Search Results (152)

Isoquercitrin, a monoglucoside form of quercetin, exhibits superior antioxidant, anti-inflammatory, and cardiovascular protective effects in comparison to its precursor, rutin. However, its natural abundance is limited. This study aimed to increase the functional value of Diospyros lotus leaf extract through enzymatic conversion of rutin to isoquercitrin using α-l-rhamnosidase and to evaluate the changes in biological activities after conversion. A sugar-free D. lotus leaf extract was prepared and subjected to enzymatic hydrolysis with α-l-rhamnosidase under optimized conditions (pH 5.5, 55 °C, and 0.6 U/mL). Isoquercitrin production was monitored via high-performance liquid chromatography. Antioxidant and anti-inflammatory activities were assessed using the 2,2-diphenyl-1-picrylhydrazyl radical scavenging and lipoxygenase (LOX) inhibition assays, respectively. The enzymatic reaction resulted in complete conversion of 30 mM rutin into isoquercitrin within 180 min, increasing isoquercitrin content from 9.8 to 39.8 mM. The enzyme-converted extract exhibited significantly enhanced antioxidant activity, with a 48% improvement in IC₅₀ value compared with the untreated extract. Similarly, LOX inhibition increased from 39.2% to 48.3% after enzymatic conversion. Both extracts showed higher inhibition than isoquercitrin alone, indicating synergistic effects of other phytochemicals present in the extract. This study is the first to demonstrate that α-l-rhamnosidase-mediated conversion of rutin to isoquercitrin in D. lotus leaf extract significantly improves its antioxidant and anti-inflammatory activities. The enzymatically enhanced extract shows potential as a functional food or therapeutic ingredient. Full article

This article addresses the impact of deficit irrigation on the agronomic and physiological performance of “Rojo Brillante” persimmon trees in a Mediterranean climate. It compares the effect of a sustained deficit irrigation (SDI; imposing water deficit uniformly throughout the entire crop cycle) strategy and two regulated deficit irrigation (RDI; enforcing a water deficit during the phenological phases that are less sensitive to water stress) strategies. Field trials were conducted from 2022 to 2024 at the Cajamar Experimental Center in Paiporta, Valencia, Spain. The trees respond to mild water stress reducing transpiration through stomatal closure. RDI resulted in modest irrigation water savings (11–16%), minimizing fruit drop, leading to an increased number of fruits per tree and a higher marketable yield, although this came at the cost of a reduced unit fruit weight. SDI achieved a 30% reduction in irrigation water usage without impacting on the marketable yield, but it also caused a decrease in unit fruit weight. RDI increased water productivity (yield obtained per amount of water applied) primarily through higher yields, while SDI improved productivity mainly by lowering the amount of irrigation water applied. Both irrigation strategies are recommended for cultivating “Rojo Brillante” persimmons. RDI is especially advisable in years with lower fruit loads as more intensive thinning may be necessary in years with higher fruit loads. Conversely, SDI is recommended in situations where water availability is limited. Full article

Persimmon (Diospyros kaki Thunb.) fruit can accumulate proanthocyanidins (tannins) during development, which causes astringency and affects consumption. The hormone abscisic acid (ABA) has been reported to play a key role in fruit ripening and softening. However, the effect of ABA on postharvest persimmon fruit deastringency remains unclear. In this study, we found that 300 mg/L ABA treatment could decrease the content of soluble tannins, thus leading removal of persimmon fruit astringency. The contents of acetaldehyde and ethanol did not increase during the storage time, indicating that ABA treatment-promoted persimmon fruit deastringency was not due to the acetaldehyde interaction with soluble tannins. Furthermore, the transcriptome analysis showed that 6713 differentially expressed genes (DEGs) were identified, and the WGCNA (weighted gene co-expression network analysis) showed that one module, which comprises 575 DEGs, significantly correlated with the contents of soluble and resoluble tannins. The analysis based on the carbohydrate metabolism pathway indicated that 37 differentially expressed structural genes involved in acetaldehyde metabolism were upregulated by ABA. Real-time quantitative PCR showed that the previously reported key genes, including structural genes and transcription factors, were all upregulated by ABA treatment. The obtained results indicate that ABA treatment, promoting persimmon fruit astringency removal, may occur through gel polymerization of cell wall materials with soluble tannins. Full article

