WO2010057503A2

WO2010057503A2 - Long acting conserved natural functional groups curcumin

Info

Publication number: WO2010057503A2
Application number: PCT/EG2008/000044
Authority: WO
Inventors: El-Sayed Ameen Mahmoud Rezq; Mohammad Talaat Abdel-Aziz Mansour; Taha Abdullah Kumosani
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-11-20
Filing date: 2008-11-20
Publication date: 2010-05-27
Anticipated expiration: 2011-05-20
Also published as: EP2365956A4; EP2365956A2; WO2010057503A3

Abstract

Curcumin is a component of turmeric, a yellow spice from the rhizome of the herb Curcuma longa L. (Zingiberaceae), that is widely used as a food flavoring and coloring agent. Curcumin has a long history of medicinal use for a wide variety of medical conditions. It is insoluble in water but soluble in ethanol, alkalis, glacial acetic acid and chloroform. Oral administration is well tolerated, but bioavailability is very low. Long acting, conserved natural functional group curcumin, of free water solubility, easy digestibility, free intestinal absorption, long serum half-life should help getting the utmost possible beneficial effects of this historical, albeit promising treatment of several acute and chronic illnesses. Natural pure water insoluble curcumin has been converted to a novel, water soluble conserved natural functional group derivatives, with no change to its original active functional natural molecular chemical groups necessary for full biochemical, physiological and pharmacological potencies previously reported for natural curcumin. The novel curcumin derivatives were characterized by IR Spectroscopy, GC/MS, NMR, EM, TLC, Gel Filtration, Continuous Flow Electrophoresis and Isoelectric Focusing whenever applicable. Laboratory animal studies of the novel curcumin derivatives proved that they conserved all the natural curcumin functionality in addition to the novel free water solubility, easy digestibility, free intestinal absorption, long serum half-life besides improved original biochemical, physiological and pharmacological potencies of natural curcumin towards certain pre-studied effects in humans and experimental animal models e.g. erectile dysfunction, diabetes mellitus.

Description

LONG ACTING CONSERVED NATURAL FUNCTIONAL GROUPS CURCUMIN

Technical Field

This invention relates to the synthesis of a novel curcumin-protein conjugate with conserved natural functional groups necessary for curcumin biochemical, physiological and pharmacological functionality. It also relates to the novel intermediate essential for the synthesis of the abovementioned curcumin-protein conjugate.

In addition, the novel derivatives relate to conveying lacking essential properties on natural curcumin such as; free water solubility, easy digestibility, free intestinal absorption, long serum half-life and improved original biochemical, physiological and pharmacological potencies of natural curcumin towards certain pre-studied effects in humans and experimental animal models.

Such novel derivatives with their improved properties are intended to be used in medical studies in experimental animal models to try to get better medicinal effects that were not achievable with natural curcumin.

Background Art

Curcumin, l,7-Bis(4-hydroxy-3-methoxyphenyl)-l,6-heptadiene-3,5-dione is a component of turmeric, a yellow spice from the rhizome of the herb Curcuma longa L. (Zingiberaceae), that is widely used as a food flavoring and coloring agent. Curcumin has a long history of medicinal use for a wide variety of medical conditions. It is insoluble in water but soluble in ethanol, alkalis, glacial acetic acid and chloroform.

Oral administration is well tolerated, but bioavailability is very low. However, when curcumin is used as a supplement, it is absorbed quickly but does not stay in the body for long. The cells lining of the intestine are equipped with enzymes that convert curcumin into other substances, and also with molecular pumps that pump curcumin and its byproducts out of the intestinal lining back into the intestine. Less than 1% of the curcumin actually makes its way to the bloodstream, where the liver rapidly destroys most of it. To counteract this problem, Bioperine which is a unique blend from black and long pepper was used as an additive. It enhances the absorption of curcumin in the body. But for people who have medical conditions, or who are taking other supplements or drugs, all kinds of risks are elevated as such substances are known to interact with various drugs used to treat several medical conditions.

In general three different approaches were used to improve cuecumin bioavailability; namely: additives, microemulsions and chemical derivatives, but none proved to overcome the problem. Additives as Piperine, (from black pepper), Quercetin (from various plants), Genistein (from soy) were used with the aim to inhibit the natural pumps that expel curcumin out of the intestinal and/or other cells. Microemulsions, e.g. natural oils such as peppermint oil, different surfactants such as lecithin, monoolein, Tween-20 were used with the aim to facilitate intestinal curcumin absorption in larger amounts. Chemical derivatives e.g., tetrahydro curcumin, demethoxy curcumin, tetrahydrodemethoxy curcumin, bisdemethoxy curcumin, tetrahydro bisdemethoxy curcumin, hexahydrocurcumin, acetate, phosphate, gluconate, ..., etc. were used with the aim to avoid the abovementioned action of the intestinal enzymes/pumps and liver enzymes. But all such chemical derivatives were made through the use of the curcumin natural functional groups required for full biological activity, (biochemical, physiological and pharmacological potencies).

