Crop calendar optimization for climate change adaptation in yam farming in South-Kivu, eastern D.R. Congo.

The traditional crop calendar for yam (Dioscorea spp.) in South-Kivu, eastern Democratic Republic of Congo (DRC), is becoming increasingly inadequate given the significant climatic variability observed over the last three decades. This study aimed at: (i) assessing trends in weather data across time and space to ascertain climate change, and (ii) optimizing the yam crop calendar for various South-Kivu agro-ecological zones (AEZs) to adapt to the changing climate. The 1990-2022 weather data series were downloaded from the NASA-MERRA platform, bias correction was carried out using local weather stations' records, and analyses were performed using RClimDex 1.9. Local knowledge and CROPWAT 8.0 were used to define planting dates for yam in different AEZs. Results showed the existence of four AEZs in the South-Kivu province, with contrasting altitudes, temperatures, and rainfall patterns. Climate change is real in all these South-Kivu's AEZs, resulting either in rainfall deficits in some areas, or extreme rainfall events in others, with significant temperature increases across all AEZs. Suitable yam planting dates varied with AEZs, September 15th and 20th were recommended for the AEZ 2 while October 15th was optimal for AEZ 1, AEZ 3, and AEZ 4. However, none of the planting date scenarios could meet the yam water requirements in AEZ1, AEZ3, and AEZ4, since the effective rainfall (Pmm) was always inferior to the plant water demand (ETc), meaning that soil water conservation practices are needed for optimum plant growth and yield in these AEZs. This study does not recommend planting yam during the short rainy season owing to prolonged droughts coinciding with critical growth phases of yam, unless supplemental irrigation is envisaged. This study provided insights on the nature of climate change across the past three decades and suggested a yam crop calendar that suits the changing climate of eastern DRC.

Sulfated Chinese yam polysaccharide exert anti-inflammatory potential via MAPK/NF-κB signaling pathways in a co-culture system and LPS-induced acute inflammatory mice model.

Our previous study has demonstrated that sulfated Chinese yam polysaccharide (SCYP) can improve immunomodulatory activity in Raw 264.7 cells. However, its anti-inflammatory is little known. In this study, the anti-inflammatory effects of SCYP were systematically investigated via the Lipopolysaccharides (LPS)-induced Raw264.7 cell model, Caco-2/Raw264.7 co-culture system, and acute inflammation mice model. The results suggested SCYP promoted the cell proliferation and have no toxicity in Raw264.7 and Caco-2 cells at the concentration of 200 µg/mL. Moreover, when treated with SCYP, the production of pro-inflammatory cytokines (interleukin [IL]-1ß, IL-6, and tumor necrosis factor-α) reduced significantly in Raw264.7 via the MAPK/NF-κB pathway. In the Caco-2/Raw264.7 co-cultured system, SCYP could regulate inflammation reaction by improving intestinal barrier, which might prevent systemic inflammation. Further, systemic inflammation was alleviated by SCYP in LPS-induced acute inflammation mice through MAPK/NF-κB pathway. PRACTICAL APPLICATION: These results supported that SCYP may be used as an anti-inflammation agent in the functional food field.

Characterization of active transposable elements and their new insertions in tuber propagated greater yam (Dioscorea alata).