The seasonality of Diospyros kaki limits its consumption, making it increasingly necessary to develop products that allow it to be available all year round. Therefore, the aim of this study was to optimize the osmotic dehydration process and to evaluate the changes in the physico-chemical, bioactive and volatile composition of persimmon subjected to drying. A central composite rotatable design was used with the independent variables as sucrose concentration (%) and immersion time (min). The desirability function for sucrose solution concentration and immersion time was 29.5% for 60 min for hot air oven drying and 38% for 29 min for freeze drying. The dehydrated fruit treated with osmotic pretreatment showed better responses in the quantification of bioactive compounds and retention of volatile compounds. Compounds such as nonanal and 6-methyl-5-hepten-2-one were identified in all the dehydrated products and the OD had a positive influence on their retention, especially for the lyophilized samples. Thus, it is clear that osmotic pretreatment is an ally in protecting the physico-chemical and chemical characteristics of the fruit when it undergoes a drying process, especially with regard to bioactive and volatile compounds. Full article

Diospyros kaki L. is acknowledged for its extraordinary phytotherapeutic properties due to the presence of polyphenols, carotenoids, and flavonoids such as β-cryptoxanthin and rutin. These compounds are largely distributed in the skin and flesh of the fruit. In this study, the different parts of persimmons were analyzed (whole fruit, peels, and flesh), aiming at determining total carotenoid and flavonoid content through selective extraction and HPLC-DAD analysis. Obtained by a one-pot double phase extraction, organic and aqueous extracts were submitted to colorimetric analyses and tested for their antifungal activity. Results indicated that carotenoid and flavonoid content varied with sample maturity, and colorimetry proved to be an effective predictor of pigments’ composition. The strongest antifungal and antibiofilm activity has been demonstrated for the hydroalcoholic extracts of the unripe whole fruit and flesh. Preliminary results suggest their potential application in preventing Candida infections by inhibiting their establishment. Although further studies are needed, these results open the way to the possible use of the extracts as additives in foods or in the preparation of pharmaceutical formulations for the prevention of infections caused by Candida albicans, helping to reduce the use of synthetic biocidal products. Full article

Persimmon (Diospyros kaki) plants showing yellowing, reddening, die-back, and decline symptoms were observed in Mehriz (Yazd province), Iran. Total DNAs, extracted from samples collected from symptomatic and symptomless plants, were subjected to direct and nested PCR, amplifying the 16S rRNA gene of phytoplasmas using specific primer pairs. PCR amplicons of expected lengths were obtained, mainly from nested PCR, and only from samples collected from symptomatic plants. Real and virtual RFLP, phylogenetic, and DNA identity analyses of the partial 16S rRNA gene sequences suggested the presence of diverse phytoplasmas in the analyzed samples. The identified phytoplasmas were referable to ‘Candidatus Phytoplasma omanense’ (16SrXXIX group) and ‘Ca. P. australasiae = australasiaticum’ (16SrII-D subgroup). The results of the sampling and testing highlight the urgent need for an accurate survey to verify the presence and identity of phytoplasmas in symptomatic fruit trees in Iran, in order to be able to plan appropriate management strategies. Further investigations of the possible role of ‘Ca. P. omanense’ strains as an emerging threat to fruit orchards in Iran should also be performed. Full article

