A Green Synthesis Strategy of Binuclear Catalyst for the C-C Cross-Coupling Reactions in the Aqueous Medium: Hiyama and Suzuki–Miyaura Reactions as Case Studies

Cellulose, as a green and available phytochemical, was immobilized on the surface of magnetite nanoparticles then doped with imidazole and Co. complex (Fe3O4@CNF ∼ ImSBL ∼ Co.) and used as a water-dispersible, recyclable and efficient nano catalyst for the synthesis of C−C cross-coupling reactions including fluoride-free Hiyama and Suzuki reactions in an aqueous medium as an efficient and vital solvent, due to their high application and importance in various fields of science. Different spectroscopic and microscopic techniques were used for the catalyst characterization such XRD, FESEM, TEM, FT-IR, EDX, DLS, VSM, UV-Vis, and ICP analyses. The presence of imidazole as ionic section tags with hydrophilic character on the Co-complex supported on magnetic nanoparticles provides dispersion of the catalyst particles in water, which leads to both higher catalytic performance and also facile catalyst recovery and reuse six times by successive extraction and final magnetic separation. High catalytic activity was found for the catalyst and high to excellent efficiency was obtained for all Suzuki (80–98% yield; E factor: 1.1–1.9) and Hiyama (87–98% yield; E factor: 0.26–1.1) derivatives in short reaction times under mild reaction conditions in the absence of any hazardous or expensive materials. There is not any noticeable by-product found whether for Suzuki or Hiyama derivatives, which reflects the high selectivity and also the lower the E factor the more favorable is the process in view of green chemistry. The bi-aryls were achieved from the reaction of various aryl iodides/bromides and even chlorides as the highly challenging substrates, which are more available and cheaper, with triethoxyphenylsilane or phenylboronic acid. To prove the performance of the catalyst components (synergistic of SBL ∼ Co. and IL), its different homologs were incorporated individually and studied for a model reaction. Exclusively, this is an introductory statement on the use of Cobalt binuclear symmetric ionic liquid catalysts in Hiyama reactions.

Detection of Reclaimed Asphalt Pavement Presence in Asphalt Mixtures Using a Method of Successive Asphalt Binder Extraction

The work deals with the detection of presence of RAP (reclaimed asphalt pavement) in asphalt mixtures. Information about the presence of RAP in an asphalt layer can be technically advantageous, for example, when planning further recycling of the layer. The method described in the paper can also be used to verify the success of a treatment of an aged binder in RAP, which is dosed in the production of new asphalt mixtures. The asphalt binder was obtained by a method of successive extraction from asphalt mixtures with different RAP content. Basic empirical tests of the asphalt binder (needle penetration and softening point) were chosen to detect the presence of RAP. The complex shear modulus G* was further determined on the extracted binders using a dynamic shear rheometer (DSR).

Phytochemical Screening, GC-MS Analysis and Biological Activities of Extracts of Artemisia vulgaris Linn.

The aerial parts of Artemisia vulgaris were subjected for successive extraction in solvents methanol, hexane and chloroform, respectively, and compounds present in extract were analysed by GC-MS analysis 12 different compounds were found in chloroform extract in which Germacrene was found most abundantly (33.84%). Chloroform extract showed strong antibacterial activity, which was examined against 6 bacteria using the disc diffusion method. The IC50 value of chloroform extract accounted for 1.50 mg/mL. The TPC content of the extract was found to be 87.75 mg gallic acid equivalent/g of dry extract, whereas TFC content was found to be 47.25 mg quercetin equivalent/g of dry extract and exhibited LC50 value of 0.18 mg/mL.

Phytochemical screening and antimicrobial activity of Haematostaphis barteri

The aim of this work was to carry out the phytochemical screening and antimicrobial activities of Haematostaphis barteri. The method of cold maceration was used in the extraction by serial exhaustive extraction method which involves successive extraction with solvents of increasing polarity from a non-polar (hexane) to a more polar solvent (methanol) to ensure that a wide polarity range of compound could be extracted. The results showed that flavonoids, terpenes, terpenes, tannins, and saponins are present in all the leaf extracts. The result of the antimicrobial activity obtained from the extracts of the leaf of Haematostaphis barteri revealed that all the crude extracts of the leaf inhibited or exhibited antibacterial activity against Salmonella paratyphi, Staphylococcus aureus, Escherichia coli, and Penicillium spp. All the extracts did demonstrate antimicrobial activity against Aspergillus niger. The plant H. barteri is commonly used traditionally for the treatment of diarrhoea, wound, headache, malaria, dysentery and fevers. The overall results confirm the significance of the use of the plant in traditional medicinal treatment of diarrhea, wound, headache, malaria, dysentery and fevers, in line with reported claims.

