Optimization of the ultrasound-assisted synthesis of lutein disuccinate using uniform design

Process Intensification in Chemical Reaction Engineering

In the present review article, the definitions and the most advanced findings within Process Intensification are collected and discussed. The intention is to give the readers the basic concepts, fixing the syllabus, as well as some relevant application examples of a discipline that is well-established and considered a hot topic in the chemical reaction engineering field at present.

Process intensification and kinetic studies of ultrasound-assisted extraction of flavonoids from peanut shells

In this work, extraction of flavonoids from peanut shells has been studied in the presence of ultrasound and the results are compared with Soxhlet and heat reflux extraction for establishing the process intensification benefits. The process optimization for understanding the effects of operating parameters, such as ethanol concentration, particle size, solvent to solid ratio, extraction temperature, ultrasonic power and ultrasonic frequency, on the extraction of flavonoids has been investigated in details. The highest extraction yield (9.263 mg/g) of flavonoids was achieved in 80 min at optimum operating parameters of particle size of 0.285 mm, solvent to solid ratio of 40 ml/g, extraction temperature of 55 °C, ultrasonic power of 120 W and ultrasonic frequency of 45 kHz with 70% ethanol as the solvent. Two kinetic models (i.e. phenomenological model and Peleg's model) have been introduced to describe the extraction kinetic of flavonoids by fitting experimental data and predict kinetic parameters. Good performance with slight loss of goodness of fit of two models was found by comparing their coefficient of determination (R2), root mean square error (RMSE) and/or mean percentage error (MPE) values. This work would provide the reduction of degradation and the economic evaluation for the extraction processes of flavonoids from peanut shells, as well as give a better explanation for the mechanism of ultrasound.

Power ultrasound and its applications: A state-of-the-art review

Ultrasonic processing has attracted increasing attention by people because ultrasonic technology may represent a flexible 'green' alternative for energy efficient processes. The major challenges for the power ultrasound application in real situations are the design and development of specific power ultrasonic systems for large-scale operations. Thus, new families of power ultrasonic transducers have been developed in recent years to meet actual needs, and this contributes to the implementation of power ultrasound of application in many fields such as chemical industry, food industry and manufacturing. This paper presents the current state of ultrasonic transducers of magnetostrictiv type and piezoelectric type as well as applications of power ultrasound in various industrial fields including chemical reactions, drying/dehydration, welding, extraction, heat transfer enhancement, de-ice, enhanced oil recovery, droplet atomization, cleaning and fine particle removal. The review paper helps to understand the current development of power ultrasonic technology and its applications in various situations, and induce extended applications of power ultrasound to more and more fields.

Synthesis of lutein esters using a novel biocatalyst of Candida antarctica lipase B covalently immobilized on functionalized graphitic carbon nitride nanosheets

Lutein scavenges free radicals and inhibits vision damage caused by photo oxidation, while decomposing easily with light and heat. Its stability and bioavailability can be tremendously improved by lutein ester synthesis. However, green and efficient esterification preparation methods are urgently needed. In this study, which used functionalized graphitic carbon nitride nanosheets (g-C₃N₄-Ns) as the immobilized carrier, a novel biocatalyst was designed and prepared to accommodate Candida antarctica lipase B (CALB), considerably enhancing the performance. It was characterized by TEM, XRD, FTIR, XPS, TGA, and BET to demonstrate successful preparation and then applied to catalyze esterification between lutein and succinate anhydride in dimethyl formamide (DMF) solvent resulting in a conversion rate up to 92% at 50 °C in 60 h, 34% more than free CALB under the same conditions. We believe this is the highest esterification rate in lutein esters synthesis and it has great potential to facilitate eco-friendly and efficient preparation.

Synthesis, characteristics and evaluation of antioxidant activity of [1-(tannin-ether)-ethyl]stearate

The [1-(tannin-ether)-ethyl]stearate (TEES) was synthesized by two-stage process successfully. 1-Chloroethyl tannin ether (CTE), as an intermediate, was initially prepared with tannic acid (TA) and paraldehyde. Then, the TEES was synthesized by sodium stearate and CTE in the presence of FeCl3-PEG-400 as phase-transfer catalyst. Synthetic conditions were optimized. The structural characteristics of TEES were analyzed by FTIR, 1H NMR and UV-vis techniques. And the thermal stability of TEES was investigated. Moreover, the antioxidant activity of TEES for linseed oil was evaluated and compared with other substance such as TA and butylated hydroxyanisole (BHA). The results showed that the yield reached 88.19 wt% (theoretical value: 88.80 wt%, relative deviation: 0.80 ± 0.34%) under the optimized condition, in which the ratio of TA: FeCl3: PEG-400 was 1 g: 0.09 g: 0.693 mL, the reaction temperature and time was 75 °C and 240 min, respectively. The antioxidant activity of TEES was higher than TA and comparable to BHA in linseed oil. The POV of oil samples with TEES, TA and BHA were 63.4, 201.3 and 84.2 meq/kg after 20 days, respectively. The reason of this was relate to the better oil solubility of TEES and its unique structure. More importantly, the interaction between the TEES and SC was weaker than that of TA and SC by the fluorescence experiment.

