SE445643B - CYCLIC ACETALS, PROCEDURES FOR THEIR PREPARATION AND CYTOSTATIC, ANALGETIC AND / OR HYPOTENSIVE COMPOSITION CONTAINING THESE ACETALS - Google Patents

Description

7905330-2 10 '15 20 25 30 2 US-PS 2,927,05l + indicates condensation of certain sugars, e.g. glucose, mannose, fructose, etc., with an aldehyde or ketone to form cyclic acetals of the sugar. The mechanism apparently involves the elimination of water by combining the oxygen in the carboxyl group of the aldehyde or ketone with the hydrogen from each of the two hydroxyl groups of the sugar. This condensation reaction proceeds upon heating the mixture to the boiling point of the aldehyde in the presence of an acid acetalization catalyst, conditions which favor the open chain form of the sugar. The two adjacent carbon atoms in the cyclic acetal ring are adjacent carbon atoms of the aliphatic chain of the sugar molecule. Several such cyclic acetal rings can be formed on the same sugar molecule, so that poly (cyclic acetals) are formed.

An object of the present invention is to provide novel compounds with cytostatic, hypotensive and analgesic action.

Another object of the invention is to provide novel compositions effective in the treatment of cancer and hypertension, as well as in pain relief as well as with other utility such as antitumor agents in humans and animals.

Yet another object is to provide a process for the preparation of the novel compounds discussed herein.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description.

The description of the invention is made with reference to the accompanying drawings, in which Figure 1 is a nuclear magnetic resonance spectrum (NMR) for pure methylglyoxal; Figure 2 is an NMR spectrum of deuterium oxide solvated methylglyoxal; Figure 3 is an NMR spectrum of the product (in acetone-DG) from the reaction between L-ascorbic acid and methylglyoxal; Figure 11 'is an NMR spectrum of the product of Example 3; and Figure 5 is an IR spectrum of the product of Example 3.

The novel cyclic acetals of the invention are represented by the formula 7905550-2 3 where R 1 is 11 H-Å-on c = o cn cn) l ('1, || or || X where X is hydrogen, methyl or phenyl.

The invention further relates to the hydrated or dehydrated forms of the above-mentioned novel compounds. The new cyclic acetals of formula I are prepared by mixing approximately equal amounts of an aldehyde or a ketone of the general formula R1 \\ C ___ 0 II R "" // 2 where R or X X-II (II-H 1 XC = 0 1 X where X is hydrogen, methyl or phenyl, and L-ascorbic acid and allows them to react preferably under a nitrogen atmosphere at about room temperature in aqueous media. In this case the reactant of the formula 11 is purified methylglyoxal, the reaction is indicated by a reduction in the reducing nature of L-ascorbic acid with iodine to about 5% of its original value.The purified reaction product is obtained by evaporation in vacuo followed by column chromatography or azeotropic distillation. called AM.

It should be noted that purified methylglyoxal may be replaced by commercially available methylglyoxal, with or without polymerization inhibitors, which may contain hydrated or oligomeric methylglyoxal. Nuclear Magnetic Resonance (NMlU spectra were obtained for pure methylglyoxal (Fig. 1), deuterium oxide solvated methylglyoxal (Fig. 2), and AM monohydrate (Fig. 3).., .. w. "- ... a ... An infrared (IR) spectrum for AM monohydrate was also obtained, the NMR spectrum showed two different methyl proton resonances, one expected for a methyl ketone (at 52.2) and a second which can be attributed to a hydrated methyl ketone (in §1, 8) Comparing Figures 2 and 3, it is noted that the absorption due to the aldehyde proton of methylglyoxal appears to have shifted to the acetal region (§ß, 0- 4 ', 5) integration indicates a 1: 1 (or 4: 4) ratio between the total number of CH protons of L-ascorbic acid and the total number of CH protons of methylglyoxal.

From these data it can be concluded that the enolic hydroxyl groups (in positions 2 and 3) of ascorbic acid react with the aldehyde carboxyl group of methylglyoxal to form a cyclic acetal as follows: 0 67 C49 Ho-c / H \ / c = o + Ho- c o -> Hac-ccH | \ / i \ o o-c \\, / ”H-% O _ 0 + H20 | Cï CH. 1 H (L H0 0 ... 3 “° 't“: so (Eat-H CHQÛH U H0-en on H °' C "H 2 (ta on AB 2 The ketonic carbonyl group in structure A undergoes hydration (in a to the extent of about 9096) to form the product of structure B. The invention is not limited to any particular reaction mechanism, by reaction between methylglyoxal monohydrate and L-ascorbic acid, or between methylglyoxal and L-ascorbic acid, which product is then hydrated.