Potential for the valorisation of brewer’s spent grains: A case study for the sequential extraction of saccharides and lignin

This study highlights the possibility of using brewers’ grains (BSGs) for the successive extraction of the main lignocellulosic biopolymers, namely, cellulose, hemicelluloses and lignin. An exhaustive chemical characterisation revealed a variability of composition in distinct batches of BSGs, depending on their origin and the brewing process used. In particular, the protein content can vary from 13wt% to 23wt%, which is accompanied by a change in the hemicelluloses content from 9% to 23% (in the samples of our study). By applying a two-step aqueous treatment, involving an acid (1.25% v/v aq. H2SO4) and a base (3% w/v aq. NaOH) at a temperature of 120°C and fixed reaction time of a few tens of minutes (15–90 minutes), more than 80% of hemicelluloses could be recovered. Cellulose could be isolated at more than 68%, while a high purity lignin could be recovered from a lignin-rich fraction (70wt%). Our work also suggests that the variability of the chemical composition of these BSGs is a hindrance to achieving process standardisation and large-scale exploitation. The pooling of various materials is therefore not a recommended option, and the preliminary chemical analysis of the composition is therefore a prerequisite for an efficient extraction process.

PHYTOCHEMICAL STUDIES OF STAR FRUIT AVERRHOA CARAMBOLA L.

The paper deals with a phytochemical investigation on the fruit of Averrhoa carambola L. belonging to the family Oxalidaceae. Commonly known as “star fruit”. Fruits and leaves are used widely in Ayurveda preparations to pacify impaired Kapha, pitta, skin diseases, pruritis, worm infestations, diarrhea, vomiting, hemorrhoids, intermittent fever, over-perspiration, and general debility. In the present study fruits of Averrhoa carambola L. were screened for their phytochemical constituents following hot continuous and successive extraction by Soxhlet apparatus. A qualitative assay was done using a range of solvents. The extraction process was carried using different solvents successively in the order of increasing polarity. Qualitative analysis of the extracts using standard procedures revealed the presence of alkaloids, avonoids, tannins, saponins, glycosides, steroids&terpenoids, phenols, coumarins, and phytosterols. Preliminary screening of phytochemicals is a valuable step, in the detection of the bioactive principles present in medicinal plants and subsequently, may lead to drug discovery and development.

New Estimation of Antibiotic Resistance Genes in Sediment Along the Haihe River and Bohai Bay in China: A Comparison Between Single and Successive DNA Extraction Methods

Sediment is thought to be a vital reservoir for antibiotic resistance genes (ARGs). Often, studies describing and comparing ARGs and their potential hosts in sediment are based on single DNA extractions. To date, however, no study has been conducted to assess the influence of DNA extraction efficiency on ARGs in sediment. To determine whether the abundance of ARGs is underestimated, we performed five successive extraction cycles with a widely used commercial kit in 10 sediment samples collected from the Haihe River and Bohai Bay. Our results showed that accumulated DNA yields after five extractions were 1.8–3.1 times higher than that by single DNA extractions. High-throughput sequencing showed that insufficient DNA extraction could generate PCR bias and skew community structure characterization in sediment. The relative abundances of some pathogenic bacteria, such as Enterobacteriales, Lactobacillales, and Streptomycetales, were significantly different between single and successive DNA extraction samples. In addition, real-time fluorescent quantitative PCR (qPCR) showed that ARGs, intI1, and 16S rRNA gene abundance strongly increased with increasing extraction cycles. Among the measured ARGs, sulfonamide resistance genes and multidrug resistance genes were dominant subtypes in the study region. Nevertheless, different subtypes of ARGs did not respond equally to the additional extraction cycles; some continued to have linear growth trends, and some tended to level off. Additionally, more correlations between ARGs and bacterial communities were observed in the successive DNA extraction samples than in the single DNA extraction samples. It is suggested that 3–4 additional extraction cycles are required in future studies when extracting DNA from sediment samples. Taken together, our results highlight that performing successive DNA extractions on sediment samples optimizes the extractable DNA yield and can lead to a better picture of the abundance of ARGs and their potential hosts in sediments.

