Study on the causes of changes in colour during Hibiscus syriacus flowering based on transcriptome and metabolome analyses.

BACKGROUND: The flower colour of H. syriacus 'Qiansiban' transitions from fuchsia to pink-purple and finally to pale purple, thereby enhancing the ornamental value of the cultivars. However, the molecular mechanism underlying this change in flower colour in H. syriacus has not been elucidated. In this study, the transcriptomic data of H. syriacus 'Qiansiban' at five developmental stages were analysed to investigate the impact of flavonoid components on flower colour variation. Additionally, five cDNA libraries were constructed from H. syriacus 'Qiansiban' during critical blooming stages, and the transcriptomes were sequenced to investigate the molecular mechanisms underlying changes in flower colouration. RESULTS: High-performance liquid chromatography‒mass spectrometry detected five anthocyanins in H. syriacus 'Qiansiban', with malvaccin-3-O-glucoside being the predominant compound in the flowers of H. syriacus at different stages, followed by petunigenin-3-O-glucoside. The levels of these five anthocyanins exhibited gradual declines throughout the flowering process. In terms of the composition and profile of flavonoids and flavonols, a total of seven flavonoids were identified: quercetin-3-glucoside, luteolin-7-O-glucoside, Santianol-7-O-glucoside, kaempferol-O-hexosyl-C-hexarbonoside, apigenin-C-diglucoside, luteolin-3,7-diglucoside, and apigenin-7-O-rutinoside. A total of 2,702 DEGs were identified based on the selected reference genome. Based on the enrichment analysis of differentially expressed genes, we identified 9 structural genes (PAL, CHS, FLS, DRF, ANS, CHI, F3H, F3'5'H, and UFGT) and 7 transcription factors (3 MYB, 4 bHLH) associated with flavonoid biosynthesis. The qRT‒PCR results were in good agreement with the high-throughput sequencing data. CONCLUSION: This study will establish a fundamental basis for elucidating the mechanisms underlying alterations in the flower pigmentation of H. syriacus.

Hibiscus manihot L. flower extract induces anticancer activity through modulation of apoptosis and autophagy in A549 cells.

Lung cancer is a major public health issue and heavy burden in China and worldwide due to its high incidence and mortality without effective treatment. It's imperative to develop new treatments to overcome drug resistance. Natural products from food source, given their wide-ranging and long-term benefits, have been increasingly used in tumor prevention and treatment. This study revealed that Hibiscus manihot L. flower extract (HML) suppressed the proliferation and migration of A549 cells in a dose and time dependent manner and disrupting cell cycle progression. HML markedly enhanced the accumulation of ROS, stimulated the dissipation of mitochondrial membrane potential (MMP) and that facilitated mitophagy through the loss of mitochondrial function. In addition, HML induced apoptosis by activation of the PTEN-P53 pathway and inhibition of ATG5/7-dependent autophagy induced by PINK1-mediated mitophagy in A549 cells. Moreover, HML exert anticancer effects together with 5-FU through synergistic effect. Taken together, HML may serve as a potential tumor prevention and adjuvant treatment for its functional attributes.

The utility of Hibiscus sabdariffa L. to prepare metal oxides NPs for clinical application on osteoporosis supported by theoretical study.

Green synthesis of metal oxides as a treatment for bone diseases is still exploring. Herein, MgO and Fe2O3 NPs were prepared from the extract of Hibiscus sabdariffa L. to study their effect on vit D3, Ca+2, and alkaline phosphatase enzyme ALP associated with osteoporosis. Computational chemistry was utilized to gain insight into the possible interactions. These oxides were characterized by X-ray diffraction, SEM, FTIR, and AFM. Results revealed that green synthesis of MgO and Fe2O3 NPs was successful with abundant. MgO NPs were in vitro applied on osteoporosis patients (n = 35) and showed a significant elevation of vit D3 and Ca+2 (0.0001 > p < 0.001) levels, compared to healthy volunteers (n = 25). Thus, Hibiscus sabdariffa L. is a good candidate to prepare MgO NPs, with a promising enhancing effect on vit D3 and Ca+2 in osteoporosis. In addition, interactions of Fe2O3 and MgO NPs with ALP were determined by molecular docking study.

Microwave-assisted synthesis, characterization and in vitro biomedical applications of Hibiscus rosa-sinensis Linn.-mediated carbon quantum dots.

