JPH01252604A - 5-fluorouracil carrier - Google Patents

Abstract

PURPOSE:To obtain a 5-fluorouracil carrier having excellent antitumor activity and low toxicity, by reacting chitosan with chloroacetic acid and acetic anhydride and then reacting the obtd. compd. with 5-fluorouracil and triethylamine. CONSTITUTION:A chitosan deriv. of formula II (wherein m is 1-2; n is 1-2) is prepd. by reacting chitosan of formula I (wherein r is 100 or larger) with chloroacetic acid and acetic anhydride. Then, a 5-fluorouracil carrier of formula IV wherein 5-fluorouracil is bound by an amide bond and an ester bond through a lower alkylene group to the 2- and 6-positions of chitosan is obtd. by reacting the chitosan deriv. of formula II with 5-fluorouracil of formula III and triethylamine. This carrier is incorporated into tumor cells as it is and releases in the cells 5-fluorouracil which exhibits antitumor activity, and chitosan which is the carrier is decomposed and absorbed.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a 5-fluorouracil support with an amide bond and an ester bond via an alkylene group to the 2- and 6-positions of chitosan, a method for producing the same, and a method for supporting the same. The present invention relates to an antitumor agent consisting of the body.

(Prior art) Chitin is a tissue polysaccharide that forms the exoskeleton of crustaceans and fungi, and has a chemical structure and physical properties very similar to cellulose.
It is an extremely abundant resource on earth. This chitin has a strong crystal structure and lacks solubility and reactivity. However, chitosan, which is obtained by deacetylating chitin under strong alkaline conditions, becomes water-soluble when a salt is made, and chitin can also be hydroxyethylated by ethylene oxide. The resulting glycolized chitin also becomes water-soluble, making it easier to chemically modify it.

These chitins and their derivatives are polymeric substances that generally have many properties suitable for biomaterials, such as low toxicity and biodegradability and absorption. Among these, partially N-acetylated chitin or partially N-acetylated chitosan selectively aggregates leukemia L1210 dehydrated cancer cells and inhibits their proliferation. Acetyl chitooligo (especially hexaose)
It has been reported in recent years that it exhibits strong immunostimulatory antitumor activity.
Chitin and chitin are attracting attention as polysaccharides having antitumor S activity (for example, JP-A-59-27826;
No. 62-123123). In this way, chitin and chitosan have low toxicity, are biodegradable and absorbable, and have the ability to selectively accumulate in tumor cells, so from a different perspective, they meet the requirements as carriers for polymeric drugs. I can say that there is.

On the other hand, 5-fluorouracil (5FU) is an antitumor agent that acts as an antimetabolite inhibitor, and has strong antitumor activity as well as strong toxicity, and has been reported to be effective in suppressing its side effects.

(Problems to be Solved by the Invention) Therefore, the object of the present invention is to provide chitin and chitosan compounds and antitumor compounds having such antitumor S activity, low toxicity, biodegradability and absorption ability, and ability to selectively accumulate in tumor cells. The object of the present invention is to provide a novel compound in combination with 5-FU that is useful as a drug.

(Means for Solving the Problems) The present inventor carries 5FU by covalent bonding to a chitin derivative, expecting to reduce the side effects of 5FU, maintain drug efficacy, increase targeting, and increase activity. Macromolecular Prodrug
From this point of view, the binding mode of 5FU-carrying, the presence or absence of a spacer, and whether it is glycolated or not.

The influence on antitumor activity was investigated, and in the course of this investigation, it was determined whether 5-fluorouracil was supported at the 2- and 6-positions of chitosan by amide and ester bonds via lower alkylene groups represented by the following formula (I), It has been found that this compound exhibits excellent antitumor S activity, and the present invention has been completed.

That is, the present invention provides (1) a 5-fluorouracil support with amide bonds and ester bonds via lower alkylene groups to the 2- and 6-positions of chitosan represented by formula (I), ~2. n = 1 to 2, r = an integer of 100 or more) -An antitumor agent containing a fluorouracil carrier.

(3) Reacting chitosan with chloroacetic acid and acetic anhydride,
A chitosan derivative of the formula (II) (m = 1 to 2, n = 1 to 2, r = an integer of 100 or more) was obtained, and this compound was reacted with 5-fluorouracil and triethylamine. The present invention provides a method for producing a 5-fluorouracil support represented by the formula (I).

This 5FU carrier is taken up into tumor cells as it is, where it releases 5FU and acts as 5FU, and the carrier chitosan is decomposed and absorbed after achieving its purpose.

Therefore, it is preferable that the dose be approximately equivalent to conventional 5FU in terms of 5F'U.

(Example) Next, the present invention will be explained in more detail based on examples.

