JPH0699462B2 - Lactose higher fatty acid derivative - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel lactose higher fatty acid derivative useful as a component of a preparation having organ-tropicity, particularly, a hepatocyte-specific affinity, for example, a liposome. .

More specifically, the present invention provides the following formula (I): (In the formula, R represents a hydrogen atom or an acyl group, and COR ¹ is
Shows the fatty acid residue of C ₁₂ -C _30, Indicates an α or β bond. ) Relates to a lactose higher fatty acid derivative.

[Conventional technology]

In the fields of pharmacy and medicine, organ-directed preparations have attracted attention, and some proposals have been made regarding the technology of selectively delivering a drug to a desired organ by, for example, administering the drug by incorporating it into a liposome. Has been. Among these, regarding hepatocyte-directed liposomes, JP-A-55-98121, Biokimica / Bakiofuidika / Acta (BBA), Volume 497, 760-765 (1977) and 734
Vol. 40-47 (1983), and asialoganglioside-blended liposomes and fatty acid diester-blended liposomes of digalactosylglyceride have been proposed. However, these compounding agents are natural products, have the disadvantages of being difficult to obtain and expensive, and are extremely difficult to produce industrially in practice, and their use is severely restricted. .

Under such circumstances, there is a demand for a compounding agent useful for producing an easily available and satisfactory specific liver parenchymal cell-directed liposome, but such a compounding agent cannot be provided yet. Is.

[Details of Invention]

The present inventors have conducted research to develop a compounding component of liposomes having satisfactory specific organ-tropism. As a result, they have discovered that the novel lactose higher fatty acid derivative represented by the above formula (I) can exist stably and can be easily synthesized, and succeeded in its synthesis. Furthermore, a preparation in which the novel compound is bound to a liposome, that is, a lipid membrane structure has a specific affinity for hepatic parenchymal cells, and therefore, is extremely useful in the field of liver-directed preparations which is extremely useful as a compound for liposome formulation. It was discovered that it should be a novel compound.

Therefore, an object of the present invention is to provide a novel lactose higher fatty acid derivative useful as, for example, a liposome formulation component.

These and many other objects and advantages of the present invention will become more apparent from the description below.

In the lactose higher fatty acid derivative represented by the above formula (I) of the present invention, the compound in which R is an acyl group is an intermediate for producing a compound in which R is a hydrogen atom, and is easily prepared by a deacylation method known per se. Can be converted into a compound in which R is a hydrogen atom. Further, a compound in which R is a hydrogen atom can be converted into a compound in which R is an acyl group by utilizing an acylation method known per se.

In the lactose higher fatty acid derivative represented by the formula (I) of the present invention, it is not necessary that all Rs are hydrogen atoms or acyl groups, but it is usual that either R is a hydrogen atom or an acyl group. Examples of the acyl group include, for example, lower acyl groups derived from lower fatty acids such as formic acid, acetic acid, propionic acid and butyric acid, and acyl groups derived from aromatic carboxylic acids such as benzoic acid and paranitrobenzoic acid. It can be illustrated. Among these, an acetyl group or a benzoyl group can be preferably exemplified.
Further, COR ¹ wherein, R ¹ represents an alkyl group of C ₁₁ -C ₂₃ saturated or unsaturated] In formula (I) represents a fatty acid residue of C ₁₂ -C _30, preferably C ₁₂ -C ₂₂ fatty acid residues can be exemplified. Examples of C _{12 to} C ₃₀ fatty acids from which such fatty acid residues are derived include the following fatty acids. That is, lauric acid, n-tridecanoic acid, myristic acid, n-pentadecanoic acid, barmitic acid, n-heptadecanoic acid, stearic acid, n-nonadecanoic acid, arachidic acid, n-henicosanoic acid, behenic acid, tricosanoic acid, serotic acid, Melisic acid, palmitooleic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, erucic acid and brassic acid. Of these, arachidic acid is particularly preferable.

The compound of formula (I) of the present invention is, for example, a compound represented by the following formula (II): (However, in the formula, Is synonymous with the above. ) 2,2 ', 3,3', 4 ', 6,6'-hepta-O-acyl-lactosylamine or lactosylamine represented by
It can be produced by acid-amide bond of C _{12 to} C ₃₀ fatty acid. When the former lactosylamine is used, R can be converted to a compound in which R is a hydrogen atom in the above formula (I) by deacylating the obtained compound. When the latter lactosylamine is used, the compound obtained can be converted to a compound in which R is an acyl group in the above formula (I) by acylation. It is preferable to employ the former reaction using lactosylamine.