In recent years, carbon quantum dots (CQDs) have garnered considerable attention as a promising material for biomedical applications because of their unique optical and biological properties. In this study, CQDs were derived from the leaves of Hibiscus rosa-sinensis Linn. via microwave-assisted technique and characterized using different techniques such as ultraviolet-visible, Fourier transform infrared, fluorescence spectrometry, X-ray diffraction, dynamic light scattering, transmission electron microscopy and energy-dispersive X-ray spectroscopy. Subsequently, their potential for biomedical applications was investigated through in vitro assays assessing scratch healing, anti-inflammatory, antibacterial, and cytotoxicity properties. It was found that the CQDs were fluorescent, polycrystalline, quasi-spherical, ~ 12 nm in size with presence of -OH and -COOH groups on their negatively charged surfaces, and demonstrated good anti-inflammatory by inhibiting protein denaturation, cyclooxygenase-2 and regulating inflammatory cytokines. The CQDs also exhibited antimicrobial activity against Klebsiella pneumoniae and Bacillus cereus, good biocompatibility, along with excellent promotion of cell proliferation in vitro, indicating their potential as a anti-inflammatory and wound healing material. The properties were more enhanced than their precursor, H. rosa-sinensis leaf extract. Hence, the CQDs synthesized from the leaves of H. rosa-sinensis can serve as a potential biomedical agent.

Isolation and characterisation of lignin using natural deep eutectic solvents pretreated kenaf fibre biomass.

Extraction of lignin via green methods is a crucial step in promoting the bioconversion of lignocellulosic biomasses. In the present study, utilisation of natural deep eutectic solvent for the pretreatment of kenaf fibres biomass is performed. Furthermore, extracted lignin from natural deep eutectic solvent pretreated kenaf biomass was carried out and its comparative study with commercial lignin was studied. The extracted lignin was characterized and investigated through Infrared Fourier transform spectroscopy, X-ray Diffraction, thermogravimetric analysis, UV-Vis spectroscopy, and scanning electron microscopy. FTIR Spectra shows that all samples have almost same set of absorption bands with slight difference in frequencies. CHNS analysis of natural deep eutectic solvent pretreated kenaf fibre showed a slight increase in carbon % from 42.36 to 43.17% and an increase in nitrogen % from - 0.0939 to - 0.1377%. Morphological analysis of commercial lignin shows irregular/uneven surfaces whereas natural deep eutectic solvent extracted lignin shows smooth and wavy surface. EDX analysis indicated noticeable peaks for oxygen and carbon elements which are present in lignocellulosic biomass. Thermal properties showed that lignin is constant at higher temperatures due to more branching and production of extremely condensed aromatic structures. In UV-VIS spectroscopy, commercial lignin shows slightly broad peak between 300 and 400 nm due to presence of carbonyl bond whereas, natural deep eutectic solvent extracted lignin does not show up any peak in this range. XRD results showed that the crystallinity index percentage for kenaf and natural deep eutectic solvent treated kenaf was 70.33 and 69.5% respectively. Therefore, these innovative solvents will undoubtedly have significant impact on the development of clean, green, and sustainable products for biocatalysts, extraction, electrochemistry, adsorption applications.

Exogenous methyl jasmonate enhanced kenaf (Hibiscus cannabinus) tolerance against lead (Pb) toxicity by improving antioxidant capacity and osmoregulators.

In this study, the effects of exogenous methyl jasmonate (MeJA) on metal uptake and its ability to attenuate metal toxicity in kenaf plants under Pb stress were investigated. The experiment was conducted with five different MeJA concentrations (0, 40, 80, 160, and 320 µM) as a foilar application to kenaf plants exposed to 200 µM Pb stress. The results revealed that pretreatmen of MeJA significantly increased plant dry weight, plant height, and root architecture at all concentrations tested, with the most significant increase at 320 µM. Foliar application of MeJA at 160 µM and 320 µM increased the Pb concentrations in leaves and stems as well as the translocation factor (TF) from root to leaf. However, the bioaccumulation factor in the shoot initially decreased and then increased with increasing MeJA concentration. By increasing enzymatic (SOD, POD, and CAT) and non-enzymatic (AsA and non-protein thiols) antioxidants, MeJA pretreatment decreased lipid peroxidation, O2- and H2O2 accumulation and recovered photosynthetic pigment content under Pb stress. Increased osmolytes (proline, sugar, and starch) and protein content after MeJA pretreatment under Pb stress restore cellular homeostasis and improved kenaf tolerance. Our results suggest that MeJA pretreatment modifies the antioxidant machinery of kenaf and inhibits stress-related processes that cause lipid peroxidation, hence enhancing plant tolerance to Pb stress.

