Background Rumex nepalensis, a widely known traditional medicinal plant and is used as the source of medicines and human diet in various communities. Currently, the phytochemical investigation and pharmacological studies of R. nepalensis are of significant research interest. Therefore, the current review is mainly focused on the phytochemical investigation and pharmacological applications of R. nepalensis Main body Various secondary metabolites like emodin, endocrocin, chrysophanol, neopodin, physcion, torachrysone, aloesin, catechin, quercetin, resveratrol, and their derivatives were isolated from root and aerial parts of the plant. Both isolated compounds and extracts from R. nepalensis are reported to have pharmacological activities such as anti-inflammatory, antioxidant, antimicrobial, wound healing, and anti-plasmodial activities Conclusions Different parts of R. nepalensis have ethnomedicinal importance. R. nepalensis is one of the potential sources of pharmacologically active extracts and isolated compounds. In future R. nepalensis can play a vital role for the preparation of modern drugs. Graphical abstract

The medicinal benefits of P. lanceolata L. have been acknowledged worldwide for hundreds of years. The plant is now distributed worldwide, especially in temperate zones. This review gives an overview of ethnomedicinal use, phytochemistry, pharmacological activities, and other potential application of P. lanceolate L. Several effective chemical constituents such as polyphenols, tannins, flavonoids, alkaloids, terpenoids, iridoid glycosides, fatty acids, and polysaccharides are found in P. lanceolata L., which contribute to its exerting specific therapeutic effects. Correspondingly, studies have found that P. lanceolata L. has different biological activities, including antioxidant, antibacterial, wound-healing, anti-inflammatory, cytotoxic, and antiulcerogenic activity. The plant also treats various diseases related to the skin, respiratory organs, digestive organs, reproduction, circulation, cancer, pain relief, and infections. The plant has many applications in cosmetics such as lotion and creams; it is also used as an excellent indicator to know the presence and absence of heavy metals and the accumulation in industrial and urban areas. The plant suppresses soil nitrogen mineralization in agriculture due to allelochemicals such as aucubin. The biological activities, medicinal properties, and industrial application of P. lanceolata mainly depend on the activities of the responsible, active chemical constituents. However, this field still needs more study to determine the exact mechanisms and the main bioactive compound activity accountable for these activities. Also, most of the studies have been performed in vitro, so further in vivo studies are recommended for the future.

Background Dodonaea angustifolia is a known medicinal plant across East Arica. The flower of D. angustifolia is not well investigated in terms of phytochemistry and biological activities. This study aims to investigate the presence of flavonoids and phenolic acid in the flower of D. angustifolia and its antioxidant activity. Methods Preliminary phytochemical screening was carried out using standard protocols. Antioxidant activity evaluation using DPPH assay and total phenol content (TPC) and total flavonoid content (TFC) determinations in the flower extract was compared with the values of the leaf extract. UHPLC–DAD analysis was managed to develop the profile of the flower extract. Prediction of biological activity spectra for substances (PASS) was done using an online server for antioxidant and related activities. Results Preliminary phytochemical screening, TPC, and TFC values confirmed the presence of flavonoids and phenolic acids. From HPLC analysis of flavonoids: quercetin, myricetin, rutin, and phenolic acids: chlorogenic acid, gallic acid, and syringic acid were detected and quantified. The biological activity spectrum was predicted for the detected and quantified polyphenols. Conclusions D. angustifolia flower is a rich source of flavonoids and phenolic acids, which are extractable and can be checked for further biological activity. It was possible to identify and quantify phenolic compounds through HPLC analysis in the methanol extract of D. angustifolia flower. PASS biological activity prediction results showed that there were stronger antioxidant activities for the identified flavonoids. Future work will emphasize the isolation and characterization of active principles responsible for bioactivity.

Plants are the primary sources of cellulose. This paper is aimed at isolating cellulose from Oxytenanthera abyssinica via chemical treatments. The thermal behavior, functional group, chemical composition, crystallinity, and morphology of raw (ROA), dewaxed (DOA), alkali-treated (AOA), and bleached (BOA) fibers were examined. TGA, FTIR, DSC, DTA, XRD, and SEM were used for characterization techniques. The effects of chemical treatments were examined by determining the content of cellulose, hemicellulose, lignin, and ash. The cellulose content in the ROA improved from 49.26 ± 0.13  wt% to 86.01 ± 0.02  wt% due to the removal of noncellulose components using waxing, alkali treatment, and bleaching with alkali peroxide bleaching stages followed by aqueous chlorite in buffer solution. The highest content of cellulose and holocellulose was exhibited in the BOA samples with a yield of 86.01 ± 0.02  wt% and 97.61 ± 0.17  wt%, respectively. ROA had greater hemicellulose ( 21.31 ± 0.15  wt%), lignin ( 20.63 ± 0.12  wt%), and ash content ( 3.30 ± 0.11  wt%) in comparison to AOA and BOA. The XRD data showed a change in crystallinity after each treatment. Because of the high amount of crystalline cellulose, the XRD results revealed that BOA has a higher crystallinity index (CrI) (59.89%) and peak intensity than AOA, DOA, and ROA. The strength of the FTIR peaks increased in the order of ROA, DOA, AOA, and BOA, indicating that pretreatment causes hemicellulose and lignin to be gradually removed from the Oxytenanthera abyssinica fiber. The TGA, DTG, DTA, and DSC data also confirmed that BOA has the highest thermal stability due to the high content of cellulose. The SEM analysis showed a morphological change in the surface due to chemical treatment. These results confirmed that through chemical pretreatment, a high amount of cellulose was produced from Oxytenanthera abyssinica. Even though Oxytenanthera abyssinica is commonly grown in Ethiopia, few studies have been done on it, and no works have been carried out to isolate and characterize cellulose from the plant. Thus, the findings in this work will encourage researchers to use Oxytenanthera abyssinica as a source of cellulose for various applications, including the manufacture of cellulose nanocrystals, polymer matrix biofilters, green biocomposite reinforcing agents, and hydrogel synthesis.