According to this preferred embodiment 2, 2 ', 3,3', 4 ', 6,6'-hepta -O- acyl - reacting lactosyl amine and fatty acid C ₁₂ -C ₃₀ in the presence of a condensing reagent A compound of formula (I) in which R is an acyl group can be easily produced by a method known per se. Instead of the above-mentioned method of reacting a C ₁₂ -C ₃₀ fatty acid in the presence of a condensation reagent, a C ₁₂ -C ₃₀ fatty acid halide such as chloride is reacted in the absence of a condensation reagent. Hiring is C1-
This is disadvantageous because the substantial formation of compounds other than the compound of formula (I) in which NH ₂ is di-substituted by —CO (CH ₂ ) _n —CH ₃ is difficult to avoid.

The reaction can be carried out in the presence of elution such as e.g. tetrahydrofuran, dimethylformamide, dichloromethane, ethyl acetate, methanol, ethanol, benzene, suitable mixed elutions thereof and the like. There are no particular restrictions on the amount used, but for example, it is about 10 with respect to the compound of formula (II).
The amount to be used can be exemplified. Further, examples of condensation reagents to be used include, for example,
N, N'-dicyclohexylcarbodiimide (DCC), N-
Ethyl-5-phenylisoxazolium-3'-sulfonate, diphenylketene-P-tolylimine, 1-
Ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ), N-isobutyloxycarbonyl-2
-Iso-butyloxy-1,2-dihydroquinoline (IID
Examples thereof include Q) and diethylphosphorus cyanide (DEPC). Although the amount used can be appropriately selected and changed, for example, the amount used is about 1 to about 3 mol per 1 mol of the compound of the formula (II). Further, the amount of the C _{12 to} C ₃₀ fatty acid used with respect to the compound of the formula (II) can be appropriately selected and changed.
I) The amount used may be about 1 to 3 mol per 1 mol of the compound.

The reaction temperature and time can also be appropriately selected and changed, for example, about −
Illustrative are reaction temperatures such as 10 ° to about + 50 ° C, preferably about 0 ° to about 30 ° C, and reaction times such as about 2 to about 72 hours.

The compound of formula (I) in which R is an acyl group, which can be obtained as described above, can be easily converted into a compound of formula (I) in which R is a hydrogen atom by subjecting it to a deacylation reaction known per se. Can be converted. The deacylation reaction can be easily performed, for example, by treating the compound of formula (I) in which R is an acyl group with a deacylating agent in the presence of a solvent.

In carrying out the deacylation procedure, for example, methanol,
A compound of formula (I) in which a polar solvent such as ethanol or the like or a mixed solvent R such as methanol-chloroform or the like is an acyl group is dissolved, and the compound is treated with an alkali such as sodium alkoxide such as sodium methylate, ammonia gas or triethylamine. It can be done by processing.

The reaction temperature and time can also be appropriately selected and changed, for example, about 0
Reaction temperatures such as ° to about 40 ° C and reaction times such as for example about 1 to about 10 hours can be mentioned.

After completion of the reaction, the target compound of formula (I) can be separated and purified, if necessary, by utilizing a separation / purification means known per se such as solvent removal, crystallization, column chromatography and the like.

In the compound of the formula (I) of the present invention, the compound in which R is a hydrogen atom is, as described above, useful as a component of the liposome in the field of liver-directed preparations having a specific affinity for hepatocytes. The compound of formula (I) in which R is an acyl group is also useful as an intermediate for forming a compound in which R is a hydrogen atom. The liposome composition containing the compound of the formula (I) of the present invention in which R is a hydrogen atom is excellent in a form in which, for example, a suitable pharmacologically active compound is contained in the liposome formed by the composition. It can be a liver-directed drug.

In the test examples below, the liposome formed by the liposome composition containing the compound of the formula (I) of the present invention in which R is a hydrogen atom has a lactose moiety (or a lactose moiety at the end of the lactose) of a liposome (spherical membrane). It shows that it has an excellent liver parenchyma directivity, which is presumed to have a protruding morphology on the surface.