BACKGROUND: Greater yam is a key staple crop grown in tropical and subtropical regions, while its asexual propagation mode had led to non-flowering mutations. How transposable elements contribute to its genetic variations is rarely analyzed. We used transcriptome and whole genome sequencing data to identify active transposable elements (TEs) and genetic variation caused by these active TEs. Our aim was to shed light on which TEs would lead to its intraspecies variation. RESULTS: Annotation of de novo assembly transcripts indicated that 0.8 - 0.9% of transcripts were TE related, with LTR retrotransposons (LTR-RTs) accounted for 65% TE transcripts. A large portion of these transcripts were non-autonomous TEs, which had incomplete functional domains. The majority of mapped transcripts were distributed in genic deficient regions, with 9% of TEs overlapping with genic regions. Moreover, over 90% TE transcripts exhibited low expression levels and insufficient reads coverage to support full-length structure assembly. Subfamily analysis of Copia and Gypsy, the two LTR-RTs revealed that a small number of subfamilies contained a significantly larger number of members, which play a key role in generating TE transcript. Based on resequencing data, 15,002 L-RT insertion loci were detected for active LTR-RT members. The insertion loci of LTR-RTs were highly divergent among greater yam accessions. CONCLUSIONS: This study showed the ongoing transcription and transpositions of TEs in greater yam, despite low transcription levels and incomplete proteins insufficient for autonomous transposition. While our research did not directly link these TEs to specific yam traits such as tuber yield and propagation mode, it lays a crucial foundation for further research on how these TE insertion polymorphisms (TIPs) might be related to variations in greater yam traits and its tuber propagation mode. Future research may explore the potential roles of TEs in trait variations, such as tuber yield and stress resistance, in greater yam.

Aqueous extracts from Dioscorea sansibarensis Pax show cytotoxic and radiosensitizing potential in 3D growing HPV-negative and HPV-positive human head and neck squamous cell carcinoma models.

Numerous natural substances have anti-cancer properties. Especially indigenous people use aqueous plant extracts for tea or ointments including Dioscorea sansibarensis Pax to treat various diseases. The aim of this study was to evaluate the cytotoxic and radiosensitizing potential of aqueous extracts from Dioscorea sansibarensis Pax collected from Kenya in a panel of HPV-negative and -positive head and neck squamous cell carcinoma (HNSCC) cells grown in three-dimensional laminin-rich extracellular matrix (3D lrECM). The results show cytotoxicity, radiosensitization and increased levels of residual double strand breaks (DBS) by Dioscorea sansibarensis Pax extracts in HPV-negative and -positive HNSCC models in a concentration- and cell model-dependent manner. Application of ROS scavengers indicated an association between ROS-induced DSB and radiosensitization through Dioscorea sansibarensis Pax pretreatment. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) based characterization of Dioscorea sansibarensis Pax identified the main components of the extract including camptothecin. Overall, Dioscorea sansibarensis Pax aqueous extracts alone and in combination with X-ray irradiation showed effective anticancer properties, which are worthy of further mechanistic investigation.

Investigating the Discoloration of Leaves of Dioscorea polystachya Using Developed Atomic Absorption Spectrometry Methods for Manganese and Molybdenum.

The Chinese yam (Dioscorea polystachya, DP) is promising for the food and pharmaceutical industries due to its nutritional value and pharmaceutical potential. Its proper cultivation is therefore of interest. An insufficient supply of minerals necessary for plant growth can be manifested by discoloration of the leaves. In our earlier study, magnesium deficiency was excluded as a cause. As a follow-up, this work focused on manganese and molybdenum. To quantify both minerals in leaf extracts of DP, analytical methods based on atomic absorption spectrometry (AAS) using the graphite furnace sub-technique were devised. The development revealed that the quantification of manganese works best without using any of the investigated modifiers. The optimized pyrolysis and atomization temperatures were 1300 °C and 1800 °C, respectively. For the analysis of molybdenum, calcium proved to be advantageous as a modifier. The optimum temperatures were 1900 °C and 2800 °C, respectively. Both methods showed satisfactory linearity for analysis. Thus, they were applied to quantify extracts from normal and discolored leaves of DP concerning the two minerals. It was found that discolored leaves had higher manganese levels and a lower molybdenum content. With these results, a potential explanation for the discoloration could be found.

Effect of extrusion using plasma-activated water on the structural, physicochemical, antioxidant and in vitro digestive properties of yam flour.