Trunk sap flow is essential for assessing plant water use efficiency and adaptation, yet the mechanisms underlying drought resistance and water utilization strategies in dry and hot valleys remain poorly understood. This study investigates the sap flow dynamics of four tree species (Albizia kalkora, Diospyros dumetorum, Terminalia franchetii, and Acacia auriculiformis) in a dry and hot valley using Granier’s thermal diffusion probe method. The aims were to analyze interspecific differences and their response mechanisms to environmental factors using a fitted model of sap flow density and transpiration variables, supplemented by Pearson’s and Mantel’s tests. The results showed that (1) the trunk sap flow of each tree species is significantly higher in the wet season than in the dry season. (2) In the dry and wet seasons, the average trunk sap flow rates were in the order Albizia kalkora > Diospyros dumetorum > Terminalia franchetii > Acacia auriculiformis. (3) The correlation between environmental factors and trunk sap flow was in the order photosynthetically active radiation > atmospheric temperature > saturated water vapor pressure difference > relative humidity > wind speed. (4) Deciduous plants demonstrated stronger water-conducting capacities than evergreen plants and native plants exhibited better drought resistance than introduced plants. (5) Acacia auriculiformis and Albizia kalkora were identified as rainfall-sensitive plants, while Diospyros dumetorum and Terminalia franchetii were rainfall-insensitive. By optimizing species selection based on water use efficiency, rainfall sensitivity, and environmental conditions such as light and temperature, this research contributes to enhancing the stability and resilience of ecosystem restoration in arid regions. Full article

Astringency in persimmon fruit is often eliminated by treatment with gaseous carbon dioxide, dry ice, or alcohol. However, these methods are time-consuming and labor-intensive, and astringency may recur after heat treatment. In this study, a method for easily reducing astringency was investigated by taking advantage of the benefits of combining proteins and polysaccharides. In the first experiment, the protein materials with strong astringency-reducing effects were screened from among 15 protein-rich foods using astringent persimmon juice (APJ), and collagen peptides were found to be highly effective. However, syneresis was observed when 1% collagen peptide powder was added to the astringent persimmon paste (AP). Therefore, in the second experiment, 0.5% collagen peptides (protein) were applied to reduce heating-induced astringency and reversion and 0.5% polysaccharides (guar, and xanthan gums) to maintain color and suppress syneresis. The results demonstrate that the combination of collagen peptide and polysaccharides is optimal for removing astringency in persimmon, inhibiting its recurrence by heating, and maintaining product quality. The results of this study may reduce the labor required for the astringency removal process, broaden the uses of AP, and facilitate the effective utilization of discarded astringent persimmons that do not meet the standards. Full article

This study investigates the Fukugi (Garcinia subelliptica) windbreak landscapes on Iriomote Island through case studies in two of its oldest villages, Sonai and Hoshitate. These windbreak forests, integral to the cultural landscape of Okinawa, offer both ecological and socio-economic benefits. Using field measurements and surveys, the research analyzes the distribution, growth patterns, and historical significance of Fukugi groves within the village setting and compares naturally regenerated forests with those planted by humans. The findings underscore the importance of Fukugi trees in promoting sustainable rural landscapes, where they dominate the local ecosystem of rural settlements. Fukugi windbreak landscapes in Okinawa are characterized by trees encircling homes on all four sides, distinguishing them from homestead windbreaks found in other regions of Japan. Surveys from the two villages suggest that the original homestead windbreak forests in the Yaeyama region contain a diverse mix of tree species, with Fukugi and Calophyllum inophyllum being predominant, along with other useful species like Diospyros ferrea and Podocarpus macrophyllus. These species were selected not only for their windbreak capabilities but also for timber and home furniture production. The study’s findings on naturally regenerated Fukugi groups support the hypothesis that the cultivation of Fukugi as a windbreak species originated in the Yaeyama region and likely spread to other parts of Okinawa, influencing both the ecological and cultural evolution of the region’s landscapes. Full article