Reference Example 1 2,2 ', 3,3', 4 ', 6,6'-hepta-O-acetyl-β-
Lactosyl azide (Compound 1) To 10 g of lactose, 80 ml of pyridine and 50 ml of acetic anhydride were added,
Stir overnight at room temperature. The product was treated by a conventional method to obtain 19.5 g (yield 98.5%) of white powdery 1,2,2 ', 3,3', 4 ', 6,6'-octa-O-acetyl-lactose. It was This was dissolved in 40 ml of dichloromethane, 90 ml (30% w / v) of a hydrogen bromide saturated acetic acid solution was added under ice cooling, and the mixture was stirred at 0 ° C for 15 hours. The reaction solution was poured into ice water, extracted with chloroform, washed with ice water and ice-cold sodium hydrogen carbonate water in this order, dried (anhydrous magnesium sulfate) and concentrated to obtain 22.6 g of crude bromide.
22.6 g of the obtained crude bromide was added to 160 ml of dimethylformamide.
40 g of soda was added and the mixture was stirred overnight. The reaction mixture was poured into ice water, extracted with chloroform, ice water,
The extract was washed with 5% aqueous hydrochloric acid and ice-cold aqueous sodium hydrogen carbonate and then dried to obtain 21.2 g of crude azide. This was subjected to silica gel chromatography (solvent system: chloroform-acetone (30:
1)] and the above compound 1 was obtained.

Yield; 15 g mp; 70-73 ° (literature value 72-74 °) ▲ [α] ²² _D ▼; −20.5 ° (C1.0, chloroform) (literature value −22 °) IR (KBr) 1750 (OAc) , 2130 (N ₃ ) Elemental analysis value; Calculated value as C ₂₆ H ₃₅ N ₃ O ₁₇ (Molecular weight, 661.58); C, 47.20; H, 5.33; N, 6.35 Experimental value; C, 47.00; H, 5,54 N, 6.06 Reference Example 2 2,2 ', 3,3', 4 ', 6,6'-hepta-O-acetyl-β-
Lactosylamine (Compound 2) 1.61 g of the above compound was dissolved in 250 ml of methanol, and catalytically reduced in the presence of 600 mg of platinum dioxide for 1.5 hours, then the catalyst was filtered off through Celite, and the filtrate was concentrated to give a specific crystallite as a compound. Got 2.

Yield; 5.3 g TLC; Rf value = 0.3 (chloroform: ethanol = 19: 1) ▲ [α] ²² _D ▼; + 8.0 ° (C = 1.0, ethanol) (literature value 8.6 °) Example 1 1-N -Eicosanoyl-1-deoxy-2,2 ', 3,3',
4 ', 6,6'-Hepta-O-acetyl-β-lactosylamine The above compound 2 5.3 g was dissolved in ethanol 200 ml, and arachidic acid 5.6 g dissolved in benzene 200 ml was added thereto, followed by N-ethoxy. Carbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) (4.5 g) was added, and the mixture was stirred at room temperature for 48 hours. The reaction solution was cooled, the precipitated unreacted arachidic acid was filtered off, and the filtrate was concentrated. The obtained residue was purified by silica gel chromatography [solvent system; chloroform-acetone (30: 1)] to obtain a white powdery substance of the present invention.

Yield: 6.5 g ▲ [α] ²² _D ▼; 21.5 ° (C = 1.5, chloroform) TLC; Rf value = 0.45 (chloroform: acetone = 6: 1) ¹ H-NMR (90 MHz, CDCl ₃ / TMS); δ , 0.80 ~ 1.60 (39H, Eico
sanoyl) 1.97 to 2.20 (21H, all S, OAc × 7) 6.22 (d, 1H,
J _{NH, 1} = 9Hz, NH) IR (KBr); 3300 (NH), 1750 (OAc) 1680 (amide I) 1
545 (Amide II) Elemental analysis value; Calculated value as C ₄₆ H ₇₅ O ₁₈ N (molecular weight 930.10); C 59.40, H 8.13, N 1.51% Experimental value; C 59.51, H 8.09, N 1.47% Example 2 1- N-eicosanoyl-1-deoxy-β-lactosylamine 5 g of the product of Example 1 was added to 45 ml of chloroform and 130 m of methanol.
Dissolve in l and add 200 mg of sodium methylate,
Stir for hours. The generated precipitate was collected by filtration and then thoroughly washed with methanol and ether to obtain the substance of the present invention.