Kenaf-based activated carbon: A sustainable solution for high-performance aqueous symmetric supercapacitors.

This study presents an innovative method for synthesizing activated carbon with an exceptionally high surface area (3359 m2 g-1) using kenaf fiber-based biochar through chemical activation. The achieved specific surface area surpasses activated carbon derived from other reported fiber-based precursors. The resulting activated carbon was investigated as electrodes for supercapacitors, revealing a remarkable maximum capacitance of 312 F g-1 at a current density of 0.5 A g-1. An aqueous symmetric supercapacitor employing these high-surface-area electrodes exhibited an outstanding energy density of 18.9 Wh kg-1 at a power density of 250 W kg-1. Notably, the supercapacitor retained exceptional capacitance, maintaining 93% of its initial capacitance even after 5000 charge-discharge cycles.

Determination of carbohydrate content in kenaf degumming wastewater and converting them to carbon dots.

The traditional textile degumming process produces abundant wastewater, which contains a lot of monosaccharides and oligosaccharides. It is of great economic and environmental significance to utilize these carbohydrates in high value. In this study, high performance liquid chromatography (HPLC) was used to analyze the carbohydrate components in kenaf degumming wastewater, and then the production of C-dots using the wastewater was explored. The results showed that the types and content in the degumming wastewater were monosaccharides (glucose, xylose and arabinose) and oligosaccharides (dextran, xylan and araban). The carbohydrate (mainly glucan and xylan) content in wastewater accounted for 91.16 % of the total carbohydrates weight loss in kenaf degumming process. By using hydrolysis and hydrothermal reaction on kenaf degumming wastewater, blue-green carbon dots (C-dots) with good performance were prepared and successfully applied to anti-counterfeiting printing. In particular, the as-prepared C-dots prepared from kenaf degumming wastewater with urea added (WUC-dots) showed an excitation-dependent photoluminescence (PL) spectrum and quantum yield (QY) of 2.4 % in aqueous solution. The fluorescent code exhibited a clear outline, excitation-tunable color and good stability, showing a great potential for anti-counterfeiting system.

Versatility of copper-iron bimetallic nanoparticles fabricated using Hibiscus rosa-sinensis flower phytochemicals: various enzymes inhibition, antibiofilm effect, chromium reduction and dyes removal.

Bimetallic nanoparticles (NPs) are considered superior in terms of stability and function with respect to its monometallic counterparts. Hence, in the present study Hibiscus rosa-sinensis flower extract was used to synthesis copper-iron bimetallic nanoparticles (HF-FCNPs). HF-FCNPs was characterized and its applications (biological and environmental) were determined. HF-FCNPs were spherical in shape with high percentage of copper inducted into the NPs. HF-FCNPs inhibited mammalian glucosidases [maltase (IC50: 548.71 ± 61.01 µg/mL), sucrase (IC50: 441.34 ± 36.03 µg/mL), isomaltase (IC50: 466.37 ± 27.09 µg/mL) and glucoamylase (IC50: 403.12 ± 14.03 µg/mL)], alpha-amylase (IC50: 16.27 ± 1.73 µg/mL) and acetylcholinesterase [AChE (IC50: 0.032 ± 0.004 µg/mL)] activities. HF-FCNPs showed competitive inhibition against AChE, maltase and sucrase activities; mixed inhibition against isomaltase and glucoamylase activities; whereas non-competitive inhibition against α-amylase activity. HF-FCNPs showed zone of inhibition of 16 ± 2 mm against S. mutans at 100 µg/mL concentration. HF-FCNPs inhibited biofilm formation of dental pathogen, S. mutans. SEM and confocal microscopy analysis revealed the disruption of network formation and bacterial cell death induced by HF-FCNPs treatment on tooth model of S. mutans biofilm. HF-FCNPs efficiently removed hexavalent chromium in pH-independent manner and followed first order kinetics. Through Langmuir isotherm fit the qmax (maximum adsorption capacity) was determined to be 62.5 mg/g. Further, HF-FCNPs removed both anionic and cationic dyes. Altogether, facile synthesis of HF-FCNPs was accomplished and its biological (enzyme inhibition and antibiofilm activity) and environmental (catalyst to remove pollutants) applications have been understood.