Elemental analysis of the product (AM) gave C, 4359196; H: 5.93%; 0.51, 1696 (0 determined indirectly). C 9 H 15 O 5 requires C, 415596; H, 4.84%; 0.51.61%. Similar NMR and IR analyzes were performed on compounds prepared from other aldehydes or ketones intended for the invention instead of methylglyoxal, and on compounds prepared from other endiol compounds instead of L-ascorbic acid.

In all such cases, the NMR and IR spectra were consistent with the product being a cyclic acetal.

It should be noted that it is surprising and unexpected that the reactions of the present invention proceed in aqueous solution. It is generally known and expected in this field of organic chemistry that acetalization and ketalization reactions take place in anhydrous media. In addition, it is unexpected that the aldehydes and ketones discussed herein react selectively with the LB-hydroxyl groups of L-ascorbic acid, since "all known acetals of L-ascorbic acid are formed with the 5,6-hydroxyl groups.

The reaction may proceed. After purification and sterilization, the composition is administered to animals harboring cancer cells. After administration, the cancer cells stop dividing and further tumor development is stopped. Patients also experience a general loss of pain and a decrease in blood pressure.

Example 1 100 grams of L-ascorbic acid were dissolved in 400 ml of oxygen-free distilled water in a nitrogen atmosphere. 205 ml of methyl glyoxal (# 0 96-g aqueous solution, available from Aldrich Chemical Co., Inc., Milwaukee, Wisconsin) was added to the L-ascorbic acid solution, and the mixture was allowed to stand at room temperature under a nitrogen atmosphere for about 1 hour. After purging the evaporator with nitrogen, the mixture was evaporated to constant weight at room temperature to a light yellow sticky mass to give 130 grams. This product was deposited ck evenly on thin layer chromatographic plates fi of cellulose and placed in a chamber containing the ethyl acetate benzene (2: 3) as solvent. Methylglyoxal rose with the solvent front.

The product had an Ri value of about 0.3 and the ascorbic acid did not migrate.

When titrated with iodine solution, the product showed the presence of 5% ascorbic acid or its equivalent reducing substance. Example 2 1.52 grams (0.01 mol) of phenylglyoxal monohydrate was added to a solution of 1.76 grams (0.0l mol) of L-ascorbic acid in 50 ml of water and kept under stirring in a nitrogen atmosphere for 1 hour, after which it was evaporated to dryness in vacuo. (Alternatively, it can be lyophilized.) The product was isolated as in Example 1. The NMR spectrum of the main product showed absorption around 6,150-155, which is characteristic of acetyl C-H. The IR spectrum showed two different carbonyl groups, one in a lactone and another in an arylcarbonyl group. About 5096 iodine was consumed during titration, indicating partial reaction of the free endiol group.

Example 2 2-Methyl-2,5-dimethoxy-Zβ-dihydrofuran (2,5-dimethoxy-Z, 5-dihydrosylvan) - which is the cyclic mixed acetal of 1-oxopent-Z-enal - was synthesized as described by Clauson. Kaas and Limborg (Clauson-Kaas, N., and F. Limborg, _f _ \ _ c_t¿ Chem. Scand., L: 6l9 (1947)). 10 grams of this material was added to an aqueous solution of L-ascorbic acid (5 grams / ZS ml of water) under a nitrogen atmosphere. A light yellow solution was obtained after 10 minutes. Water was removed by vacuum evaporation overnight at room temperature. No iodine was consumed during titration, indicating that the 2,3-hydroxyl groups of L-ascorbic acid reacted. The crude product showed two spots (Rf 0.65 and 0.3) on silica gel thin layer chromatographic plates using chloroform-methanol (9zl) as solvent. __. v ”__- q- .... -.-» - ~ - .m - va 7905550-2 10 '15 20 25 '30 3.5 ExemEl 4 A 60 megaherts NMR spectrum (Figure 4) i acetone-de indicated the presence of O- Hfhç-H (vinyl), HC <(acetal) and CH 2 - (methylcarbonyl) protons in addition signals for the C f, C 5 and C α protons of L-ascorbic acid. et (in nujol soil; Fig. 5) indicated the presence of several hydroxyl groups and two different carbonyl groups.

Using the same experimental techniques as in Example 2, 5.6 grams (0.1 mol) of acrolein was added to an aqueous solution (20 ml) of 20 grams of L-ascorbic acid. As soon as the oily acrolein disappeared, a colorless precipitate of the monoacetal precipitated. It was filtered off and characterized in the usual way as the 2,3-monoacetal of L-ascorbic acid with acrolein.