Yield: 3.1 g mp; 253-254 ° ▲ (α) ²² _D ▼; 18.63 ° (C1.2, dimethylsulfoxide) ¹ H-NMR (90 MHz, DMSO-d _{6 /} TMS); δ 0.80-1.50 (39 H , Eic
osanoyl) 4.60 (d, 1H, J _{NH, 1} = 10Hz, NH) IR (KBr); 3400-3300 (OH, NH), 1670 (amide I) 155
5 (Amide II) Elemental analysis value; Calculated value as C ₃₂ H ₆₁ O ₁₁ N (molecular weight 635.83); C 60.45, H 9.67, N 2.20% Experimental value; C 60.22, H 9.57, N 2.12% Example 3 1- N-lauroyl-1-deoxy-2,2 ', 3,3', 4 ',
6,6′-Hepta-O-acetyl-β-lactosylamine A substance of the present invention was obtained in the same manner as in Example 1 except that 5.6 g of arachidic acid in Example 1 was changed to 3.6 g of lauric acid.

Yield; 5.80 g TLC; Rf value = 0.43 (chloroform: acetone = 6: 1) ¹ H-NMR (90 MHz, CDCl _{3 /} TMS); δ0.80 to 1.60 (23H, Lauro
yl) 1.97 to 2.21 (21H, all S, OAc × 7) 6.22 (d, 1H, J
_{NH, 1} = 9Hz, NH) IR (KBr); 3300 (NH), 1750 (OAc) 1670 (amide I) 1
540 (amide II) Elemental analysis value; Calculated value as C ₃₈ H ₅₉ O ₁₈ N (molecular weight 817.87); C 55.81, H 7.27, N 1.71% Experimental value; C 55.42, H 7.62, N 1.66% Example 4 1- N-lauroyl-1-deoxy-β-D-lactosylamine 3 g of the product of Example 3 was dissolved in 80 ml of anhydrous methanol, 120 mg of sodium methylate was added, and the same procedure as in Example 2 was carried out to obtain the substance of the present invention. .

Yield; 1.63g ¹ H-NMR (90MHz, DMSO-d _{6 /} TMS); δ 0.80 to 1.50 (23H, Lau
royl) 4.60 (d, 1H, J _{NH, 1} = 10Hz, NH) IR (KBr); 3400-3300 (OH, NH), 1670 (amide I) 154
0 (amide II) Elemental analysis value; Calculated value as C ₂₄ H ₄₅ O ₁₁ N (molecular weight 523.61); C 55.05, H 8.66, N 2.68 Experimental value; C 54.76, H 8.49, N 2.75 Example 5 1-N -Myristoyl-1-deoxy-2,2 ', 3,3',
4 ′, 6,6′-Hepta-O-acetyl-β-lactosylamine The procedure of Example 1 was repeated except that 5.6 g of arachidic acid of Example 1 was changed to 4.2 g of myristic acid to obtain the substance of the present invention. Obtained.

Yield; 5.20 g TLC; Rf value = 0.43 (chloroform: acetone = 6: 1) ¹ H-NMR (90 MHz, CDCl _{3 /} TMS); δ0.80 to 1.60 (27H, Myris
toyl) 1.97 to 2.22 (21H, all S, OAc × 7) 6.22 (d, 1H, J
_{NH, 1} = 9Hz, NH) IR (KBr); 3300 (NH), 1750 (OAc) 1675 (amide I) 1
540 (amide II) Elemental analysis value; Calculated value as C ₄₀ H ₆₃ O ₁₈ N (molecular weight 845.93); C 56.79, H 7.51, N 1.66% Experimental value; C 56.22, H 7.71, N 1.61% Example 6 1- N-myristoyl-1-deoxy-β-lactosylamine 3 g of the product of Example 5 was dissolved in 100 ml of anhydrous methanol, 120 mg of sodium methylate was added, and the same procedure as in Example 2 was carried out to obtain the substance of the present invention.