Effects of Rhizopus-arrhizus-31-Assisted Pretreatment on the Extraction and Bioactivity of Total Flavonoids from Hibiscus manihot L.

The Hibiscus manihot L. (HML) Medic, an edible hibiscus of the Malvaceae family, is abundant with flavonoids. The study investigated how Rhizopus-arrhizus-31-assisted pretreatment affects the extraction and bioactivity of flavonoids from HML. The fiber structure of the fermented flavonoid sample (RFF) appears looser, more porous, and more disordered than the unfermented flavonoid sample (RUF). RFF demonstrates milder conditions and yields higher extraction rates. According to the Box-Behnken response surface optimization experiment, the optimal conditions for RFF include a material-liquid ratio of 1:41 g/mL, a 2 h extraction time, a 57% ethanol concentration, and an extraction temperature of 800 °C, resulting in a 3.69% extraction yield, which is 39.25% higher than that of RUF. Additionally, RFF exhibits greater activity than RUF in the radical-scavenging system. The IC50 values for DPPH, OH, and ABTS radicals are 83.43 µg/mL and 82.62 µg/mL, 208.38 µg/mL and 175.99 µg/mL, and 108.59 µg/mL and 75.39 µg/mL for RUF and RFF, respectively. UPLC-QTOF-MS analysis of the active components in the HML flavonoid sample revealed significant differences in the chromatograms of RUF and RFF, indicating that biofermentation led to substantial changes in composition and content from HML.

The Potential of Roselle (Hibiscus sabdariffa) Plant in Industrial Applications: A Promising Source of Functional Compounds.

Roselle is an annual botanical plant that widely planted in different countries worldwide. Its different parts, including seeds, leaves, and calyces, can offer multi-purpose applications with economic importance. The present review discusses the detailed profile of bioactive compounds present in roselle seeds, leaves, and calyces, as well as their extraction and processing, to explore their potential application in pharmaceutical, cosmetic, nutraceutical, food and other industries. Roselle seeds with high phenolics, fiber, and protein contents, which are suitable to use in functional food product development. Besides, roselle seeds can yield 17-20% of roselle seed oil with high content of linoleic acid (35.0-45.3%) and oleic acid (27.1- 36.9%). This unique fatty acid composition of roselle seed oil makes it suitable to use as edible oil to offer the health benefits of essential fatty acid. Moreover, high contents of tocopherols, phenolics, and phytosterols were detected in roselle seed oil to provide nutritional, pharmaceutical, and therapeutic properties. On the other hand, roselle leaves with valuable contents of phenols, flavonoids, organic acid, and tocopherols can be applied in silver nanoparticles, food product development, and the pharmaceutical industry. Roselle calyces with high content of anthocyanins, protocatechuic acids, and organic acids are widely applied in food and colorant industries.

Viscoelastic behavior, gelation properties and structural characterization of Deccan hemp seed (Hibiscus cannabinus) protein: Influence of protein and ionic concentrations, pH, and temperature.

This study investigates the viscoelastic behavior, gelling properties, and structural characteristics of Deccan hemp seed protein (DHSP) to overcome limitations in its application in food formulations. Small amplitude oscillatory shear measurements were employed to investigate the impact of protein concentration, pH, ionic concentration, and temperature on DHSP's rheological features. The study revealed that the 20 % protein dispersion had the highest storage modulus (G') and yield stress at 63.96 ± 0.23 Pa and 0.61 Pa, respectively. DHSP dispersion exhibited pseudo-plastic behavior across various conditions. The gelling performance was higher at pH 4 and 8 and at ionic concentration in the range of 0.1 M - 0.5 M. Gelation time and temperature were observed from the temperature ramp test. Structural characterizations, including fluorescence spectroscopy, circular dichroism spectra, FTIR spectra, SEM, AFM images, zeta potential analysis, and DSC, provided insights into DHSP's tertiary and secondary conformation, surface characteristics, and thermal properties. Notably, the study highlighted DHSP's exceptional rheological properties, making it a promising gelling material for the food and nutraceutical industries. The findings also offer new insights into DHSP's structural characteristics, suggesting potential applications in food packaging and product development within the food industry.

