference that the inorganic base derivative is used with activated

5 carboxyl group, which is treated with a 1-20-fold amount (in moles x) relative to the number of CCOH groups of the inorganic base of the thiol-containing compound X,

0 Specific examples and conditions for the synthesis of sorbents by this method are given in Table. 2,

Claims (3)

1. The catalog of the firm Pierce (USA), 1977-78, p.228. 2. Authors certificate of the USSR 540870, cl. C 07 F 7/18, 1975 (prototype). five 3.A. Fontana Sulfenyl Halide E as Modifying Reagents for Polypeptides and Proteins, Biochemistry, 2, 3, 1968, p.980.