The synergistic effects of plasma-activated water (PAW) and twin-screw extrusion (TSE) on the structural, physicochemical, antioxidant, and digestive properties of yam flour (YF) were studied. Compared to common TSE, PAW-TSE reduced the protein, starch, and polyphenol contents, swelling power, and gel property of YF, while PAW-TSE enhanced the flavonoid content, whiteness index, solubility, and antioxidant property of YF. Moreover, the results of structural characterization and differential scanning calorimetry indicated that the long-range or short-range ordering, and gelatinization enthalpy of starch in YF were reduced after PAW-TSE, while the structure ordering of proteins in YF increased. Furthermore, the in vitro digestibility results demonstrated a reduction in the rate of enzymatic hydrolysis, coupled with an increase in total contents of slowly digestible and resistant starch after PAW-TSE. It should be noted that TSE using PAW prepared by a longer plasma treatment resulted in a more significant improvement effect on YF.

Pullulanase-assisted bamboo leaf flavonoids optimize the instant properties, in vitro digestibility, and underlying mechanism in yam flour.

In this study, pullulanase-assisted bamboo leaf flavonoids (BLF) were employed to ameliorate limitations of fluidity and digestibility of cooked yam flour via physicochemical properties, digestion, structure and interaction analysis. The results showed that 1) Pullulanase-assisted BLF significantly increased the water solubility (9.02% â†’ 69.38%) and inhibited the swelling (5.54 g/g â†’ 2.29 g/g) during heating and cooling of yam flour, causing it to have liquid-like rheological properties (the tanδ tended to 1). 2) Pullulanase and BLF synergistically affected the anti-digestion of yam flour, reducing the estimated glycemic index to a lower level (58.27 â†’ 48.26, dose-dependent of BLF). 3) Pullulanase-assisted BLF mainly interacted hydrophobic with various components, especially starch, increasing the short/long-range ordered structure of starch, changing the secondary structure of proteins, and forming a tight three-dimensional network structure. This study provided a theoretical foundation for the development of functional foods using yam flour and its potential application in liquid foods.

Zearalenone removal using inactivated yeast embedded in porous modified yam starch aerogels and its application in corn silk tea.

Zearalenone contaminates food and poses a threat to human health. It is vital to develop cost-effective and environmentally-friendly adsorbents for its removal. By screening Sporobolomyces pararoseus (SZ4) and modified yam starch (adsorption capacity (qe) of 1.33 and 0.94 mg/g, respectively), this study prepared a novel composite aerogel adsorbent (P-YSA@SZ410). The compressive strength of P-YSA@SZ410 was 1.35-fold higher than unloaded yeast. It contained several functional groups and three-dimensional interconnected channels, achieving a 0° contact angle within 0.18 s, thereby demonstrating excellent water-absorbent properties. With a qe of 2.96 mg/g at 308 K, the adsorption process of P-YSA@SZ410 was spontaneous, endothermic, and matched pseudo-second-order and Langmuir models. The composite adsorbed zearalenone via electrostatic attraction and hydrogen bonding, maintaining a qe of 2.24 mg/g after five cycles. P-YSA@SZ410 was found to remove zearalenone effectively under various conditions and could be applied to corn silk tea, indicating its great potential as an adsorbent material.

Rapid discriminant analysis for the origin of specialty yam based on multispectral data fusion strategies.

In order to achieve rapid and effective identification of Hebei yam, a qualitative discrimination model was constructed based on near infrared (NIR), mid infrared (MIR), and microscopic Raman spectra in combination with individual spectra and multispectral data fusion strategies. The results showed that the gray wolf optimizer-support vector machine (GWO-SVM) model constructed by mid-level fusion using the three feature spectra performed the best in distinguishing the geographic origin of the yam, with a prediction accuracy of 100.00% in both the training set and the test set, and an F1 score of 1.00. The results indicated that due to spectral complementarity, NIR, MIR and Raman combined with feature-level fusion can be used as a powerful, non-destructive, fast and feasible tool for geographic origin classification and brand protection of Hebei yam. This work is expected to be a potential method for origin identification analysis and quality monitoring in the food and pharmaceutical industries.

Kombucha with yam: Comprehensive biochemical, microbiological, and sensory characteristics.