Example 5 The yellow product obtained as described in Example 1 was dissolved in a small amount of ethyl acetate-benzene (2: 3) and applied to a chromatography column containing adsorbent material in the form of DEAE-cellulose (diethylaminoethylcellulose). A narrow band of the yellow product slowly migrated down the column as ethyl acetate-benzene (2: 3) solvent was allowed to pass through the column. The product was collected in a small filtrate volume.

Example 6 The yellow product obtained as described in Example I was dissolved in a small amount of ethyl acetate and adsorbed on Celite (siliceous or diatomaceous earth) and dried. The dried CelitgPD powder was washed with chloroform to eliminate excess methylglyoxal. The product was then removed from the Celite material eluting with ethyl acetate.

Example 7 In 13 grams of the yellow product obtained as described in Example 1 was dissolved in 200 ml of ethyl acetate, and the solvent was evaporated at room temperature. Excess methylglyoxal was eliminated as an azeotropic mixture. (Alternatively, ethyl acetate may be replaced by chloroform or water). Methylglyoxal in ethyl acetate was determined by precipitation as the ZJ1-dinitrophenylhydrazone and * was found to be about 896.

Further studies of the product after purification by the methods of Example 5 or 6 followed by evaporation showed: a) that the product is hygroscopic and tends to form an amorphous mass; (b) that the product contains 558% ascorbic acid (on the basis of iodine consumption) and (c) that, in reaction with excess lil-dinitrophenylhydrazine, 2,4-. _...-._.._-. > -......_ a ..., _._.._.... l0 15 20 25 30 35 7905330-2 the dinitrophenylhydrazone of methylglyoxal is formed over a period of 4-5 days.

Determination of 2,11-dinitrophenylhydrazones suggests a 1: 1 molar combination of L-ascorbic acid and methylglyoxal i product.

Example 8 The procedures of Examples 1 and 5 were followed using freshly distilled methylglyoxal. The product after chromatographic purification consisted of a colorless white powder which was less hygroscopic than the product of Example 5.

Example 9 0.25 ml of a 2.5 96 g aqueous solution of the product of Example 6 was administered intraperitoneally (i.p.) twice daily to Swiss albino mice (25 grams each). No toxic symptoms were observed.

A single injection per day of 0.25 ml of a 5.0 96 g aqueous solution of the product of Example 7 caused weight loss, diarrhea and eventually death.

Example 10 Swiss albino mice (25 grams each) were injected with 11 x 10 6 cells of Ehrlich carcinoma. Another 20 animals were similarly injected with 1: x 106 Sarcoma 180 cells. The following day: half of the animals received two injections (i.p.) of 0.25 ml of a 2.5 96 g aqueous solution of the product of Example 7.

The injections were repeated daily. On the eighth day, the animals were sacrificed, and the peritoneal cavity of each was washed with 20 ml of saline (0.996). The washing solutions were combined and centrifuged, and the volume of the sediment was measured. This sediment contained the collected malignant cells. Table I shows the results of summing the cell volumes obtained from the peritoneal cavities of 20 mice. No weight loss or toxic symptoms were observed except for light peritoneal haemorrhage in treated animals.

Table I Injected cells Untreated Treat_cl_e_ Ehrlich carcinoma 1.274 '0.14 "Sarcoma l80" 1.46 ^ 0.05 + Total volumes of cells collected, milliliters.

Example Seven patients with advanced stages of various cancers were treated by oral administration of 250 mg four times a day in orange juice or by intravenous (iv) administration of 1 mg AM / ml 0.9 96 saline to achieve a total daily dose. pâ lg; complete clinical examination was performed prior to administration. Constant observation with pulse, temperature and blood pressure control was maintained throughout the infusion period. Routine biochemistry, hematology, liver function tests, urinalysis, blood glucose, serum enzymes and blood proteins were performed as needed before, during and after administration of the drug.

Inch ears were measured where possible by palpation, X-rays and photography.

PATIENT A Female, age 40 Histological diagnosis: Undifferentiated carcinoma of the (right) kidney with mEfBSfñSef.

Previous treatment: Adriamycin, cyclophosphamide, vincristine, j-fluorouracil, steroids, warfarin sodium. Three courses given with partial remission after the first and second courses only.

Status at the beginning of AM therapy: Patient very ill, dyspnotic, cough, abdominal and chest pain, abdominal tumor fixed (H) l2 x 8 cm.

