JPH0440350B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a novel forskolin derivative having positive inotropic action, hypotensive action, and adenylate cyclase activating action. [Prior Art] Forskolin, which has a positive inotropic effect, a blood pressure lowering effect, and an adenylate cyclase activating effect, is already known [JP-A-52-79015, Drug Research, 31 1248 (1981). )]. [Problems to be Solved by the Invention] However, forskolin is poorly soluble in water, soluble in water at only 0.0026% at room temperature, and requires formulation innovation, so a water-soluble derivative is desired. [Means for Solving the Problems] Therefore, as a result of various studies, the present inventors determined that the general formula () (In the formula, R ¹ is a hydrogen atom, R ² is a 3-dimethylaminopropionyl group, R ³ is an acetyl group, and R ⁴ is a vinyl group). It has been found that it is neutral or basic, has higher water solubility than forskolin, and has positive inotropic effect, blood pressure lowering effect, and adenylate cyclase activating effect. The present invention was completed based on the above findings. The compound of the present invention can be obtained by using 7-deacetylforskolin as a raw material, converting the 7-position to 3-dimethylaminopropionylation, rearranging the group to the 6-position, and then acetylating the vacant 7-position. Specifically, it is as follows. (1) 3-dimethylaminopropionylation at position 7 can be obtained by the following three methods. (a) 7-deacetylphorscolin (R ¹ = R ²
= R ³ = H, R ⁴ = -CH=CH ₂ ) with the general formula () [In the formula, R ⁵ and R ⁶ are a methyl group and m
is 2. ] By condensing the compound represented by or its reactive derivative,

[In the formula, Y represents a halogen atom or an alkyl or arylsulfonyloxy group, and m is the same as above]

The compound represented by or its reactive derivative is condensed, and then the general formula () [In the formula, R ⁵ and R ⁶ are the same as above] By reacting the compound represented by

[In the formula, m' represents an integer of 2]