Formulization and characterization of guar gum and almond gum based composite coating and their application for shelf-life extension of okra (Hibiscus esculentus).

The current novel study aims was to development and characterization of gum based (guar gum: almond gum) composite formulations with or without addition of oregano essential oils to extend the shelf life of okra at ambient condition. In this study, the optimized composite of guar gum: almond gum (75:25 V/V) prepared with addition of different concentrations (0.05, 0.1 and 0.15 % (V/V) of oregano essential oils to study their physicochemical, rheological, antimicrobial and particle size & zeta potential distribution. In addition, the effects of prepared edible coatings on shelf-life of okra vegetables were also investigated by assessing their postharvest quality attributes at ambient (23 °C) storage up to 7 days storage. The results revealed, increasing concentration of essential oils in composite coating significantly increased in pH, TSS, particle size, antimicrobial (Apergillus. niger, Escherichia coli, Staphylococcus aureus) activity respectively. Furthermore, the increasing EOs improved viscosity (n) and stability of the coatings matrix. In addition, the applications of guar gum (0.25 %): almond gum (0.5 %) composite ratio (75,25) with oregano essential oils exhibited excellent properties and potential to maintain the postharvest characteristics of okra throughout the storage period. The results of this study revealed that the addition of higher concentration (0.15 %) of essential oils in composite formulation of 75 % guar gum +25 % almond gum (03) showed higher value of pH (5.45), antioxidant activity (20.87 %), particle size (899.1 nm), zeta potential (-8.6 mV), polydispersity index (50.6 %) and higher antimicrobial activity against E.coli (19 mm), S. aureus (29 mm) and A. niger (35 mm) as compared to other formulations. Therefore, the lower composite formulation (01) with lower concentration (0.05 %) of oregano essential oil was found most effective formulation to maintain the shelf life of okra for up to 4 days as compared to other treated and control okra samples at ambient temperature by retarded the weight loss (12.74 %), maintained higher firmness (0.998 N), lower respiration rate (484.32 ml Co2/kg/h) respectively on 7 days of storage. The microbial load in the okra samples treated with different guar gum: almond gum composite showed lower microbial load in terms of total plate count and yeast & mold counts as compared to control samples. Samples treated with O3 coating showed lowest TPC (0.1 × 108 cfu/g) and YMC (6.63 × 106 cfu/g) followed by O2 (0.48 × 108 cfu/g, 7.9 × 106 cfu/g) and O1 (0.78 × 108 cfu/g, 9.45 × 106 cfu/g) respectively on 6rd day of storage, overall results indicated that the application of composite coating with different concentrations of oregano essential oils were effective to maintained postharvest shelf life of okra up to 4 days at ambient condition.

Meta-Transcriptomic Analysis Uncovers the Presence of Four Novel Viruses and Multiple Known Virus Genera in a Single Hibiscus rosa-sinensis Plant in Colombia.

Hibiscus is not native to Colombia but well suited to its arid soil and dry climates. A single hibiscus plant from Risaralda, showing black spots on upper and lower sides of its leaves, was collected for virome analysis using meta-transcriptomic high-throughput sequencing technology. Bioinformatic analysis identified 12.5% of the total reads in the Ribo-Zero cDNA library which mapped to viral genomes. BLAST searches revealed the presence of carlavirus, potexvirus, and of known members of the genera Betacarmovirus, Cilevirus, Nepovirus, and Tobamovirus in the sample; confirmed by RT-PCR with virus-specific primers followed by amplicon sequencing. Furthermore, in silico analysis suggested the possibility of a novel soymovirus, and a new hibiscus strain of citrus leprosis virus C2 in the mixed infection. Both RNA dependent RNA polymerase and coat protein gene sequences of the potex and carla viruses shared less than 72% nucleotide and 80% amino acid identities with any alphaflexi- and betaflexi-virus sequences available in GenBank, identifying three novel carlavirus and one potexvirus species in the Hibiscus rosa-sinensis plant. The detection of physalis vein necrosis nepovirus and passion fruit green spot cilevirus in hibiscus are also new reports from Colombia. Overall, the meta-transcriptome analysis identified the complex virome associated with the black spot symptoms on hibiscus leaves and demonstrated the diversity of virus genera tolerated in the mixed infection of a single H. rosa-sinensis plant.