Yield; 1.7 g ¹ H-NMR (90 MHz, DMSO-d _{6 /} TMS); δ 0.80 to 1.50 (27 H, Myr
istoyl) 4.60 (d, 1H, J _{NH, 1} = 10Hz, NH) IR (KBr); 3400-3300 (OH, NH) 1670 (amide I) 1540
(Amide II) Elemental analysis value; Calculated value as C ₂₆ H ₄₉ O ₁₁ N (molecular weight 551.67); C 56.61, H 8.95, N 2.54 Experimental value; C 56.80, H 8.80, N 2.51 Example 7 1-N-palmitoyl -1-deoxy-2,2 ', 3,3',
4 ′, 6,6′-Hepta-O-acetyl-β-lactosylamine The procedure of Example 1 was repeated except that 5.6 g of arachidic acid of Example 1 was changed to 4.6 g of palmitic acid to obtain the substance of the present invention. Obtained.

Yield; 5.6 g TLC; Rf value = 0.45 (chloroform: acetone = 6: 1) ¹ H-NMR (90 MHz, CDCl _{3 /} TMS); δ 0.80 to 1.60 (31 H, Palmi
toyl) 1.97 to 2.22 (21H, all S, OAc × 7) 6.22 (d, 1H, J
_{NH, 1} = 9Hz, NH) IR (KBr); 3300 (NH) 1750 (OAc) 1670 (amide I) 154
0 (amide II) Elemental analysis value; Calculated value as C ₄₂ H ₆₇ O ₁₈ N (molecular weight 873.98); C 57.72, H 7.73, N 1.60% Experimental value; C 58.02, H 7.41, N 1.70% Example 81- N-palmitoyl-1-deoxy-β-lactosylamine 3 g of the product of Example 7 was treated in the same manner as in Example 2 to obtain the substance of the present invention.

Yield: 1.8g ¹ H-NMR (90MHz, DMSO-d _{6 /} TMS); δ 0.80 ~ 1.52 (31H, Pal
mitoyl) 4.60 (d, 1H, J _{NH, 1} = 10Hz, NH) IR (KBr); 3400-3300 (OH, NH) 1670 (amide I) 1540
(Amide II) Elemental analysis value; Calculated value as C ₂₈ H ₅₃ O ₁₁ N (molecular weight 579.72); C 58.01, H 9.21, N 2.42% Experimental value; C 58.22, H 9.43, N 2.22% Example 9 1-N -Stearoyl-1-deoxy-2,2 ', 3,3',
4 ′, 6,6′-Hepta-O-acetyl-β-lactosylamine The procedure of Example 1 was repeated except that 5.6 g of arachidic acid of Example 1 was changed to 5.1 g of stearic acid to give the substance of the present invention. Obtained.

Yield; 5.9g TLC; Rf value = 0.45 (chloroform: acetone = 6: 1) ¹ H-NMR (90MHz, CDCl _{3 /} TMS); δ0.80 to 1.60 (35H, Stear
oyl) 1.97 to 2.22 (21H, all S, OAc × 7) 6.22 (d, 1H, J
_{NH, 1} = 9Hz, NH) IR (KBr); 3300 (NH) 1750 (OAc), 1670 (amide I) 1
540 (amide II) Elemental analysis value; Calculated value as C ₄₄ H ₇₁ O ₁₈ N (molecular weight 902.04); C 58.59, H 7.93, N 1.55% Experimental value; C 58.79, H 8.13, N 1.70% Example 10 1- N-Stearoyl-1-deoxy-β-lactosylamine 3 g of the product of Example 9 was treated in the same manner as in Example 2 to obtain the substance of the present invention.

Yield; 1.7 g ¹ H-NMR (90 MHz, DMSO-d _{6 /} TMS); δ 0.80 to 1.50 (35 H, Ste
aroyl) 4.60 (d, 1H, J _{NH, 1} = 10Hz, NH) IR (KBr); 3400-3300 (OH, NH) 1670 (amide I) 1540
(Amide II) Elemental analysis value; Calculated value as C ₃₀ H ₅₇ O ₁₁ N (molecular weight 607.78); C 59.29, H 9.45, N 2.30% Experimental value; C 59.51, H 9.66, N 2.62% Example 11 1-N -Oleoyl-1-deoxy-2,2 ', 3,3', 4 ',
6,6′-Hepta-O-benzoyl-β-lactosylamine 2,2 ′, 3,3 ′ was operated in the same manner as in Reference Example 1 except that 50 ml of acetic anhydride in Reference Example 1 was changed to 40 ml of benzoyl chloride. , 4 ′, 6,
6'-hepta-O-benzoyl-β-lactosyl azide 1
7.5 g (yield 70%) was obtained. This 10 g was treated in the same manner as in Reference Example 2 to obtain 8.2 g of 2,2 ', 3,3', 4 ', 6,6'-hepta-O-benzoyl-β-lactosylamine.