Consumer demand for functional foods has increased, helping to popularize and increase the consumption of Kombucha. Other substrates have been used together with tea to improve the functional and sensory properties of the beverage. Thus, this study evaluated the comprehensive biochemical, microbiological, and sensory characteristics of kombuchas fermented with green tea (Camellia sinensis) and different concentrations of yam (0, 10, and 20 % w/v). Based on pre-tests to detect the best concentration of yam in the beverage (10, 20, 30, and 40 %) and fermentation time (5, 7, and 14 days),the concentrations of 10 and 20 % of yam and five days of fermentation were selected through pH, °Brix, and sensory analysis. During the kombucha fermentation, there was a decrease in °Brix and pH. Sucrose, glucose, fructose, citric, and succinic acids were related to the beginning of fermentation, and lactic and acetic acids were more related to the end of fermentation in the treatment containing 20 % yam. The fermentation time did not change the color of the kombucha. Fatty acids, phenols, terpenoids, and alcohols were the volatile groups with the most compounds identified. Only two yeast genera were identified (Brettanomyces bruxellensis and Pichia membranifaciens), and bacteria of the genera Acetobacter, Lactobacillus, Pantoea, Pseudomonas, Azospirillum, and Enterobacter. The beverage control showed less turbidity and more clear. The fruity descriptor was more perceived in treatments with yam. However, the perception of the apple descriptor decreases as the yam concentration increases. The yam's concentration alters the kombucha's microbiota and sensory characteristics, mainly appearance and acidity. Kombucha fermentation using yam extract is viable, and the product is sensorially accepted. However, technological improvements, such as yam flour, could be made mainly for appearance and taste attributes.

Exploring the genetic diversity and population structure of aerial yams (Dioscorea bulbifera L.) DArT-seq and agronomic traits.

Dioscorea bulbifera is an edible yam specie with aerial bulbils. Assessing the genetic diversity of D. bulbifera accession for cultivation and breeding purposes is essential for it genetic improvement, especially where the crop faces minimal attention. The aims of this study was to assess the genetic diversity of Dioscorea bulbifera accessions collected from Nigeria and accessions maintained at the genebank of International Institute of Tropical Agriculture (IITA) Ibadan. Accessions were profiled using quatitative and qualitative phenotypic traits and Diversity Array Technology SNP-markers. Multivariate analysis based phenotypic traits revealed high variability among the evaluated accessions and all phenotypic traits assessed were useful in discriminating the aerial yam accessions. Clustering analysis based phenotypic traits revealed the presence of two well defined clusters. Using DArT-Seq marker, the 94 accessions were classified into three genetic group through the admixture and the phylogeny analysis. The comparision of phenotypic and genotypic clustering revealed inconsistency membership across the two clustering methods. The study established a baseline for the selection of parental lines from the genetic groups for genetic improvement of the D. bulbifera.

Phytoecdysteroids from Dioscorea dumetorum (Kunth) Pax. and their antioxidant and antidiabetic activities.

Diabetes is a significant global health challenge, affecting circa 540 million adults worldwide. Dioscorea dumetorum, a Nigerian folkloric antidiabetic plant is severely understudied in terms of its bioactive phytochemical constituents. Antidiabetic guided isolation of the tubers and peels of D. dumetorum afforded three phytoecdysteroids bearing a cis-fused A/B ring junction including two new ones: 24-hydroxymuristerone A (1) and 24-hydroxykaladasterone (2), alongside the known muristerone A (3). Additionally, 2,2',7,7'-tetramethoxy-[1,1'-biphenanthrene]-4,4',6,6'-tetraol (4), batatasin I (5), and dihydroresveratrol (6) were isolated. Structural elucidation relied on spectroscopic, spectrometric methods, and comparison with existing literature. The ethyl acetate extracts of both the tubers and peels of D. dumetorum exhibited the highest phenolic content, correlating with potent antioxidant activity. Compounds 4 (IC50 = 0.10 mg/mL) and 6 (IC50 = 0.22 mg/mL) demonstrated superior inhibitory effects against α-glucosidase compared to acarbose (IC50 = 0.63 mg/mL). In contrast, compounds 3, 4, and 5 showed reduced α-amylase inhibition, with IC50 values of 2.58, 3.78, and 1.12 mg/mL, respectively, compared to acarbose (IC50 = 0.42 mg/mL). These observed bioactivities validate the traditional use of D. dumetorum and contribute valuable phytochemical data to the scientific literature of the species.