Antioxidant and Antineoplastic Activities of Hibiscus sabdariffa Linn. Petal Extracts against Oral Squamous Cell Carcinoma Cell Line.

PURPOSE: To assess the antioxidant and antineoplastic effects of Hibiscus sabdariffa Linn. on oral squamous cell carcinoma cells. MATERIALS AND METHODS: Human squamous cell carcinoma HSCC cells were tested for cytotoxicity by a methanol extract of Hibiscus sabdariffa (MEHSP). After 24, 48, and 72 h, the MTT assay and Trypan blue exclusion test were used to determine cell survival and death. 2, 2-diphenyl-1-picrylhydrazyl (DPPH), DNA Protection Assay (DPA), and ferric reducing antioxidant power assay (FRAPA) measured the antioxidant activity of MEHSP. RESULTS: The antioxidant activity (%) ranged from 47.92-82.24 in the DPPH test, 11.61-73.65 in the DPA, and 4.97-52.09 in the FRAPA. The HSCC in-vitro cytotoxicity assay showed dose- and time-dependent cell viability. MEHSP at 5 µg/ml inhibited viable cells, while increasing MEHSP doses decreased cell viability. The Trypan blue exclusion test showed that MEHSP significantly reduced cell viability at 24, 48, and 72 h. CONCLUSION: Hibiscus sabdariffa contains antioxidant and HSCC-cytotoxic properties.

Targets and Effects of Common Biocompounds of Hibiscus sabdariffa (Delphinidin-3-Sambubiosid, Quercetin, and Hibiscus Acid) in Different Pathways of Human Cells According to a Bioinformatic Assay.

The utilization of food as a therapeutic measure for various ailments has been a prevalent practice throughout history and across different cultures. This is exemplified in societies where substances like Hibiscus sabdariffa have been employed to manage health conditions like hypertension and elevated blood glucose levels. The inherent bioactive compounds found in this plant, namely, delphinidin-3-sambubioside (DS3), quercetin (QRC), and hibiscus acid (HA), have been linked to various health benefits. Despite receiving individual attention, the specific molecular targets for these compounds remain unclear. In this study, computational analysis was conducted using bioinformatics tools such as Swiss Target Prediction, ShinnyGo 0.77, KEGG, and Stringdb to identify the molecular targets, pathways, and hub genes. Supplementary results were obtained through a thorough literature search in PubMed. DS3 analysis revealed potential genetic alterations related to the metabolism of nitrogen and glucose, inflammation, angiogenesis, and cell proliferation, particularly impacting the PI3K-AKT signaling pathway. QRC analysis demonstrated interconnected targets spanning multiple pathways, with some overlap with DS3 analysis and a particular focus on pathways related to cancer. HA analysis revealed distinct targets, especially those associated with pathways related to the nervous system. These findings emphasize the necessity for focused research on the molecular effects of DS3, QRC, and HA, thereby providing valuable insights into potential therapeutic pathways.

Unique properties of titanium dioxide quantum dots assisted regulation of growth and biochemical parameters of Hibiscus sabdariffa plants.

Owing to the uniqueness of quantum dots (QDs) as a potential nanomaterial for agricultural application, hence in the present study, titanium dioxide quantum dots (TiO2 QDs) were successfully synthesized via sol-gel technique and the physico-chemical properties of the prepared TiO2 QDs were analyzed. Based on the results, the TiO2 QDs showed the presence of anatase phase of TiO2. TEM examination revealed spherical QDs morphology with an average size of 7.69 ± 1.22 nm. The large zeta potential value (-20.9 ± 2.3 mV) indicate greater stability of the prepared TiO2 QDs in aqueous solutions. Moreover, in this work, the application of TiO2 QDs on Hibiscus sabdariffa plants was conducted, where H. sabdariffa plants were foliar sprayed twice a week in the early morning with different concentrations of TiO2 QDs (0, 2, 5, 10, 15 and 30 ppm) to evaluate their influence on these plants in terms of morphological indexes and biochemical parameters. The results exhibited an increasing impact of the different used concentrations of TiO2 QDs on morphological indexes, such as fresh weight, dry weight, shoot length, root length, and leaf number, and physio-biochemical parameters like chlorophyll a, chlorophyll b, carotenoid contents, total pigments and total phenolic contents. Remarkably, the most prominent result was recorded at 15 ppm TiO2 QDs where plant height, total protein and enzymatic antioxidants like catalase and peroxidase were noted to increase by 47.6, 20.5, 29.5 and 38.3%, respectively compared to control. Therefore, foliar spraying with TiO2 QDs positively serves as an effective strategy for inducing optimistic effects in H. sabdariffa plants.