Then, the compound of the present invention was obtained in the same manner as in Example 1 except that 8.8 g of this compound was changed to 5.1 g of oleic acid in place of 5.6 g of arachidic acid in Example 1.

Yield; 8.4 g TLC; Rf value = 0.43 (chloroform: acetone = 6: 1) ¹ H-NMR (90 MHz, CDCl _{3 /} TMS); δ 0.80 to 1.60 (33 H, Oleoy
l) 6.22 (d, 1H, J _{NH, 1} = 9Hz, NH) 7.2 to 8.3 (35H, Bz ×
7) IR (KBr); 3300 (NH) 1750 (OBz) 1670 (Amide I) 154
0 (amide II) Elemental analysis value; Calculated value as C ₈₁ H ₈₉ O ₁₈ N (molecular weight 1364.59); C 71.30, H 6.57, N 1.03% Experimental value; C 70.90, H 6.99, N 0.99% Example 12 1- N-oleoyl-1-deoxy-β-lactosylamine 5 g of the product of Example 11 was treated in the same manner as in Example 2 to obtain the substance of the present invention.

Yield: 1.8 g (82.1% yield) ¹ H-NMR (90 MHz, DMSO-d _{6 /} TMS); δ 0.80 to 1.50 (33 H, Ole
oyl) 4.60 (d, 1H, J _{NH, 1} = 10Hz, NH) IR (KBr); 3400-3300 (OH, NH) 1670 (amide I) 1555
(Amide II) Elemental analysis value; Calculated value as C ₃₀ H ₅₅ O ₁₁ N (molecular weight 605.76); C 59.48, H 9.15, N 2.31% Experimental value; C 59.77, H 9.50, N 2.18% Test example (1) Liposomes Preparation of I (containing the substance of the present invention) L-α-dimyristoylphosphatidylcholine 68.8 μmo
l, cholesterol 68.8 μmol, dicetyl phosphate 6.
8 μmol and 16 μmol of the substance of the present invention of Example 2 were dissolved in a mixture of chloroform and methanol (2: 1). This was added to a test tube, the solvent was distilled off in a nitrogen gas stream, and ³ H-inulin was added.
A suspension of liposomes was prepared by adding 6 ml of 1 mM inulin phosphate-buffered saline containing 240 μCi, shaking, and sonicating lightly. This was heated to 40 to 45 ° and then passed through a polycarbonate membrane filter having a pore size of 0.2 μm to prepare a suspension of liposomes having a particle size of 0.2 μm or less. Then, this was subjected to ultracentrifugation (150,000 × g, 1 hour, twice) to remove the inulin not retained by the liposomes by removing the supernatant, and adding phosphate buffered saline to a total volume of 5.62 ml. A suspension of liposomes was obtained. L-α-dimyristoylphosphatidylcholine was quantified by an enzymatic method using the choline group as a marker, and the resulting suspension had a total lipid content of 10 μm per 0.5 ml.
It had ol lipid. Also, this liposome suspension
0.64 μCi of inulin per 0.5 ml was retained in the liposome.

(2) Preparation of liposome II (containing the substance of the present invention) L-α-dimyristoylphosphatidylcholine 72.4 μmo
l, cholesterol 72.4 μmol, dicetyl phosphate 7.
2 μmol and 8 μmol of the substance of the present invention of Example 2 were treated in the same manner as in (1) above except that the mixture was dissolved in a mixture of chloroform and methanol to obtain a total liposome suspension of 5.9 ml. The obtained suspension retained 10 μmol of total lipid and 0.78 μCi of inulin as total lipid in 0.5 ml per liposome.

(3) Preparation of liposome III (control) L-α-dimyristoylphosphatidylcholine 76.2 μmo
l, cholesterol 76.2 μmol, dicetyl phosphate 7.
The procedure of (1) was repeated except that 6 μmol was dissolved in chloroform to obtain a total volume of 5.0 ml of a liposome suspension. The obtained suspension retained 10 μmol of total lipid and 1.29 μCi of inulin as total lipid in 0.5 ml per liposome.

