Optimization of Solvent-Free Microwave-Assisted Hydrodiffusion and Gravity Extraction of Morus nigra L. Fruits Maximizing Polyphenols, Sugar Content, and Biological Activities Using Central Composite Design

Black mulberry, Morus nigra L. (family: Moraceae), is a healthy food and medicinal plant. Microwave hydrodiffusion and gravity (MHG) is one of the most innovative applications of solvent-free microwave extraction. The aim of this study was to optimize for the first time the MHG solvent-free extraction of polyphenols and sugars from M. nigra fruits. Optimization was carried out using a central composite design (CCD) with selected responses such as extraction yield, total polyphenol (TPC), flavonoid (TFC), anthocyanin (TAC), and sugar (TSC) contents, in addition to DPPH radical scavenging, and α-glucosidase (AGHi), lipase (Li), and xanthine oxidase (XOi) inhibition as tools to evaluate the best parameters for efficient and rapid extraction of black mulberry. The optimized extract was characterized in terms of the aforementioned parameters to validate the models, and was further analyzed for 36 individual polyphenols using HPLC-MS/MS. The optimized MHG extract was finally compared with traditional extracts, and demonstrated much better performance in terms of TPC, TAC, and Li, while the traditional extracts showed better XOi and AGHi. In conclusion, MHG is a valuable green technique for the production of non-degraded black mulberry polyphenol-rich extract and we suggest its larger use in the pharmaceutical and food industries.

Natural and Semisynthetic Triterpenes from Combretum leprosum Mart. with Antiplasmodial Activity

Malaria is responsible for thousands of deaths each year. Currently, artemisinin combination therapy (ACT) is used as first-choice medication against the disease. However, the emergence of resistant strains prompts the search for alternative compounds. The present study aimed to investigate the antiplasmodial activities of natural triterpenes (compounds 1 and 2), and semisynthetic derivatives 1a, 1b, 1c, and 1d. Antiplasmodial assays were carried out using the SYBR Green technique, whereas cytotoxicity was evaluated by the MTT (3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide) method. Hemolytic assays were performed on human erythrocytes. An in silico analysis of the compounds against PfENR (Plasmodium falciparum 2-trans-enoyl-reductase) was carried out by molecular docking. Experiments with 1, and its derivatives against P. falciparum showed that 1a was very similar in terms of biological activity to compound 1 (half maximal inhibitory concentration (IC50) ca. 4 μM), whereas 1b, 1c, and 1d had reduced antiplasmodial activities (IC50 between 8-103 μM). The selectivity indexes of 1 and 1d for HepG2, and Vero cells were > 10. Docking results partially agreed with the in vitro experiments, with 1 and 1c having the best and worst affinities with PfENR, respectively. In conclusion, the results showed that 1 and 1d may serve as biotechnological tools in the development of antimalarial drugs.

An Effect of pH on Radiation Assisted Modification of Oxygen-Rich Activated Carbon by Urea

Activated carbons (ACs) are a versatile group of adsorbents for water pollution control, especially organic dyes. Harsh chemicals and high temperatures are required for the activation process of ACs, which becomes a significant concern due to their toxicity and harmful effects on human health and the environment. Gamma irradiation, an alternative green technique, is a promising strategy for pretreatment and escalates the nitrogen or oxygen functional group of ACs. The current study provides the modification of ACs by the gamma irradiation in the various pH (5-11) of urea solution. The modified ACs were characterized by scanning electron microscopy (SEM), nitrogen gas adsorption-desorption analysts (BET), temperature program desorption (TPD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray diffraction spectroscopy (XRD). The point of zero charges and dye adsorption capacities were determined. This finding demonstrates that the ACs can be modified by gamma irradiation at 25 kGy in the urea solution media. The degree of graphitization enhanced significantly at pH 11(AC-pH11). The oxygen-rich functional groups created by radiation assists could enhance the electrostatic attraction between acid gases or cationic dyes. AC-pH11 also was able to adsorb methylene blue (160.73 ± 1.70 mg/g) greater than methyl orange (127.57 ± 2.22 mg/g).

DYNAMIC ANALYSIS OF SUSTAINABLE PRACTICES ADOPTION IN ROAD INFRASTRUCTURE DEVELOPMENT

Awareness of the importance of sustainable development has made many governments prioritize the adoption of green measures. The road infrastructure sector is no stranger to this and has been transforming its processes in such a way that they incorporate more sustainable practices. However, the inclusion of this type of practice has not been an easy task, since the adoption of these practices results from a decision-making process that is affected by the context of potential adopters, as well as other external parameters such as institutional, environmental, socioeconomic factors, etc. This study aims to identify the main variables that affect the adoption of sustainable practices in the development of roadways in Colombia. Through the application of the Bass Diffusion model concept, the most influential variables were identified and a Causal Loop Diagram (CLD) was built to understand the dynamics and feedback processes between them. External variables such as the popularity of the green technique, guidelines existence, and costs associated with them are significantly influential in the inclusion of green measures. Additionally, the level of influence of each variable is assessed through the formulation of a system dynamics model and the evaluation of different scenarios. Finally, a set of recommendations to overcome barriers in the process of green measures adoption is given. This model can be used as a support tool in formulating strategies that promote sustainable practices in road development.