Pan-chloroplast genomes for accession-specific marker development in Hibiscus syriacus.

Hibiscus syriacus L. is a renowned ornamental plant. We constructed 95 chloroplast genomes of H. syriacus L. cultivars using a short-read sequencing platform (Illumina) and a long-read sequencing platform (Oxford Nanopore Technology). The following genome assembly, we delineate quadripartite structures encompassing large single-copy, small single-copy, and inverted repeat (IRa and IRb) regions, from 160,231 bp to 161,041 bp. Our comprehensive analyses confirmed the presence of 79 protein-coding genes, 30 tRNA genes, and 4 rRNA genes in the pan-chloroplast genome, consistent with prior research on the H. syriacus chloroplast genome. Subsequent pangenome analysis unveiled widespread genome sequence conservation alongside unique cultivar-specific variant patterns consisting of 193 single-nucleotide polymorphisms and 61 insertions or deletions. The region containing intra-species variant patterns, as identified in this study, has the potential to develop accession-specific molecular markers, enhancing precision in cultivar classification. These findings are anticipated to drive advancements in breeding strategies, augment biodiversity, and unlock the agricultural potential inherent in H. syriacus.

Discovery of Cadinane-Type Sesquiterpenoids from the Infected Stems of Hibiscus tiliaceus as Potential Agrochemical Fungicides.

Ten new cadinane-type sesquiterpenoids, named hibisceusins I-R (1-10), along with 14 known sesquiterpenoids (11-24), were acquired from the tainted stems of Hibiscus tiliaceus. Their structures were identified via spectroscopic analysis, one-dimensional (1D) and two-dimensional (2D) NMR, and computer-assisted structure elucidation techniques, including infrared (IR) and mass spectrometry (MS) data. Additionally, subsequent DP4/DP4+ probability methods were used to resolve 3's relative configurations by comparing their experimental values to the predicted NMR data. The absolute configurations of compounds 1-4 were measured through electronic circular dichroism (ECD) spectra. The ability of all isolates to inhibit the growth of five phytopathogenic fungi (Rhizopus stolonifer, Verticillium dahliae Kleb., Thanatephorus cucumeris, Fusarium oxysporum Schltdl., and F. oxysporum HK-27) was evaluated. Aldehydated sesquiterpenoids (1, 6-9, 11, 12, and 22) and a known sesquiterpenoid quinine (18) exhibited significant inhibitory activities against V. dahliae, T. cucumeris, F. oxysporum, and F. oxysporum HK-27 with minimum inhibitory concentration (MIC) values of 2.5-50 µg/mL, but all isolates remained inactive against R. stolonifer. Moreover, the effects of the isolates on the mycelial morphology were watched through scanning electron microscopy. This study revealed that aldehydated cadinane-type sesquiterpenoids could be used as novel antifungal molecules to develop agrochemical fungicides in plant protection.

Determination of anthocyanins, organic acids, and phenolic acids in hibiscus market products using LC/UV/MS.

Hibiscus sabdariffa has gained increasing attention from consumers as a natural, healthy food ingredient, leading to a myriad of available products, yet there is a lack of understanding of the quality and chemical diversity among commercially available hibiscus products. Here, we conducted a survey on the chemistry of 29 hibiscus products (calyces, beverages, and extracts). UHPLC-DAD and UHPLC-QQQ/MS methods with high sensitivity and selectivity were developed to evaluate the chemical profiles pertaining to the sensory attributes (color and taste). Two major anthocyanins (delphinidin-3-sambubioside and cyanindin-3-sambubioside), eight organic acids, and 23 phenolic acids were identified and quantified in hibiscus market products. The results showed that hibiscus samples contained < 0.001-2.372% of total anthocyanins, 0.073-78.002% of total organic acids, and 0.001-1.041% of total phenolic acids, and demonstrated significant variations in market products. This is the first time that an in-depth organic acid profiling was conducted on hibiscus products using UHPLC-QQQ/MS. This method can also be extended to chemical profiling, sensory analysis, quality control, authentication, and standardization of other natural products.