Alleviation of Menopausal Symptoms by Yam (Dioscorea japonica Thunb.) and Gromwell (Lithospermum erythrorhizon Sieb. Et Zucc.) Extracts in Ovariectomized Mice.

SCOPE: The decline in estrogen during menopause contributes to a variety of menopausal symptoms, for which hormone replacement therapy (HRT) has been extensively applied. Regarding side effects and limited effectiveness of HRT for specific individuals, there is a growing interest in safe alternatives such as phytoestrogens which are structurally analogous to estrogens. This study aims to investigate the efficacy of yam and gromwell extracts, rich in bioactive compounds, and the synergistic effect of extracts on symptoms induced by estrogen deficiency in ovariectomized (OVX) mice. METHODS AND RESULTS: OVX mice receive dietary intervention of either yam, gromwell extract, or their mixture for 14 weeks. Sham-operated mice and E2-injected OVX mice serve as positive controls. Following 14 weeks of oral administration, blood, adipose tissue, vagina, uterus, femurs, and tibias are harvested for further investigation. Consequently, yam and gromwell extracts ameliorate menopausal conditions such as weight gain, glucose intolerance, dyslipidemia, and osteoporosis in estrogen-deficient OVX mice. In addition, the mixture of yam and gromwell extracts synergistically aids in the relief of the indications. CONCLUSION: These results indicate the potential use of yam and gromwell extracts, as well as their mixture, for the development of healthy functional foods to modulate menopausal symptoms.

Pseudomonas fortuita sp. nov., isolated from the endosphere of a wild yam.

A Gram-negative, strictly aerobic bacterial strain was isolated from asymptomatic leaf tissue of a wild yam plant. Optimal growth was observed at 28 °C and pH 7, and catalase and oxidase activities were detected. Polyphasic taxonomic and comparative genomics revealed that strain LMG 33091T represents a novel species of Pseudomonas. The nearest phylogenetic neighbours of strain LMG 33091T were Pseudomonas putida NBRC 14164T (with 99.79 % 16S rRNA sequence identity), Pseudomonas alkylphenolica KL28T (99.28 %) and Pseudomonas asplenii (99.07 %) ATCC 23835T. MALDI-TOF MS analysis yielded distinct profiles for strain LMG 33091T and the nearest phylogenetic neighbours. Average nucleotide identity analyses between the whole genome sequence of strain LMG 33091T and of the type strains of its nearest-neighbour taxa yielded values below the species delineation threshold and thus confirmed that the strain represented a novel Pseudomonas species, for which we propose the name Pseudomonas fortuita sp. nov., with strain LMG 33091T (=GMI12077T= CFBP 9143T) as the type strain.

White yam (Dioscorea rotundata) plants exhibiting virus-like symptoms are co-infected with a new potyvirus and a new crinivirus in Ethiopia.

White yam (Dioscorea rotundata) plants collected from farmers' fields and planted at the Areka Agricultural Research Center, Southern Ethiopia, displayed mosaic, mottling, and chlorosis symptoms. To determine the presence of viral pathogens, an investigation for virome characterization was conducted by Illumina high-throughput sequencing. The bioinformatics analysis allowed the assembly of five viral genomes, which according to the ICTV criteria were assigned to a novel potyvirus (3 genome sequences) and a novel crinivirus (2 genome sequences). The potyvirus showed ~ 66% nucleotide (nt) identity in the polyprotein sequence to yam mosaic virus (NC004752), clearly below the demarcation criteria of 76% identity. For the crinivirus, the RNA 1 and RNA 2 shared the highest sequence identity to lettuce chlorosis virus, and alignment of the aa sequence of the RdRp, CP and HSP70h (~ 49%, 45% and 76% identity), considered for the demarcation criteria, revealed the finding of a novel virus species. The names Ethiopian yam virus (EYV) and Yam virus 1 (YV-1) are proposed for the two tentative new virus species.