Cultivated persimmon (Diosspyros kaki Thunb.) is a hexaploid (mostly) or a nonaploid with high heterozygosity, hindering molecular genetic studies on proanthocyanidin (PA) metabolism, which is a major trait for persimmon astringency. Recently, one of its wild diploid relative species, oily persimmon (Diospyros oleifera), has been assembled with a chromosome-level reference. Thus, oily persimmon is now regarded as a model plant for discovering new genes associated with PA metabolism, which is highly accumulated in the fruits of this genus. In our study, we identified genome-wide microRNAs (miRNAs) and their precursor sequence based on the chromosome-scale genome of oily persimmon and the miRNA database of “Eshi 1” according to the sequence alignment and secondary structure accession. The targets were predicted on the psRNATarget software based on the genome CDS database. The size, conservation, diversity, stem-loop hairpin structures, and genome location of miRNA or the precursor sequence were analyzed by bioinformatics tools. The promoter elements of the miRNA genes were predicted on the promoter-2.0 software, which indicated that the abundant cis-acting elements were light responsiveness, promoter, and enhancer regions. The qRT-PCR assay was performed to elucidate the potential expression patterns of precursor miRNA and their targets during fruit development, and one target gene, DkMYB22, of miR2911 was verified to promote the conversion of soluble tannins into insoluble tannins involved in the deastringency in persimmons. Together, this study provides a robust foundation for further functional verification of these miRNAs associated with the natural deastringency process in persimmon, thereby facilitating advancements in persimmon fruit breeding. Full article

A single-center, randomized, double-blind, and placebo-controlled clinical trial assessed the efficacy in improving body composition and in weight management of a dietary supplement consisting of 400 mg of a standardized extract of the persimmon fruit (Diospyros kaki L.f.) in adult subjects with a BMI between 25 and 34.99 kg/m² administered for 120 consecutive days. In total, 36 participants were assigned to the placebo group and 35 to the experimental group (registered at ClinicalTrials.gov (NCT05750342)). Primary analysis focused on overweight subjects (placebo, n = 26; experimental, n = 23). In this group, fat mass expressed in kg and percentage evaluated by both dual-energy X-ray absorptiometry (DEXA) and bioelectrical impedance analysis (BIA) decreased significantly (between-group differences p < 0.001) in those receiving the persimmon extract as compared with the placebo. No significant reduction in lean mass was observed, suggesting that the muscle mass was maintained during fat loss. The use of the investigational product improved classic anthropometric parameters to a statistically significantly greater extent than the placebo, including body weight, BMI, and waist and abdominal circumference (p < 0.001), in the overweight group. In the overall population, similar improvements were observed, with significant between-group differences (p < 0.001) in fat mass reduction and improvements in body composition. Changes in the biochemical lipidic, glycemic, and anti-inflammatory profile were not found, except for between-group significant differences (p < 0.001) in decreases in tumor necrosis factor-alpha (TNFα) and increases in total antioxidant capacity (TAC) in favor of the experimental condition. There was a significant increase in fecal fat excretion in the experimental group at the end of the study in subjects with low fecal fat (9%) at baseline. Consumption of the investigational product vs. placebo improved the quality of life, with significantly greater scores in the total score and the mental health component of the SF-12 questionnaire. The persimmon extract was safe and well tolerated. Full article

Organic acids are naturally present in plants and exert a positive influence on plant development, which justifies surveying their potential effect on adventitious root (AR) formation. In this study, 0.0298 mol/L (4000 mg/L) of malic acid and 0.0267 mol/L (4000 mg/L) of tartaric acid were used to explore the effects of low-molecular-weight organic acid on the rooting of persimmon rootstock Diospyros lotus L. during cutting propagation. After organic acid treatment, the rooting percentage and the survival rate significantly increased, accompanied by a greater development of lateral roots. Anatomical analysis revealed that Diospyros lotus L. exhibits characteristics that induce root primordia, and organic acid treatment can enhance the differentiation of root primordia. Furthermore, treatment with organic acid led to a substantial decrease in soluble sugar and starch contents, along with a slight increase in soluble protein content during early cutting stages. Additionally, the indole-3-acetic acid (IAA) content peaked in the early stages of AR formation and was significantly higher than that of the control, while abscisic acid (ABA) levels exhibited the opposite trend. Comparatively, gibberellic acid (GA₃) remained at extremely low levels throughout the rooting process in the organic acid groups compared to the control. In conclusion, the current study uncovers the anatomical structure over time during AR formation, revealing the dynamic changes in the related main nutrients and hormones and providing new ideas and a new practical approach for improving root regeneration in persimmon rootstock cuttings. Full article