A compound represented by the above formula () or a reactive derivative thereof is condensed, and then a compound represented by the above general formula () is reacted. In the condensation of the above (a) to (c), general formulas (), (),
When using the carboxylic acid itself as the compound (), use dicyclohexylcarbodiimide, dicyclohexylcarbodiimide + 4-dimethylaminopyridine, carbonyldiimidozole, diphenylphosphoryl azide, etc. in a solvent such as benzene, chloroform, ether ethyl acetate, etc., for example. The condensation reaction is preferably carried out at a temperature of -20 DEG C. to 200 DEG C., usually under ice cooling, to around the boiling point of the solvent for 0.5 to 72 hours, preferably 2 to 48 hours, to give preferable results. Here, examples of the compound of general formula () include dimethylaminopropionic acid. An example of the compound of general formula () is chloropropionic acid. An example of the compound of general formula () is acrylic acid. In the condensation of the above (a) to (c), the general formula (),
When using reactive derivatives of (), (),
It can be obtained by reaction using a base such as pyridine or tolylethylamine in a solvent such as benzene, chloroform, ether, or ethyl acetate. The reaction takes place under ice cooling and around the boiling point of the solvent.
Doing it for an hour gives favorable results. Examples of the reactive derivative include acid halides, acid anhydrides, mixed acid anhydrides, and Roihi's anhydrides. In the production methods (b) and (c) above, the reaction with the amine of general formula () is carried out in a solvent such as dichloromethane by stirring for about 0.5 to 5 hours under ice cooling. Dimethylamine is an example of the amine represented by the general formula (). (2) Rearrangement reaction of the 3-dimethylaminopropionyl group at the 7-position to the 6-position The rearrangement reaction is performed using dimethyl sulfoxide, N,N
- in an organic solvent such as dimethylformamide, methanol, acetone, acetonyldioxane, tetrahydrofuran, etc., or in a mixed solvent of each solvent and water, preferably in a mixed solvent of N,N-dimethylformamide or acetonitrile and water, 0.1 to 10 equivalents, preferably 1
~3 equivalents of alkali metals, hydrides, carbonates, inorganic bases such as sodium hydroxide, potassium hydroxide, potassium carbonate, sodium hydride, or tri-lower alkylamines such as triethylamine, 1,8-diazabicyclo[ This is carried out by allowing an organic base such as 5,4,0]-7-undecene to act on forskolin substituted at the 7-position. The reaction is carried out at a temperature of approximately -20°C or approximately 200°C, usually under ice cooling or around the boiling point of the solvent for 1 minute or more.
It is carried out for 48 hours, preferably for 30 minutes to 1 hour at room temperature. Furthermore, it can also be obtained by treating the intermediate obtained in the condensation step of (b) or (c) of (1) above in the same manner as in (2) above, and then reacting it with the amine of the above formula (). I can do it. (3) Acetylation at the 7-position Acetic acid or a reactive derivative thereof is added to the 6-(-3dimethylaminopropionyl)-7-deacetylphorscolin obtained by the method (2) above as described in (1)-(a) above. The condensation may be carried out in the same manner as . In the above reaction, instead of the raw material 7-deacetylforskolin, etc., the 1-position hydroxyl group is substituted with an acyl group such as an acetyl group, an ether group such as a methyl ether group, or a silyl ether such as a t-butyldimethylsilyl ether group. The compound of the present invention of the general formula () can also be obtained by using a compound protected with a group or the like and removing the protecting group in the final step. Unless otherwise specified, the above reactions are preferably carried out in an organic solvent or a mixed solvent thereof with water. The compound of the present invention is purified and isolated from the reaction solution by a conventional method, and can be obtained as a free base, free acid, or salt depending on the reaction conditions and treatment method. The free bases can be individually converted into salts by conventional methods, if desired. Salts include inorganic acid salts such as hydrochloride, hydrobromide, sulfate, phosphate, or formate, acetate, fumarate, maleate, citrate, tartrate, lactate, It can be an organic acid salt such as methanesulfonate. In addition, among the compounds of the present invention, those having an asymmetric carbon in R ² or R ³ theoretically have optical isomers, so the present invention includes these optical isomers. . Optical isomers can be separated by known methods such as chromatography and fractional crystallization. [Action] Next, the action of the compound of the present invention will be explained. 1. Positive inotropic effect, blood pressure lowering effect A polyethylene tube was inserted into the left ventricle from the carotid artery to measure the left ventricular pressure in adult beagle or mongrel dogs, regardless of gender, under bentobarbital sodium anesthesia, and to measure blood pressure. Insert a polyethylene tube into the femoral artery. These polyethylene tubes are connected to a pressure transducer and continuously recorded on a recorder via a pressure strain gauge. Also, the rise rate of left ventricular pressure (dp/dt)
is obtained in differential form, recorded continuously in the same way, and used as an index of inotropic action. The drug effect is expressed as a relative value to the maximum response to each indicator of forskolin. That is, the maximum change in dp/dt increase and mean blood pressure (MBP) decrease when 30 μg/Kg of forskolin is intravenously administered is set as 1, and the test compound is
The maximum change when 300 μg/Kg or 30 μg/Kg was administered intravenously is expressed as a relative value. 2 Adenylate cyclase activating effect As an adenylate cyclase preparation, a membrane fraction obtained from a homogenate of guinea pig myocardium was used [GIDrummond.DLSeverson.L.
Duncan.J.Biol.Chem., 246.4166 (1971)]. Measurement was performed using the method of Salomon et al. [Y.Salomon.C.
Londos, M. Robdell, Anal.Biochem., 58.541
(1974)], labeled cAMP is produced by adenylate cyclase using labeled ATP as a substrate.
Measure. Reaction solution: 5mM MgCl ₂ , 20mM
Creatine phosphate, 100U/ml creatine phosphokinase, 1mM cAMP.1mM [ ¹⁴ C (U)]
25mM Tris containing ATP (approximately 7cpu/pmol) and forskolin or test compound (1μM).
Start the reaction by adding the enzyme preparation to a final volume of 100 μl with HCl (PH7.5). The amount of enzyme is 150 to 200 μg/100 μl of membrane protein.
After reacting at 37℃ for 10 minutes, add reaction stop solution (2%
Sodium dodecyl sulfate (SDS), 40mM
After adding 100 μl of ATP.1.4mM cAMP, PH7.5) to stop the reaction, add 50 μl of [ ³ H]cAMP (approximately 20,000 cpm) to determine the recovery rate of cAMP. After this, cAMP is separated using a Dowex50 resin column and a neutral Alumina column, and radioactivity is measured. The adenyl cyclase activating effect of the test compound (1 μM) is expressed as a percentage of the activating effect of forskolin (1 μM). [n=6, mean value ± standard error]. Next, regarding representative compounds of the present invention, 1.
The results of 2 are shown in Table 1.