Protection effect of Dioscoreae Rhizoma against ethanol-induced gastric injury in vitro and in vivo: A phytochemical and pharmacological study.

ETHNOPHARMACOLOGICAL RELEVANCE: Dioscoreae Rhizoma, a kind of Chinese yam, is a medicinal and edible plant used in China for strengthening the spleen and stomach. However, there is a lack of modern pharmacology studies regarding its anti-gastric injury activity. AIM OF THE STUDY: This study aimed to investigate the phytochemical composition of Chinese yam aqueous extract (CYW) and evaluate its gastroprotective effects against ethanol-induced gastric injury in vitro and in vivo. MATERIALS AND METHODS: The active components of CYW were identified using HPLC-QTOF-MS/MS in combination with the GNPS molecular networking and network pharmacology. In vitro studies were performed in the RAW264.7/GES-1 cell coculture system. In vivo study, mice were treated with CYW (0.31, 0.63, and 3.14 g/kg BW, orally) for 14 days, followed by a single oral dose of ethanol (10 mL/kg BW) to induce gastric injury. The biochemical, inflammation and oxidative stress markers were analyzed using commercial kits. Histopathology was used to assess the degree of gastric injury. Gene and protein expressions were studied using RT-qPCR and western blotting, respectively. RESULTS: CYW significantly restored the levels of SOD, GPx and CAT, and reduced the MDA content. Further analyses showed that CYW significantly alleviated the gastric oxidative stress by inhibiting the inflammation via decreasing p-NF-κB and p-IκB-α expression levels and inhibiting the generation of IL-6, TNF-α, and IL-1ß. At the same time, the fraction remarkably upregulated Bcl-2, downregulated Bax and increased growth factor secretion, thereby prevented gastric mucous cell. Besides, The combination of HPLC-QTOF-MS/MS, GNPS molecular networking analysis, and network pharmacology demonstrated that linoleic acid, 3-acetyl-11-keto-beta-boswellic acid, adenosine, aminocaproic acid, tyramine, DL-tryptophan, cycloleucine, lactulose, melibiose, alpha-beta-trehalose, and sucrose would be the main active compounds of CYW against ethanol-induced gastric injury. CONCLUSION: This study showed that CYW is potentially rich source of anti-oxidant and anti-inflammatory bioactive compounds. It showed efficacy against ethanol-induced gastric injury by inhibiting inflammation, oxidative stress, and apoptosis in the stomach. The results of the current work indicate that Dioscoreae Rhizoma could be utilized as a type of natural resource for production of new medicine and functional foods to prevent and/or ameliorate ethanol-induced gastric injury.

Resistant starch from yam: Preparation, nutrition, properties and applications in the food sector.

Yam is a significant staple food and starch source, particularly in tropical and subtropical regions, holding the fourth position among the world's top ten tuber crops. Yam tubers are rich in essential nutrients and a diverse range of beneficial plant compounds, which contribute to their multifaceted beneficial functions. Furthermore, the abundant starch and resistant starch (RS) content in yam can fulfil the market demand for RS. The inherent and modified properties of yam starch and RS make them versatile ingredients for a wide range of food products, with the potential to become one of the most cost-effective raw materials in the food industry. In recent years, research on yam RS has experienced progressive expansion. This article provides a comprehensive summary of the latest research findings on yam starch and its RS, elucidating the feasibility of commercial RS production and the technology's impact on the physical and chemical properties of starch. Yam has emerged as a promising reservoir of tuber starch for sustainable RS production, with thermal, chemical, enzymatic and combination treatments proving to be effective manufacturing procedures for RS. The adaptability of yam RS allows for a wide range of food applications.

Genome-wide association analysis and transgenic characterization for amylose content regulating gene in tuber of Dioscorea zingiberensis.