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As the world’s population rises, there is a greater need for additional pulpwood for paper production worldwide. Therefore, this research aimed to evaluate the pulp and papermaking characteristics of Melia azedarach. Proximate chemical analysis, fiber morphology, pulping, bleaching, and physical tests were carried out to check the suitability of raw material. The proximate chemical analysis results showed that M. azedarach has a holocellulose content of 72.95% and a lignin content of 22.14%. Fiber morphology assessment revealed that the fibers were 0.571 mm long, 13.45 μm wide, and had a 2.52 μm cell wall thickness. Kraft pulping of M. azedarach was performed at different active alkali contents (5%, 10%, 15%, 20%, and 25%) and temperatures (150 °C, 160 °C, 170 °C, 180 °C, and 190 °C), keeping the sulfidity constant at 25%. The maximum pulp yield was 41.81% at an active alkali content of 15%, a temperature of 170 °C, and a cooking time of 90 min. The effect of pulping on the fiber morphology was studied using scanning electron microscopy, which showed that the fiber’s surface before pulping was tight and arranged in an orderly way, with a relatively complex texture. After pulping, lignin, hemicellulose, and cellulose were removed, and the fiber became softer and more loosened, containing micropores. The pulp produced was bleached, and sheet preparation and testing were performed. The prepared paper sheets had a tensile index of 23.3 Nm/g, a burst index of 1.4 kPa m2/g, and a tear index of 4.0 mN m2/g. This study concluded that M. azedarach could be a raw material for the pulp and papermaking industries. The results indicated that M. azedarach is also a potential alternative resource for pulp and paper production in Ethiopia.

Biological synthesis of silver nanoparticles (AgNPs) is a green, simple, cost-effective, time-efficient, and single-step method. This study mainly focused on the synthesis of silver nanoparticles (AgNPs) using essential oil of Laggera tomentosa (LTEO) and investigates their potential applications. Ultraviolet-Visible (UV-Vis) result showed the characteristic Surface Plasmon Resonance (SPR) peak of LTEO-AgNPs at 420 nm. Fourier transform infrared (FT-IR) spectroscopy indicated the functional groups present in LTEO and LTEO-AgNPs. Scanning electron microscope (SEM) image depicted the synthesized AgNPs mainly has spherical shapes with average nanoparticles size 89.59 ± 5.14 nm. Energy dispersive X-ray (EDX) peak at 3.0 keV showed the presence of Ag element in LTEO-AgNPs. The X-ray diffraction (XRD) peaks at 38°, 44° and 67° are assigned to (111), (200), and (220), respectively which displays the crystal nature of LTEO-AgNPs. The average particle size and zeta potential of LTEO-AgNPs were determined as 94.98 nm and −49.6 mV, respectively. LTEO-AgNPs were stable for six months against aggregation at room temperature. LTEO-AgNPs solutions exhibited potential activities for the treatment of some pathogenic bacteria species, agricultural productivity growth, determination of metallic ions, and catalytic reduction. This study is the first work to report nanoparticles synthesis using L. tomentosa extracts and evaluate their potential applications.

Background. Dodonaea angustifolia is a known medicinal plant across East Arica. The flower of D. angustifolia is not well investigated in terms of phytochemistry and biological activities. This study aims to investigate the presence of flavonoids and phenolic acids in the flower of D. angustifolia and its antioxidant activity. Methods. Preliminary phytochemical screening was carried out using the standard protocols. Antioxidant activity evaluation using DPPH assay and total phenol content (TPC) and total flavonoid content (TFC) determinations in the flower extract were compared with the values of the leaf extract. UHPLC-DAD analysis was managed to develop the profile of the flower extract. Prediction of biological activity spectra for substances (PASS) was done using an online server for antioxidant and related activities. Results. Preliminary phytochemical screening and TPC and TFC values confirmed the presence of flavonoids and phenolic acids. From the HPLC analysis of flavonoids, quercetin, myricetin, rutin, and phenolic acids such as chlorogenic acid, gallic acid, and syringic acid were detected and quantified. The biological activity spectrum was predicted for the detected and quantified polyphenols. Conclusions. D. angustifolia flower is a rich source of flavonoids and phenolic acids, which are extractable and can be checked for further biological activity. It was possible to identify and quantify phenolic compounds through HPLC analysis in the methanol extract of D. angustifolia flower. The PASS biological activity prediction results showed that there were stronger antioxidant activities for the identified flavonoids. Future work will emphasize the isolation and characterization of active principles responsible for bioactivity.