Long acting, conserved natural functional group curcumin, of free water solubility, easy digestibility, free intestinal absorption, long serum half-life should help getting the utmost possible beneficial effects of this historical, albeit promising treatment of several acute and chronic illnesses.

Disclosure of Invention

Curcumin, l,7-bis(4-hydroxy-3-methoxyphenyl)-l,6-heptadiene-3,5-dione (I), was coupled to diazotized 4-aminobenzoic acid for the synthesis of the novel compound 1 ,7-bis(5-carboxyphenylazo-4-hydroxy-3 -methoxyphenyl)- 1 ,6-heptadiene-3 ,5 -dione (II), which in turn was utilized for the synthesis of the novel curcumin-bovine serum albumin conjugate (III), through the use of l-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluene sulfonate. Both compounds (II) and (III) represent the novel embodiment of this invention. ^

Nitrous acid was generated by the addition of a solution of 0.85 niEq of sodium nitrite to an excess of HCl. The reaction was maintained at a temperature of 5°C. A solution of 0.85 niEq of 4-aniinobenzoic acid in IN HCl chilled to 5⁰C was prepared with continuous stirring in ice bath for 20 minutes, the pH of 1.0 was never exceeded. Diazotized 4-minobenzoic acid was added dropwise to an equivalent concentration, (0.85 mEq) of curcumin, (I) dissolved in ethanol at pH 11.0 with continuous stirring at 5⁰C. The solution was acidified to pH 2.0 at which derivative (II) l,7-bis(5- carboxyphenylazo-4-hydroxy-3 -methoxyphenyl)- 1 ,6-heptadiene-3 ,5 -dione was precipitated. The precipitate was centrifuged and redissolved in ethanol at pH 11.0 again. After repeating the acid and base cycle twice, the crude derivative (II) was chromatographed on a column of silica gel. Reduced pressure evaporation of the elution solvent gave a derivative of about 98% purity as checked by TLC. The curcumin-bovine serum albumin conjugate (III), of this invention was synthesized in a medium of 1% NaCl/dioxane/NaOH solution of pH 8-10, at 5⁰C, by adding 0.1M solution of l-cyclohexyl-3-(2-morpholinoethyl) carbodiimide metho-p-toluene sulfonate to purified crystalline l,7-bis(5-carboxyphenylazo-4-hydroxy-3- methoxyphenyl)-l,6-heptadiene-3,5-dione, (II) in the same medium with continuous stirring. Bovine serum albumin was added to the foregoing mixture at 5⁰C, pH 8-10 with continuous stirring for 1 hr until the intermediate azopseudourea has conjugated to bovine serum albumin, after which the mixture was centrifuged off, acidified to pH 4.2, salted out, recentrifuged, redissolved then dialyzed for 24 hr at 5⁰C against 0.5M sodium carbonate, pH 8.2 until any color no longer appears in dialysis solution. A final dialysis is performed against bi-distilled water for 24 hours at 5°C, after which the protein conjugate (III) was lyophilized. The novel curcumin derivatives (II) and (III) were characterized by IR Spectroscopy, GC/MS, NMR, EM, TLC, Gel Filtration, Continuous Flow Electrophoresis and Isoelectric Focusing whenever applicable.

Claims

We claim; the synthesis of long acting, conserved natural functional group curcumin derivatives, of. free water solubility, easy digestibility, free intestinal absorption, higher bioavailability and longer serum half-life for the utmost possible beneficial effects in treatment of several previously reported acute and chronic illnesses treated with curcumin.

This invention relates specifically to the synthesis of a novel conserved natural functional group curcumin-protein conjugate, conserving the essential original biochemical, physiological and pharmacological potencies of natural curcumin towards certain pre-studied effects in humans and experimental animal models.

The invention also relates to a novel intermediate essential for the preparation of the abovementioned compound as well as the use of the claimed derivatives in medical studies in experimental animals for treatment from some acute and chronic illnesses e.g. erectile dysfunction, diabetes mellitus and all other illnesses reported to be treated or benefited from natural curcumin treatment.

Natural pure water insoluble curcumin has been converted to a novel, water soluble conserved natural functional group derivatives, with no change to its original active functional natural molecular chemical groups necessary for full biochemical, physiological and pharmacological potencies previously reported for natural curcumin. The novel curcumin derivatives were characterized by IR Spectroscopy, GC/MS, NMR, EM, TLC, Gel Filtration, Continuous Flow Electrophoresis and Isoelectric Focusing whenever applicable.

Laboratory animal studies of the novel curcumin derivatives proved that they conserved all the natural curcumin functionality in addition to the novel free water solubility, easy digestibility, free intestinal absorption, long serum half-life besides improved original biochemical, physiological and pharmacological potencies of natural curcumin towards certain pre-studied effects in humans and experimental animal models e.g. erectile dysfunction, diabetes mellitus.