Green Extraction Strategies for Sea Urchin Waste Valorization

Commonly known as “purple sea urchin,” Paracentrotus lividus occurs in the Mediterranean Sea and the eastern Atlantic Ocean. This species is a highly appreciated food resource and Italy is the main consumer among the European countries. Gonads are the edible part of the animal but they represent only a small fraction (10–30%) of the entire sea urchin mass, therefore, the majority ends up as waste. Recently, an innovative methodology was successfully developed to obtain high-value collagen from sea urchin by-products to be used for tissue engineering. However, tissues used for the collagen extraction are still a small portion of the sea urchin waste (<20%) and the remaining part, mainly the carbonate-rich test and spines, are discarded. Residual cell tissues, tests, and spines contain polyunsaturated fatty acids, carotenoids, and a class of small polyphenols, called polyhydroxynaphthoquinones (PHNQ). PHNQ, due to their polyhydroxylated quinonoid nature, show remarkable pharmacologic effects, and have high economic significance and widespread application in several cosmetic and pharmaceuticals applications. A green extraction strategy aimed to obtain compounds of interest from the wastes of sea urchins was developed. The core strategy was the supercritical CO2 technique, characterized by low environmental impacts. Fatty acids and carotenoids were successfully and selectively extracted and identified depending on the physical parameters of the supercritical CO2 extraction. Finally, the exhausted powder was extracted by solvent-based procedures to yield PHNQ. The presence of Spinochrome A and Spinochrome B was confirmed and extracts were characterized by a remarkably high antioxidant activity, measured through the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. Overall, the selective and successive extraction methods were validated for the valorization of waste from sea urchins, demonstrating the feasibility of the techniques targeting added-value compounds.

Catechin Extracted from Uncaria gambier Roxb for Nanocatechin Production: Physical and Chemical Properties

This research reports nanoparticles or nanocatechin produced from catechin extracted from gambier and the differences between the properties of the extracted catechin and nanocatechin. The study began with the preparation of >95% pure catechin through successive extraction. The catechin obtained was converted to nanocatechin with a high-speed homogenizer on a 1% suspension of catechin in water at 12,000 rpm for 30, 45, 60, 75 or 90 minutes. Results showed average diameters of the nanocatechin 90-minute homogenized colloids were then dried with a spray dryer so physical and chemical properties could be compared with those of the raw extracted catechin. Catechin content, water content, pH, refractive index, density, molecular weight and rotational angle were unaltered. Appearance, solubility, thermal properties, highest absorbance wavelength and antioxidant activity were measured. Initial degradation temperature and antioxidant activity of nanocatechin were higher than those in the originally extracted catechin.

Phytochemical Screening of Decoction and Ethanolic Extract of Amomum dealbatum Roxb. Leaves

Renggak (Amomum dealbatum Roxb.) is a species from the genus Amomum widely spread in Lombok. Traditionally, Amomum dealbatum Roxb. (renggak) is an antiseptic to treat rheumatism and arthritis. However, there was limited report of its phytochemical contents and biological activity of Amomum dealbatum Roxb. This study is preliminary research that aims to determine the phytochemical content of Amomum dealbatum Roxb. leaf decoction and its ethanolic extract. For this study, we used two different extraction methods. The fully powdered plant used for the successive extraction in the cold process for maceration methods was 800 g, and ethanols were used as solvents. We used a traditional receipt that utilized three fresh leaves in the decoction methods with 4,5 L of water as solvents. Phytochemical screening was carried out qualitatively by using the tube method with specific reagents for each compound. Important phytochemicals that were screened are flavonoids, alkaloids, tannins, saponins, steroids, and triterpenoids. Phytochemical screening from plant extract and decoction revealed the presence of flavonoids, alkaloids, and tannins. Triterpenoid was only detected on the extract, and none of the extract and decoction have saponins and steroids. Our finding provides information about secondary metabolites that present in Amomum dealbatum Roxb. These phytochemical findings are essential and might be useful as quality parameters and to predicts its biological activities.