Example 1 (Synthesis of Compound 2) 0.8 g of chitosan 1 (Pn=1800) was dissolved in 35 g (O17 mol) of chloroacetic acid, and 7
After stirring at 0°C for 2 hours, 35% acetic anhydride (0,:14
The reaction mixture was added to 300 ml of ice water, and the resulting precipitate was thoroughly washed with distilled water to obtain 2.

Identification of 2: II ((KBr disk) [c+s-'l; 1
740 (C=010-acyl), 155Q (C
=O10-acyl), Isco0 (Nll
/N-acyl), 780 (C-CI) Example 2 20.3 g of 2 3 (I) was added to D
After dissolving with MSO50d for about 3 hours, add 5
Add FU3 0.65 g (5 mmol), triethylamine 0, 71 rll ((5 mmol),
The mixture was stirred at 0°C for 24 hours. After the reaction, the reaction mixture solution was poured into acetone to obtain a precipitated polymer. This was washed with pyridine chloroform to obtain the target polymer (I)-1.

Identification of polymer (I)-1 Ill (KBr disk) [cm-']; 1
750-1680 (C=010-acyl and C=0
15FU), +660 (C=010-acyl),
1540(N!I/N-acyl), 1050(
C-0-C), 780 (C-CI) disappearance (I)-
Since 1 is insoluble in all solvents, it is partially refluxed in a 3N-NaOH solution for 2 days to completely hydrolyze the ester bond, and the 1-carboxymethyl 5FU present in the solution is removed.
3N-NaO11:272nm1.
3N-Na011 = 66701118X
ll1a
Using X as a reference, use the UV spectrum method! The introduction of 5FU per glucosamine unit: Jl (D5FU) was calculated by:

Trial $4(I)-1 D5FU=116% Pn=1800 Insoluble in both water and organic solvent Example 3 10.3g was dissolved in 50ml of DMSO and 2.6g of 5FU3 (2011sol), triethylamine 2,8 Add d (20+amol), 6
After reacting at 0° C. for 24 hours, polymer (I)-2 was taken out in the same manner as in Example 2, and the introduction rate of 5FLJ was determined.

Sample (I)-2 D5FU = 116% Pn = 1800 Insoluble in both water and organic solvent Example 4 (antitumor activity test) P-3881ymphoc in CDF1 mice (5 withdrawals)
ytic Ieukcsia (leukemia) cells in 1xl
O6/mouse was administered intraperitoneally, and a predetermined amount of the polymer of formula (I) was administered intraperitoneally once on the next day and on the 5th day.

For the experimental group, 6 animals were used for each dose level, and for the control group, 30 animals were used. The antitumor activity was evaluated using the survival days ratio shown in Table 1 using the following formula, and the results are shown in Table 1.

Note (1)-2 in Table 1 is insoluble in water, so 5orbate 8
0 was used and administered in the form of a C suspension.

Note that if the T/C value is 120 or more, the sample is evaluated as having activity.

[Acute toxicity test] The compound of formula (I) was administered to mice, but the dose was 80
At doses up to 0 mg/kg, no rapid weight loss was observed in mice, and it can be concluded that there is no acute toxicity.

Therefore, it can be said that the LD50 is also 800 g/kg or more.

[Release behavior test of 5FU] Release of compound (I)-1 or (I)-2 of the present invention at 37°C in 0.01 N -N a OHlo, IN-HCu, physiological saline or phosphate buffer. As a result of the hydrolysis, in vitro, this compound is susceptible to alkaline decomposition, resulting in (I)-1 or (I)-
When 2 undergoes hydrolysis, l-carboxymethyl 5FU
I found out that it will be released first.

(Effects of the Invention) The 5FU carrier of the present invention has excellent 5FU release properties, exhibits anti-rM tumor activity, and is a useful compound with low toxicity.

Claims (4)

[Claims] (1) 2nd and 6th positions of chitosan represented by formula (I)
5-fluorouracil support with an amide bond and an ester bond via a lower alkylene group to the position. ▲There are mathematical formulas, chemical formulas, tables, etc.▼... (I) (However, m = 1 to 2, n = 1 to 2, and r = an integer of 100 or more.) (2) The 5-fluorouracil support according to claim 1, wherein the lower alkylene groups at the 2-position and the 6-position are both methylene groups. (3) An antitumor agent containing 5-fluorouracil supported by an amide bond and an ester bond via lower alkylene groups at the 2- and 6-positions of the chitosan according to claim 1, represented by the formula (I). (4) Reacting chitosan with chloroacetic acid and acetic anhydride,
A chitosan derivative of formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (where m = 1 to 2, n = 1 to 2, r = an integer of 100 or more) was obtained, and this compound A method for producing a 5-fluorouracil carrier according to claim 1, which comprises reacting 5-fluorouracil with triethylamine.