Virchow's gland 4 x 2 cm fixed, sore lesions on the upper part of the head Dose: l x I and l x 2 cm, X-ray - pulmonary secondary. 1 gram (g) i.v. over 24 hours day 0; l g i.v. over 24 hours day 2; 1 g orally over 24 hours on days 4, 5 and 8; l g i.v. over 24 hours day 15 to 21 - continued.

Result: Significant clinical improvement in respiration within 12 hours.

Painless within 24 hours. Virchow's gland free from deep structure within 48 hours. inflammation around the gland is absent. Head lesions dry and covered with crust (during healing), no surrounding inflammation. Blood pressure dropped steadily from an initial value of 130190 to 75/50 day 3. Hemoglobin dropped from 12.5 g to 9.0 g during the first 24 hours. Signs of congestive heart failure with ankle and sacral edema. The lungs are sluggish in the bases. No dyspnoea - slowly improved when i.v. therapy ~ n-ceased. Blood donated units. Abdøminai distans-mn oehfaiarïkéæsag 15. 1.v _.'_ 1_ = 6rjade pa nytt. No improvement in the first Ziller hours, then gradual recovery over the following 24 hours. Painless and breathed freely. The abdominal distension decreased, the diarrhea ceased. i.v. continued. Virchow's gland again free from deep tissue fixed to the skin. Abdominal tumor 10 x 6 cm. Lung X-ray no change in tumor size but sharper contour.

Biochemistry and hematology: Abnormalities in hydroxybutyrate dehydrogenase, alkaline phosphatase, serum albumin, blood sugar. l0 15 20 25 7905330-2 PATIENT B Female, age 56 Histological diagnosis: Adenocarcinoma of the colon with liver metastases.

Previous treatment: Surgical resection, colostomy. fi-fluorouracil, levamisole, cyproheptadine, warfarin sodium.

Status at the beginning of AM therapy The patient is deeply yellowish, ill, vomits.

Liver 5 cm below the costal edge, hard and nodular. Ascites - bilateral pleural effusion. Hepatic function tests abnormal.

Dose: Oral 1 gram in 24 hours.

Result: Vomiting ceased, otherwise no change. Acute congestive heart failure after 48 hours - death. No change in hemoglobin levels.

Biochemistry and hematology: Abnormalities in bilirubin, aspartate transaminase, alanine transaminase, alkaline phosphatase, white blood cell count.

PATIENT C Female, age 46 Histological diagnosis: Interductal breast cancer. Stage IV.

Bone metastases.

Previous treatment: Cyclic combination chemotherapy with cyclophosphamide, S-fluorouracil, adriamycin and methotrexate. Deep X-ray therapy for spinal secondary. RF hyperthermia.

Status at the beginning of AM therapy: Liver and bone metastases. Severe pain.

Relieved with morphine.

Dosage: 1 g i.v. over 24 hours day 0 and 2.

Result: Painless six hours after the start of the infusion. Recurrence of pain for 12 hours after completion of infusion on day 0. Repeated infusion again gave a pain-free period for 21+ hours after infusion. No toxic effects.

No effect on hemoglobin.

Biocernia and hematology: Abnormalities in the rate of blood segregation. 10 li 20 7905330-2 '10 PATIENT D Female, age 14-3 Histological diagnosis: Advanced undifferentiated breast carcinoma with multiple metastases.

Previous treatment: Deep X-ray therapy. Cyclic chemotherapy. Warfarin- sodium. RF hyperthermia.

Status at the beginning of AM therapy: Bone, lung and liver secondary. Back pain and dyspnea. Wounded lesions on the chest wall 5 x 6 cm and 2 x 2 cm.

Dosage: 1 g i.v. in six hours day 0 and day 7.

Results: Relief of pain and dyspnea. No analgesics were required after day 0. No effect on visible tumor. Extremely tired. Blood pressure dropped from iso / SO in 100160 day o. Day 1 was now repressed iso / so. Föu again day 7, 130/90 to 100/70.

Biochemistry and hematology: Abnormalities in hydroxybutyrate dehydrogenase, lactic acid dehydrogenase.

PATIENT E Female, age 40 Histological diagnosis: Recurrent melanoma. Metastatic.

Previous treatment: B.C.G. levamisole, D.'I'.I.C. surgical excision - block dissection. RF hyperthermia.

Status at the beginning of AM therapy: Large partial necrotic lesion ll! x 10 cm in (V) groin with exhaustive sinus l00 + ml dailyPain.

Dose: 1 g over six hours day 0. 1 g over six hours day 5. 1 g over six hours day 9.