(4) Preparation of ³ H-inulin solution (control) 6 ml of 1 mM inulin phosphate-buffered saline containing 240 μCi of ³ H-inulin was diluted 20-fold with phosphate-buffered saline, A solution containing 1 μCi of inulin per 0.5 ml total was prepared.

Test 1 A portion of the liposome suspension obtained in (1) and (3) was taken, and phosphate-buffered saline was added to make the total lipid.
It was diluted to 0.5 μmol / ml. Separately, a lectin having a sugar specificity to β-D-galactose (Rici
nus Communis), Sigma) 100 μg / ml, 2 each
Phosphate buffered saline containing 00 μg / ml was prepared. Next, the liposome suspension and the lectin solution were mixed at a ratio of 1: 1 and shaken lightly and dispensed into a spectrophotometer measurement cell,
The transmittance at a wavelength of 450 nm was measured over time (15 minutes). In the suspension of liposomes containing the substance of the present invention in Test Example (1), the aggregation of the liposomes was observed due to the decrease in the transmittance with time, and the extent of the lectin amount was remarkable. In contrast, the liposome of (3) was not particularly found to be aggregated.

From the above, it was confirmed that in the liposome of (1), the substance of the present invention was incorporated into the liposome membrane, and the galactose residue of lactose was exposed on the membrane surface.

Test 2 The liposome suspensions obtained in (1), (2) and (3) and the ³ H-inulin solution obtained in (4) were respectively
SD male rats (body weight 140-160g) intravenously weigh 1
0.5 ml was injected per 00 g. Thirty minutes later, the carotid artery was exsanguinated, the abdomen was opened, and the liver was removed. A portion of this was taken and homogenized in phosphate buffered saline. Next, the radioactivity was measured by the liquid scintillation method, and the recovery rate (%) with respect to the dose was determined. Radioactivity recovery in serum was calculated by observing rat whole blood as 6.5% of body weight and serum amount as 50% of whole blood. The results are shown in Table 1.

As is clear from Table-1, the distribution of liposomes containing the substance of the present invention in the liver was much larger than that in the control, and it was confirmed that the more the amount added, the greater the directivity to the liver.

Test 3 Using the suspensions of the liposomes obtained in (1) and (3), the inhibitory effect of asialofetuin having a galactose residue at the terminal and having hepatic parenchymal cell directivity was observed. That is, 1 minute before administration of the liposome suspension to rats under the same conditions as in Test 2, the phosphate buffered saline of asialofetuin was injected into the hind limb intravenously (the hind limb on the side opposite to the liposome injection side). After administration, the same operation as in Test 2 was performed thereafter.
The dose of asialofetuin is 1 per 100 g of rat body weight
It was 3.3 mg. The results are shown in Table 2.

As is clear from Table 2, the distribution of liposomes containing the substance of the present invention to the liver was significantly suppressed by pre-administration of asialofetuin. In contrast, the control liposomes were not affected by asialofetuin.

From the above, it was confirmed that the lipid film-forming body of the present invention has excellent directivity to hepatocytes.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Kikuchi 1-16-13 Kitakasai, Edogawa-ku, Tokyo Daiichi Pharmaceutical Research Institute

Claims (6)

[Claims] 1. The following formula (I): (In the formula, R represents a hydrogen atom or an acyl group, and COR ¹ is
Shows the fatty acid residue of C ₁₂ -C _30, Indicates an α or β bond. ) A lactose higher fatty acid derivative represented by: 2. The lactose higher fatty acid derivative according to claim 1, wherein COR ¹ is a C _{12 to} C ₂₂ fatty acid residue. 3. The lactose higher fatty acid derivative according to claim 1, wherein the acyl group is an acetyl group or a benzoyl group. 4. The lactose higher fatty acid derivative according to claim 1 or 2, wherein R is a hydrogen atom. 5. The lactose higher fatty acid derivative according to claim (1), wherein the lactose higher fatty acid derivative is 1-N-eicosanoyl-1-deoxy-β-lactosylamine. 6. The lactose higher fatty acid derivative is 1-N-eicosanoyl-1-deoxy-2,2 ', 3,3', 4 ', 6,6'.
-Leptose higher fatty acid derivative according to claim (1), which is -hepta-O-acetyl-β-lactosylamine.