scholarly journals Effect of Microwave-Assisted Aqueous Two-Phase Extraction of α-Solanine from S. retroflexum and Analysis on UHPLC-qTOF-MS

Author(s):  
Tebogo Mphatlalala Mokgehle ◽  
Ntakadzeni Madala ◽  
Wilson Mugera Gitari ◽  
Nikita Tawanda Tavengwa

Abstract A new, fast and efficient method, hyphenated microwave-assisted aqueous two-phase extraction (MA-ATPE) was applied in the extraction of α-solanine from Solanum retroflexum. This environmentally friendly extraction method applied water and ethanol as extraction solvents. Central composite design (CCD) was performed which included numerical parameters such as time, mass of plant powder and microwave power. The categorical factors included the chaotrope — NaCl or the kosmotrope — Na2CO3. Fitting the central composite design response surface model to the data generated a quadratic model with a good fit (R2 = 0.920). The statistically significant (p < 0.05) parameters such as time and mass of plant powder were influential in the extraction of α-solanine. Quantification of α-solanine was achieved using a robust and sensitive feature of the ultra-high performance quadrupole time of flight mass spectrometer (UHPLC-qTOF-MS), multiple reaction monitoring (MRM). The optimized condition for the extraction of α-solanine in the presence of NaCl and Na2CO3 was a period of 1 min at a mass of 1.2 g using a microwave power of 40%. Maximal extraction of α-solanine was 93.50 mg kg−1 and 72.16 mg kg−1 for Na2CO3 and NaCl, respectively. The synergistic effect of salting-out and microwave extraction was influential in extraction of α-solanine. Furthermore, the higher negative charge density of the kosmotrope (Na2CO3) was responsible for its greater extraction of α-solanine than chaotrope (NaCl). The shorter optimal extraction times of MA-ATPE make it a potential technique that could meet market demand as it is a quick, green and efficient method for removal of toxic metabolites in nutraceuticals.

2021 ◽  
Author(s):  
Tebogo Mokgehle ◽  
Ntakadzeni Madala ◽  
Wilson Gitari ◽  
Nikita Tavengwa

Abstract Aqueous two phase extraction (ATPE) was applied in the extraction of an allelochemical, solasodine, from an invasive plant, Solanum mauritianum. Central composite design was performed which included numerical parameters such as time and mass of plant powder. The categorical factors included the type of salt used in aiding extraction such as the chaotrope (NaCl) and kosmotrope (Na2CO3). Fitting the central composite design response surface model to the experimental data generated a quadratic model with a good fit (R2 = 0.925). The linear effect of mass of plant powder was a statistically significant (p < 0.05) parameter for solasodine extraction. The optimized conditions for the extraction of solasodine in the presence of NaCl or Na2CO3 were time: 10 min and mass of plant powder: 1.2 g. Corresponding to these conditions, the maximal mean extraction based on multiple reaction monitoring (MRM) transition of solasodine (m/z 414 → 396) on the UHPLC-qTOF-MS was 233.65 mg kg-1 and 413.50 mg kg-1 for NaCl and Na2CO3, respectively. The greater extraction ability of the kosmotrope was due to the higher negative charge density of the carbonate ion during salting-out. Furthermore, the synergistic effect of mass of plant powder and salting-out was shown to enhance extraction of solasodine compared to the chaotrope. The kosmotrope assisted solasodine ATPE extracts from Solanum mauritianum, can potentially be applied as antipathogenic agents in medicine while simultaneously limiting the allelopathic impact of Solanum mauritianum.


Author(s):  
Tebogo Mphatlalala Mokgehle ◽  
Ntakadzeni Edwin Madala ◽  
Wilson Mugera Gitari ◽  
Nikita Tawanda Tavengwa

AbstractThe biomass Solanum mauritianum (S. mauritianum) is an invasive weed specie; however, it is a source of medicinally important metabolites, as reported in literature, such as solasonine and solamargine. The study was directed at the optimization of microwave and aqueous two-phase-based extraction techniques which involved microwave-assisted extraction (MAE), aqueous two-phase extraction followed by microwave-assisted extraction (ATPE + MAE), and the “one-pot” microwave-assisted aqueous two-phase extraction (MA-ATPE) for extraction of solasonine and solamargine from leaves of S. mauritianum which was evaluated. The microwave-assisted extraction of solasonine and solamargine yielded optimums at 5.00 min, microwave power of 270 W, and solid/liquid of 0.1 g L−1 at an ethanol concentration of 60%. Application of a two-stage extraction (MAE + ATPE) in CaO-dried alcohol resulted in decreased amounts of solasonine and solamargine extracted. The best yields of solasonine and solamargine were achieved in the MA-ATPE method. Extraction of solamargine and solasonine using Na2CO3 in CaO-dried ethanol during MA-ATPE was approximately threefold and twofold greater than that of MAE + ATPE, respectively. Furthermore, extraction of solamargine and solasonine using NaCl in CaO-dried ethanol during MA-ATPE was approximately twofold greater than that of MAE + ATPE. The synergy of microwaves and salting-out in the “one-pot” MA-ATPE technique was shown to be a contributing factor for enhanced extraction of solamargine and solasonine from leaves of S. mauritianum. Application of this time- and energy-efficient extraction method could potentially be expanded for enrichment of medicinally important compounds from biomass of other medicinal plants.


Sign in / Sign up

Export Citation Format

Share Document