BACKGROUND: Amylose, a prebiotic found in yams is known to be beneficial for the gut microflora and is particularly advantageous for diabetic patients' diet. However, the genetic machinery underlying amylose production remains elusive. A comprehensive characterization of the genetic basis of amylose content in yam tubers is a prerequisite for accelerating the genetic engineering of yams with respect to amylose content variation. RESULTS: To uncover the genetic variants underlying variation in amylose content, we evaluated amylose content in freshly harvested tubers from 150 accessions of Dioscorea zingibensis. With 30,000 high-quality single nucleotide polymorphisms (SNP), we performed a genome-wide association analysis (GWAS). The population structure analysis classified the D. zingiberensis accessions into three groups. A total of 115 significant loci were detected on four chromosomes. Of these, 112 significant SNPs (log10(p) = 5, q-value < 0.004) were clustered in a narrow window on the chromosome 6 (chr6). The peak SNP at the position 75,609,202 on chr6 could explain 63.15% of amylose variation in the population and fell into the first exon of the ADP-glucose pyrophosphorylase (AGPase) small subunit gene, causing a non-synonymous modification of the resulting protein sequence. Allele segregation analysis showed that accessions with the rare G allele had a higher amylose content than those harboring the common A allele. However, AGPase, a key enzyme precursor of amylose biosynthesis, was not expressed differentially between accessions with A and G alleles. Overexpression of the two variants of AGPase in Arabidopsis thaliana resulted in a significantly higher amylose content in lines transformed with the AGPase-G allele. CONCLUSIONS: Overall, this study showed that a major genetic variant in AGPase probably enhances the enzyme activity leading to high amylose content in D. zingiberensis tuber. The results provide valuable insights for the development of amylose-enriched genotypes.

A high-permeability method for extracting purple yam saponins based on ultrasonic-assisted natural deep eutectic solvent.

The extraction of active ingredients from traditional Chinese medicine has received considerable attentions. In this study, 16 kinds of natural deep eutectic solvent (NADES) with ultrasonic were selected to extract saponins from purple yam root and the extraction mechanism was investigated. The results showed that chloride/acrylic acid (1:2; n/n) had the highest extraction yield for saponins. The optimal extraction process parameters were 24% water content, 20 mL/g liquid-solid ratio, and ultrasonic extraction for 85 min (81 °C, 600 W). The extraction rate (ER) of purple yam saponins was 0.935%, close to the fitted result of 96.5 mg/g. Molecular dynamics simulations and FT-IR results showed that the NADES may extract the saponin constituents from purple yam through hydrogen bonding. Compared with traditional extraction methods and molecularly imprinted polymer methods, NADES has a higher ER and lower cost (1.53 $/g), which provides a reference for subsequent industrial quantitative production.

Identification of genetic variants controlling diosgenin content in Dioscorea zingiberensis tuber by genome-wide association study.

BACKGROUND: Diosgenin is an important steroidal precursor renowned for its diverse medicinal uses. It is predominantly sourced from Dioscorea species, particularly Dioscorea zingiberensis. Dioscorea zingiberensis has an ability to accumulate 2-16% diosgenin in its rhizomes. In this study, a diverse population of 180 D. zingiberensis accessions was used to evaluate the genomic regions associated with diosgenin biosynthesis by the genome wide association study approach (GWAS). RESULTS: The whole population was characterized for diosgenin contents from tubers by gas chromatography mass spectrometry. The individuals were genotyped by the genotyping-by-sequencing approach and 10,000 high-quality SNP markers were extracted for the GWAS. The highest significant marker-trait-association was observed as an SNP transversion (G to T) on chromosome 10, with 64% phenotypic variance explained. The SNP was located in the promoter region of CYP94D144 which is a member of P450 gene family involved in the independent biosynthesis of diosgenin from cholesterol. The transcription factor (TF) binding site enrichment analysis of the promoter region of CYP94D144 revealed NAC TF as a potential regulator. The results were further validated through expression profiling by qRT-PCR, and the comparison of high and low diosgenin producing hybrids obtained from a bi-parental population. CONCLUSIONS: This study not only enhanced the understanding of the genetic basis of diosgenin biosynthesis but also serves as a valuable reference for future genomic investigations on CYP94D144, with the aim of augmenting diosgenin production in yam tubers.