A review of engineering aspects of intensification of chemical synthesis using ultrasound

Cavitation generated using ultrasound can enhance the rates of several chemical reactions giving better selectivity based on the physical and chemical effects. The present review focuses on overview of the different reactions that can be intensified using ultrasound followed by the discussion on the chemical kinetics for ultrasound assisted reactions, engineering aspects related to reactor designs and effect of operating parameters on the degree of intensification obtained for chemical synthesis. The cavitational effects in terms of magnitudes of collapse temperatures and collapse pressure, number of free radicals generated and extent of turbulence are strongly dependent on the operating parameters such as ultrasonic power, frequency, duty cycle, temperature as well as physicochemical parameters of liquid medium which controls the inception of cavitation. Guidelines have been presented for the optimum selection based on the critical analysis of the existing literature so that maximum process intensification benefits can be obtained. Different reactor designs have also been analyzed with guidelines for efficient scale up of the sonochemical reactor, which would be dependent on the type of reaction, controlling mechanism of reaction, catalyst and activation energy requirements. Overall, it has been established that sonochemistry offers considerable potential for green and sustainable processing and efficient scale up procedures are required so as to harness the effects at actual commercial level.

Enhanced oral bioavailability of acetylpuerarin by poly(lactide-co-glycolide) nanoparticles optimized using uniform design combined with response surface methodology

Acetylpuerarin (AP), an acetylated derivative of puerarin, shows brain-protective effects in animals. However, AP has low oral bioavailability because of its poor water solubility. The objective of this study was to design and develop poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) to enhance the oral bioavailability of AP. The NPs were prepared using a solvent diffusion method optimized via uniform design (UD) combined with response surface methodology (RSM) and characterized by their morphology, particle size, zeta (ζ)-potential, encapsulation efficiency (EE), drug loading (DL), and in vitro drug release. A pharmacokinetic study was conducted in Wistar rats administered a single oral dose of 30 mg/kg AP. The optimized NPs were spherical and uniform in shape, with an average particle size of 145.0 nm, a polydispersity index (PI) of 0.153, and a ζ-potential of −14.81 mV. The release of AP from the PLGA NPs showed an initial burst release followed by a sustained release, following Higuchi’s model. The EE and DL determined in the experiments were 90.51% and 17.07%, respectively. The area under the plasma concentration-time curve (AUC_0−∞) of AP-PLGA-NPs was 6,175.66±350.31 h ng/mL, which was 2.75 times greater than that obtained from an AP suspension. This study showed that PLGA NPs can significantly enhance the oral bioavailability of AP.

Three statistical experimental designs for enhancing yield of active compounds from herbal medicines and anti-motion sickness bioactivity

BACKGROUND

Since antiquity, Zingiber officinale (ginger), pogostemonis herba, and radix aucklandiae have been used as traditional Chinese medicines to remit gastrointestinal discomfort. Recent evidences also show the efficacy of the three herbal medicines against nausea and vomiting.

OBJECTIVE

To optimize the CO2 supercritical fluid extraction (SFE-CO2) conditions for ginger and the ethanol reflux extraction conditions for radix aucklandiae, control the quality of pogostemonis herba essential oil, and evaluate anti-motion sickness activity of the compound recipes composed of the three herbal medicine extracts.

MATERIALS AND METHODS

Two orthogonal array designs L9 (3)(4) were employed to optimize the SFE-CO2 conditions for enhancing yield of 6-gingerol from ginger and the ethanol reflux extraction conditions for enhancing yield of costunolide and dehydrocostus lactone from radix aucklandiae; a uniform design U5(5(3)) was applied for evaluation of anti-motion sickness activity of the compound recipes.

RESULTS

Extraction pressure (P < 0.01), extraction temperature and extraction time (P < 0.05) have significant effects on the yield of 6-gingerol from ginger by SFE-CO2; ethanol concentration (P < 0.01) and times of repeating extraction (P < 0.05) have significant effects on the total yield of costunolide and dehydrocostus lactone from radix aucklandiae by ethanol reflux extraction; the anti-motion sickness effects of the optimized compound recipe composed of the three herbal medicine extracts were markedly better than those of dimenhydrinate.

CONCLUSION

The compound recipe composed of ginger, pogostemonis herba, and radix aucklandiae could be developed as a promising anti-motion sickness medicine.

Optimization of ultrasonic frequency for the improvement of extraction yields of bufadienolides from the Chinese medicine ChanSu by using a novel ultrasonic system

Optimization of ultrasonic frequency for the improvement of extraction yields of bufadienolides was evaluated successfully using an online extraction system.

A facile strategy to recycle template P123 from mesoporous aluminosilicates by ultrasonic extraction

High synthesis cost of mesoporous aluminosilicates (MA) limits their practical application. Recycling of copolymer template employed in preparation of MA is an effective way to reduce the synthesis cost. An ultrasonic extraction strategy for recycling of organic template P123 in MAs is reported. Effects of different extraction parameters on P123 recovery are investigated and the optimum conditions are obtained. 75.0% P123 is recovered from MAs within 10 min by one-step ultrasonication. Characterizations indicated that the resulting P123-free MA (MA-U) exhibits excellent properties compared with that of calcined products. Moreover, recovered P123 can be employed to synthesize high hydrothermally stable MA. This investigation provides a facile strategy to recycle P123 from MA.