Indigo is a plant dye that has been used as an important dye by various ancient civilizations throughout history. Today, due to environmental and health concerns, plant indigo is re-entering the market. Strobilanthes cusia (Nees) Kuntze is the most widely used species in China for indigo preparation. However, other species under Strobilanthes have a similar feature. In this work, 12 Strobilanthes spp. were analyzed using electrochemical fingerprinting technology. Depending on their electrochemically active molecules, they can be quickly identified by fingerprinting. In addition, the fingerprint obtained under different conditions can be used to produce scattered patter and heatmap. These patterns make plant identification more convenient. Since the electrochemically active components in plants reflect the differences at the gene level to some extent, the obtained electrochemical fingerprints are further used for the discussion of phylogenetics.

Electrochemical analysis has become a new method for plant analysis in recent years. It can not only collect signals of electrochemically active substances in plant tissues, but can also be used to identify plant species. At the same time, the signals of electrochemically active substances in plant tissues can also be used to investigate plant phylogeny. In this work, we collected electrochemical finger patterns in Malvaceae leaves based on the established methodological strategy. After the second derivative treatment, the collected electrochemical fingerprints can show more obvious differences. Three different recognition models were used to attempt electrochemical fingerprinting. The results show that linear support vector classification can be used to identify species with high accuracy by combining the electrochemical fingerprint signals collected in the phosphoric acid buffer solution and acetic acid buffer solution. In addition, the fingerprint information collected by the electrochemical sensor is further used for phylogenetic investigation. The 18 species were divided into three clusters. Species of the same genus have been clustered together. Dendrogram obtained by electrochemical fingerprinting was used to compare previously reported results deduced from morphological and complete chloroplast genomes.

An efficient protocol for the synthesis of 2,3-dihydroquinazolinone derivatives from substituted 2-aminobenzamides and carbonyl analog catalyzed by the natural-based 5,5’-indigodisulfonic acid has been developed with good to excellent yields. Compared to the reaction conditions reported before, the use of eco-friendly and recyclable catalysts and mild reaction conditions are the major advantages of the present method. Graphical Abstract

Abelmoschus manihot (L.) flowers are widely used in traditional Chinese medicine, whereas the roots are often discarded as agricultural waste. The compact cellular and tissue architecture of the roots hinders the release of intracellular metabolites, thus impeding their reutilization. Here, enzyme-assisted ultrasonic extraction was developed to obtain a polysaccharide-rich crude extract from A. manihot roots. Orthogonal optimization identified pH 4.5, a temperature of 60 °C and a cellulase dosage of 6% (w/w) as the optimal extraction conditions, giving an extraction yield of 21.59%. The phenol–sulfuric acid assay indicated a total carbohydrate content of 75.09% (glucose equivalents). Structural analysis by Fourier transform infrared (FT−IR) confirmed the presence of characteristic polysaccharide functional groups, while monosaccharide composition analysis via high-performance liquid chromatography (HPLC) revealed the major components of glucose, glucuronic acid, rhamnose, galacturonic acid, etc. Inspired by the traditional use of A. manihot extract in papermaking, its preliminary hair care-related properties were further evaluated. At a concentration of 30 mg/mL, the extract solution inhibited Malassezia furfur growth by 84%, reduced wet and dry combing work by 16.93% and 30.86%, and increased tensile strength and tensile fracture energy by 13.04% and 14.84%, respectively. Scanning electron microscope (SEM) images suggested smoother hair fiber surfaces after treatment. These results highlight the extract’s great potential for hair care cosmetic products.