Development of Biochars Derived from Water Bamboo (Zizania latifolia) Shoot Husks Using Pyrolysis and Ultrasound-Assisted Pyrolysis for the Treatment of Reactive Black 5 (RB5) in Wastewater

Adsorbent made by carbonization of biomass under oxygen-limited conditions has become a promising material for wastewater treatment owing to its cost-effective, simple, and eco-friendly processing method. Ultrasound is considered a green technique to modify carbon materials because it uses water as the solvent. In this study, a comparison of Reactive Black 5 (RB5) adsorption capacity between biochar (BC) generated by pyrolysis of water bamboo (Zizania latifolia) husks at 600 °C and ultrasound-assisted biochar (UBC) produced by pyrolysis at 600 °C assisted by ultrasonic irradiation was performed. UBC showed a greater reaction rate and reached about 80% removal efficiency after 4 h, while it took 24 h for BC to reach that level. Scanning electron microscope (SEM) images indicated that the UBC morphology surface was more porous, with the structure of the combination of denser mesopores enhancing physiochemical properties of UBC. By Brunauer, Emmett, and Teller (BET), the specific surface areas of adsorbent materials were analyzed, and the surface areas of BC and UBC were 56.296 m2/g and 141.213 m2/g, respectively. Moreover, the pore volume of UBC was 0.039 cm3/g, which was higher than that of BC at 0.013 cm3/g. The adsorption isotherms and kinetics revealed the better fits of reactions to Langmuir isotherm and pseudo-second-order kinetic model, indicating the inclination towards monolayer adsorption and chemisorption of RB5 on water bamboo husk-based UBC.

Combination of a Green and a Traditional Method for Estimating Relative and Absolute Ink Age: A Case Study of Ballpoint Pen Ink Dating in Vietnam

The dating of ink in questioned documents remains a significant challenge in forensic investigations in Vietnam and other countries. Many forensic examination methods have been usually applied to ensure the highest accuracy of the assessment results while maintaining high environment awareness. In this study, paper characteristics were physically tested to confirm source similarity, and the relative ink dating was established by high-performance thin-layer chromatography (HPTLC). Absolute ink dating by solvent and dye identification was performed by Raman spectrometry—a green technique, using a time-dependent degradation model for crystal violet and the comparison between 2-phenoxyethanol peak intensities. We found that the relative dating of the questioned document was 14 ± 3 months lesser than that of the reference samples, i.e., the absolute age of the questioned samples was estimated to be 24 ± 3 months. The combination of the conventional HPTLC method with the dynamic crystal violet degradation Raman model provides promising results for relative and absolute ink dating of ballpoint pens, which can be applied for documents written 1–15 years prior to the time of examination. The combination of the abovementioned methods demonstrated an acceptable error margin, affording highly practical applications in modern forensic science.

Microwave assisted synthesis of some azo disperse dyes part 2: Eco-friendly dyeing of polyester fabrics by using microwave irradiation

This study aimed to use microwave irradiation as a green technique, not only to enhance the dyeing efficiency of disperse-colored polyester fabrics, but also to conserve resources and minimize the environmental effects. Arylazopyrazolopyrimidinones dyes 1-9 were applied to polyester fabrics at 2% shade using conventional method and microwave at 100 °C. Both the color intensity expressed as dye absorption and the fastness characteristics of the dyed fabric were investigated. The K/S values are increased by increasing the time of irradiation from 10-60 minutes. The dyed substrate displayed good light fastness, and very good fastness levels to rubbing, perspiration washing, and sublimation, respectively.

The Art of Total Synthesis of Bioactive Natural Products via Microwaves

: Natural products are the most effective source of potential drug leads. The total synthesis of bioactive natural products plays a crucial role to confirm the hypothetical complex structure of natural products in the laboratory. The total synthesis of rare bioactive natural products is one of the great challenges for the organic synthetic community due to their complex structures, biochemical specificity, and stubborn stereochemistry. Subsequently, the total synthesis is a long process in several cases and it requires a substantial amount of time. Microwave irradiation has emerged as a greener tool in organic methodologies to reduce reaction times from days and hours to minutes and seconds. Moreover, this non-classical methodology increases product yields and purities, improves reproducibility, modifications of selectivity, simplification of work-up methods, and reduces unwanted side reactions. Such beneficial qualities have stimulated this review to cover the application of microwave irradiation in the field of the total synthesis of bioactive natural products for the first time during the last decade. An overview of the use of microwave irradiation, natural sources, structures, and biological activities of secondary metabolites is presented elegantly, focusing on the involvement of at least one or more steps by microwave irradiation as a green technique.