This study developed a new energy bar using the astringent ‘Rojo Brillante’ variety of persimmons to address postharvest losses. The bar was formulated with dehydrated persimmons, walnuts, hazelnuts, and chia seeds to enhance their nutritional profile. The proximate composition was evaluated and the mechanical and optical properties, soluble tannins, carotenoids, and antioxidant activities were monitored during storage. In addition, in vitro gastrointestinal digestion was performed to determine the recovery index of the bioactive compounds. The results showed that the formulated energy bar contained higher levels of healthy fats, proteins, and fibers than other fruit energy bars. The mechanical properties of dehydrated persimmon effectively supported the consistency of the bar, eliminating the need for hydrocolloids or syrups. During storage, soluble tannin content decreased, mitigating astringency issues commonly found in persimmon products, whereas carotenoid levels and antioxidant activity remained stable. In vitro digestion analysis revealed a higher recovery index for soluble tannins (180.08%) than carotenoids (9.87%). This persimmon-based energy bar offers a sustainable and nutritious option for the snack industry, catering to consumer preferences for natural products while contributing to the reduction of agricultural waste. Full article

Background/Objectives: Diospyros kaki, the most widely cultivated species of persimmon, has been long used in traditional medicine since its leaves’ extracts contain high amounts of flavonoids and terpenoids, endowed with several beneficial effects. However, its anticancer activity towards colorectal cancer (CRC) has not been investigated in depth. Methods: The effect of a methanolic extract of D. kaki leaves, rich in kaempferol and quercetin derivatives, have been evaluated on an E705 CRC cell line, representative of most CRC patients, and on SW480 cells, carrying a KRAS-activating mutation. Results: This extract is effective in reducing tumor cells’ viability without affecting the healthy mucosa cell line CCD 841. In fact, Western blot experiments showed its ability to induce apoptosis in cancer cells by increasing oxidative stress and disrupting mitochondrial functionality, as shown by reactive oxygen species measurement and Seahorse analysis. Conclusions: With the aim of increasing healthspan, as well as the substantial societal and macroeconomic costs associated with cancer, our results could pave the way to a role for D. kaki extract in both CRC treatment and prevention. Full article

Antioxidants are essential for mitigating oxidative stress and maintaining vascular health. Endothelial colony-forming cells (ECFCs) are pivotal in endothelial regeneration and angiogenesis and serve as a model to study the diversity of endothelial cells across various organs. This study evaluated the effects of peel, pulp, and seed extracts from Diospyros digyna Jacq. fruit (black persimmon) on human cord blood-derived ECFCs (CB-ECFCs) to determine how the distinct antioxidant profiles of the fruit’s different parts influence cellular functions. The extracts did not affect endothelial marker expression, cell proliferation, or nitric oxide production, indicating no cytotoxic or inflammatory effects. However, functional assays revealed that the seed extract significantly enhanced tube formation, increasing closed tubular networks by 1.5-fold. All extracts promoted cell migration, with the seed extract demonstrating the most substantial effect, surpassing even vascular endothelial growth factor (VEGF). Additionally, the seed extract exhibited the strongest reduction in cellular senescence, both before and after oxidative stress induction with H₂O₂. These findings underscore the potential of black persimmon extracts, especially from the seed, to enhance the regenerative capabilities of CB-ECFCs and reduce cellular senescence without affecting the normal endothelial phenotype. This positions them as promising candidates for developing endothelial cell therapies and advancing vascular regeneration. Full article