Kinetic and Thermodynamic Behavior of Extraction of Oleoresin Containing Curcuminoids from Turmeric (Curcuma longa L.) in Acetone and Their Bioavailability
Authors: Kunyima A. B. , Kuburhanwa J. C. , Kaseya H. M. , Kunyima M. B. 
Published: November 2022

Background: Why this miraculous and amphiphilic compound, the curcumin, which has a very extraordinary therapeutic potential (because can react with many targets in the organism), has a weak bioavailability in the organism and is metabolized in compounds having very weak activity or inactive compounds?. How to improve substantially its bioavailability and therefore its absorption in the organism in order to allow its incorporation in making of pharmaceuticals regardless of its nanoparticles of which obtention is furthermore hardworking?

Aim: It seems indicated to search the response in the kinetic and thermodynamic behavior of this compound or in its co-administration with the other compounds in vitro in order to understand how to increase its absorption in vivo because bioavailability entails hydrosolubility (hydrophile) of curcuminoids of which the molecules are naturally hydrophobes.

Objective: So our objective is to make better our understanding of the absorption of natural curcuminoids in the organism without resorting to chemical transformation in nanoparticles that is additionally hardworking.

Methodology: In this paper, kinetic and thermodynamic study of extraction of oleoresin containing curcuminoids from Turmeric (Curcuma Longa L.), using KUNYIMA’s first law, has been performed in acetone that can be reduced in propan-2-ol which is water-like solvent by catalytic hydrogenating (H2,Ni ) or by chemical reduction (LiAlH4).

Results: The weak global kinetic constant of extraction of oleoresin containing curcuminoids has been determined at 250 rpm (round per minute) and found the same at 500 rpm (k= 0.1520 ± 0.0005) min-1 for temperature of 27,5°C and constant pressure in acetone in closed system.

Conclusion: Kunyima’s first law has made possible the kinetic and thermodynamic study of extraction of oleoresin containing curcuminoids from Turmeric. Kinetic constant is a measure of solubility of oleoresin containing curcuminoids and therefore a measure of solubility of curcuminoids in a given solvent, ethanol and acetone being concerned in this paper as solvents. Results show that kinetic constant is inversely proportional to solubility of solvent and it can be a parameter abling the determination of the endothermic or exothermic behavior of extraction of curcuminoids. The endothermic behavior of curcuminoids hereby determined in ethanol and acetone in vitro, increased by magnetic stirring, suggests their weak bioavailability and therefore the weak bioavailability of curcumin. The challenge of this actual research is to improve our understanding of kinetics and thermodynamics of extraction of oleoresin containing curcuminoids from Turmeric in vitro in order to presage their bioavailability still weak for an efficient validated action. The increase of bioavailability will be done whether through improved formulations of curcumin or through new pathways of administration. The conception of curcumin analogous is also a way to promote its effects. More the phenomenon is exothermic in water-like solvents, more the involved chemical compound is bioavailable.

The study revealed the predominance of keto form of curcumin in acetone and the lack of bioavailability of curcumin (curcuminoids) through the endothermic behavior of extraction of oleoresin containing curcuminoids and through the weak global kinetic constant.

The variation of entropy in acetone has shown without surprise the disturbance of the system after extraction.

The values of kinetic constants in acetone and ethanol as water-like solvents have been compared and showed the great solubility of curcuminoids in acetone evidenced by the weak kinetic constant compared to that in ethanol.

Curcumin predicts anyway hopeful future.