Result: Painless at the end of the first infusion. Emptying from the sinus stopped at the end of the infusion on day 0. No change in tumor size, but the skin infusion slowed down. The pain returned on days 7 and 8.

Vomiting after infusion day 5. Extreme fatigue day 6 to day 9.

Blood pressure stable.

Biochemistry and hematology: Abnormalities in: blood creatinine, aspartate transaminase, alanine transaminase, hydroxybutyrate dehydrogenase, lactate dehydrogenase, alkaline phosphatase.

PATIENT F Female, age 53 Histological diagnosis: Adenocarcinoma of the breast with brain metastases. Returned mande.

Previous treatment: Surgical resection of brain metastases. Cobalt ray therapy. Cyclic combined chemotherapy.

Status at the beginning of AM therapy: Miserable with headache and vomiting due to increased intercranial pressure. Papilloedema, multiple spinal metastases. Pain.

Dosage: 1 g i.v. over 214 hours day 0, 1, 2, 3, li, 5, 6, 7, continuously.

Result: Vomiting ceased on day 2. The pain subsided but was present during rotational movement in the lumbar region. Papillary edema decreased. Headache gone day 5. No side effects. Patient alert and cheerful day 7.

Blood pressure was maintained.

Biochemistry and hematology: Abnormalities in: alkaline phosphatase, serum albumin.

PATIENT G Male, age 73 Histological diagnosis: Scaly cell carcinoma of the lung, inoperable. Chronic bronchitis and emphysema.

Previous treatment: Radiofrequency hyperthermia. _ ..._ .. «.._._.__.-_.... 10 15 25 7905330-2 l2 a Status at the beginning of AM therapy: Karnofsky 0 deteriorated. Severe dyspnoea.

Chest pain relieved by analgesics.

Dosage: 1 g i.v. for 24 hours.

Result: nothing but relief of chest pain for 24 hours.

The patient continued to deteriorate and died on day 3. Hemoglobin levels stable.

Biochemistry and hematology: Abnormalities in: white blood cell count, blood sedimentation rate, blood urea, serum sodium, serum chloride, serum calcium, aspartate transaminase, alanine transaminase, alkaline phosphatase.

The above clinical studies establish that AM is useful in the treatment of various cancers. Continuous intravenous administration inhibits tumor activity and leads to a general regression of the disease. In addition, the compounds of the invention have utility in relieving hypertension and pain.

It is known that the rapid proliferation of cancer cells leads to the accumulation of toxic products in tissues surrounding the tumor and throughout the body. It has been speculated that these toxic products are responsible for the general pain associated with the many forms of cancer. The general pain relief experienced by patients in clinical trials with the drugs of the invention may be due to the cessation of the production of these toxic metabolites.

The mode of action of the compounds of the invention with respect to cytostatic, hypotensive and analgesic effects is unclear at this time. However, the empirical observation that cells stop proliferating when exposed to these compounds is sufficient to justify their use in the treatment of such serious, hitherto incurable, and often fatal diseases, such as cancer. In addition, once the efficacy of these drugs has been established and their safety established, they can serve as effective agents in relieving hypertension and pain. "_ .___ .____...., _-.-.-.- :.

Claims (1)

A compound of the formula O á C 121 o _ c \ \ C / n 0 / \ 'g O - C HO-ç-H CH2OH where RI is l' I HÖ- l-ÛH C = QC __ HX, 1, H or XC - H 1 X and X are hydrogen, methyl or phenyl. Compound according to Claim 1, characterized in that S is = O CHB 3. Compound according to Claim 1, characterized in that Ho-e-on x wherein X has the meaning given in Claim 1. åš-O-Gï fi ä ll l O: lå: E 4. A process for the preparation of a compound according to any one of the claims of 7905330-2 lll 1. -3, k ä n n e t e c k n a t of reacting an aldehyde or ketone with the formula thereRlär l l ¶ | ï = 0 fi "H or fi- HX 'cH ca I. | XC = O 1 X i and X are hydrogen, methyl or phenyl, or a functional derivative thereof, with L-ascorbic acid. A process according to claim 4, characterized in that the reaction is carried out under an atmospheric atmosphere in aqueous medium 6. Process according to claim 4 or 5, characterized in that the aldehyde is methylglyoxal.10 Cytostatic, analgesic and / or hypotensive composition, characterized in that that it contains as active ingredient a compound according to any one of claims 1 to 3. A composition according to claim 7, characterized in that said compound is dissolved in about 10 to 10,000% by weight, based on the weight of the compound, 0.996 μg saline or water.