〔effect〕

Such compounds of the present invention have excellent positive inotropic action, antihypertensive action, adenylate cyclase activating action, and better water solubility than forskolin. Therefore, the compound of the present invention is expected to be used as a therapeutic agent for acute or chronic heart failure, an antihypertensive agent, and a cerebral vasodilator. It is also expected to be used as a therapeutic agent for diseases caused by cAMP dysregulation, such as glaucoma, asthma, immunodeficiency disorders, tumors, and digestive system diseases. The dosage in this case varies depending on the patient's symptoms, age, and administration method, but is generally 0.01 to 30 mg/Kg/day. The compound of the present invention can be mixed with a suitable pharmaceutical carrier to form a preparation such as a tablet, granule, fine granule, powder, capsule, injection, suppository, eye drop, patch, ointment, etc., and can be administered orally. It is also administered parenterally. In particular, since it has better water solubility than forskolin, it can be made into a water-soluble preparation suitable for drip infusion or intravenous administration, so it is expected to have excellent therapeutic effects when administered parenterally. The compounds of the present invention will be described in more detail below with reference to Examples. Example 7-Deacetyl-7-(3-dimethylaminopropionyl)phorskolin. (1) 4-dimethylaminopyridine (3.00g), 3-dimethylaminopropionic acid hydrochloride (3.80g), and dicyclohexylcarbodiimide (7.00g) were added to a dichloromethane solution (60ml) of 7-deacetylphorskolin (2.00g). g) 3 in 47 hours
Add in portions and stir at room temperature. After the reaction is completed, the solvent is concentrated under reduced pressure, ethyl acetate is added to the resulting residue, and the mixture is filtered. The filtrate is concentrated and the resulting residue (6.05 g) is purified by silica gel chromatography. Elute with dichloromethane-methanol (20:1 to 10:1) to obtain 7-deacetyl-7-(3-dimethylaminopropionyl).
1.72 g of forskolin (68%) is obtained. mp 150-153℃ MS m/z (relative intensity): 467 (M ⁺ , 2). 202
(2). 159(8), 118(29), 92(61), 91(81),
58 (100). (2) 6-(3-dimethylaminopropionyl)-7
-Deacetylphorskolin 7-Deacetyl-7-(3-dimethylaminopropionyl)phorskolin (650 mg) was mixed with acetonitrile-water (4:1) in a mixed solvent (65
ml), added to 1N aqueous sodium hydroxide solution (2.78 ml), and stirred at room temperature for 1 hour. After the reaction is completed, the reaction solution is concentrated under reduced pressure. Water is added to the resulting residue and extracted with ethyl acetate. After washing the organic layer with water, it is dried over magnesium sulfate, and the desiccant is filtered off. The filtrate is concentrated under reduced pressure, and the resulting residue is purified by silica gel chromatography. By elution with acetonyl tolyl, 6-(3-dimethylaminopropionyl-7
-Deacetylphorskolin (566 mg, 87.1%)
get. Colorless oil MS m/z (relative intensity) 467 (M ⁺ ) (3) 6-(3-dimethylamino)propionylphorscholine 6-(3-dimethylamino)propionyl-
Pyridine (728 mg) and acetyl chloride (730 mg) were added in three portions to a mixture of 7-deacetyl phorskolin (566 mg) and dichloromethane (30 ml), and the mixture was stirred at room temperature overnight. After the reaction is completed, water is added, the mixture is made basic with a saturated aqueous sodium bicarbonate solution, and extracted with dichloromethane. The organic layer is dried with magnesium sulfate, and the desiccant is filtered off. The filtrate is concentrated and the resulting residue is purified by silica gel chromatography. Elute with chloroform-methanol (30:1), 6-
(3-dimethylamino)propioforscholine (194 mg, 32%) is obtained.

【table】

[41% from 1-(t-butyldimethylsilyl)-7-deacetylphorskolin]

Claims (1)

[Claims] 1. General formula (In the formula, R ¹ is a hydrogen atom, R ² is a 3-dimethylaminopropionyl group, R ³ is an acetyl group, and R ⁴ is a vinyl group.) A forskolin derivative and a physiologically acceptable salt thereof.