Application of carbon nanomaterial in abelmoschus manihot planting

Abstract

The invention discloses application of a carbon nanomaterial in abelmoschus manihot planting. According to the present invention, according to the prior art, chitosan with rich reserves in nature is adopted as a carbon source to prepare carbon dots CDs by using a one-step hydrothermal method, and urea is added to the raw material to form nitrogen-doped CDs; when the CDs act on the growing abelmoschus manihot through foliage spraying or root irrigation, not only can the increase of the flower weight be effectively promoted and the flower yield be improved, but also the content of effective components in the flower can be effectively improved. Therefore, when the CDs provided by the invention are applied to abelmoschus manihot planting, the yield of the abelmoschus manihot can be increased, and the medicinal quality of the abelmoschus manihot can also be improved.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterial applications, and relates to the application of carbon nanomaterials in agriculture, specifically to the application of carbon nanomaterials in the cultivation of okra. Background Technology

[0002] Okra capsules are mainly used for the treatment of chronic kidney disease. They have the effects of reducing proteinuria, protecting kidney function, anti-inflammatory effects, diuresis and swelling reduction, and improving symptoms.

[0003] Huangshukui capsules are a single-ingredient traditional Chinese medicine preparation, with Huangshukui flower as the main ingredient. The chemical components of Huangshukui flower are mainly flavonoids, including hyperoside, quercetin, myricetin, and quercetin-3-glucoside, which can effectively inhibit renal immune responses, reduce proteinuria, improve clinical symptoms of chronic nephritis, and effectively protect renal tubular epithelial cells, thus mitigating the progression of kidney disease. In the Chinese Pharmacopoeia, the Huangshukui flower content in Huangshukui capsules is calculated as hyperoside.

[0004] The cultivation of Chinese medicinal herbs faces uncontrollable factors such as environmental changes and pest and disease control, and the market price of medicinal materials fluctuates greatly, which may affect the consistency of finished product batches and market supply. The "Good Manufacturing Practice for Traditional Chinese Medicine" issued by the National Medical Products Administration also requires ensuring "batch consistency and traceability of medicinal materials." Given this technological gap and policy window, there is an urgent need to expand the profitability of okra cultivation through new technologies.

[0005] Carbon dots (CDs) are a novel class of carbon nanomaterials that have attracted considerable attention due to their good water solubility, low toxicity, excellent optical properties, and moderate stability. They can be used in environmental monitoring, food analysis, biochemical analysis, drug detection, disease diagnosis, and bioimaging. Carbon sources for CD preparation are abundant; organic molecules, natural biomass, and other carbon-containing materials can all be used. Current techniques often use chitosan, which is abundant in nature, as a carbon source in a one-step hydrothermal method to prepare carbon dot CDs (Reference: Preparation and Detection Application of Chitosan-Derived Carbon Dots, Master's Thesis, 2022).

[0006] There are currently no reports on the application of CDs in okra cultivation. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of the prior art and provide an application of carbon nanomaterials in the cultivation of okra.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution:

[0009] The application of a carbon nanomaterial in improving the quality and medicinal properties of okra flowers during okra cultivation; wherein the carbon nanomaterial is prepared by a hydrothermal method using chitosan and urea as raw materials.

[0010] Preferably, the mass ratio of chitosan to urea is 1:2 to 1:6.

[0011] Preferably, the temperature of the hydrothermal reaction is 180~220℃.

[0012] Preferably, the hydrothermal reaction time is 4 to 12 hours.

[0013] Preferably, improving the medicinal quality of okra flowers refers to improving the medicinal active ingredients in okra flowers.

[0014] More preferably, the medicinal active ingredient includes total flavonoids.

[0015] More preferably, the pharmaceutically active ingredient includes hyperoside.

[0016] More preferably, the pharmaceutically active ingredient includes isoquercitrin.

[0017] Beneficial effects:

[0018] This invention utilizes chitosan, which is abundant in nature, as a carbon source to prepare carbon dot CDs via a one-step hydrothermal method (Reference: Preparation and Detection Application of Chitosan-Derived Carbon Dots, Master's Thesis, 2022). Urea is also added to the raw materials to form nitrogen-doped CDs. When these CDs are applied to growing okra through foliar spraying or root irrigation, they not only effectively promote flower weight and increase flower yield but also effectively increase the content of active ingredients in the flowers. Therefore, applying the CDs provided by this invention to okra cultivation can both increase okra flower yield and improve the medicinal quality of okra flowers. Attached Figure Description

[0019] Figure 1 The effect of different concentrations of CDs on the flower weight of Okra. Detailed Implementation

[0020] The substantive content of the present invention will be described in detail below with reference to specific embodiments. However, those skilled in the art should know that the scope of protection of the present invention should not be limited to these specific embodiments.

[0021] Example 1: Preparation of CDs (chitosan-urea mass ratio 1:4, hydrothermal reaction at 200℃ for 4 h)

[0022] 1. Precursor formulation

[0023] Add 0.2g of chitosan powder and 0.8g of urea to a 50mL beaker, and while stirring at room temperature, add 20mL of deionized water to form a milky white suspension.

[0024] 2. Homogenization

[0025] The suspension was placed in an ultrasonic cleaner with a frequency of 40 kHz and a power of 250 W and continuously sonicated for 20 minutes until the solution was homogeneous, transparent and free of obvious bubbles.

[0026] 3. Hydrothermal reaction

[0027] The above solution was transferred into a 50mL high-pressure reactor lined with PTFE and stainless steel, with a filling degree of ≤80%. After tightening the seal, it was placed in a preheated oven at 200℃ and reacted at a constant temperature for 4 hours.

[0028] 4. Post-processing

[0029] After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The brownish-yellow supernatant was collected after opening the vessel. Large particulate impurities were removed by vacuum filtration using a 0.22 μm aqueous filter membrane. The mixture was then dialyzed in deionized water for 12 h using a 500 Da dialysis bag (with water changed every 2 h). Finally, a clear chitosan-urea carbon dot mother liquor (denoted as CDs-1) was obtained and stored at 4 °C in the dark.

[0030] 5. Concentration determination

[0031] Take an appropriate amount of carbon dot mother liquor, dilute it with deionized water to a certain factor, and measure its absorbance value at 280 nm. Calculate the accurate concentration of carbon dots in the mother liquor based on the pre-established carbon dot concentration-absorbance standard curve.

[0032] Example 2: Preparation of CDs (chitosan-urea mass ratio 1:6, hydrothermal reaction at 180℃ for 12 h)

[0033] 1. Precursor formulation

[0034] Add 0.1g of chitosan powder and 0.6g of urea to a 50mL beaker, and while stirring at room temperature, add 20mL of deionized water to form a milky white suspension.

[0035] 2. Homogenization

[0036] The suspension was placed in an ultrasonic cleaner with a frequency of 40 kHz and a power of 250 W and continuously sonicated for 20 minutes until the solution was homogeneous, transparent and free of obvious bubbles.

[0037] 3. Hydrothermal reaction

[0038] The above solution was transferred into a 50mL high-pressure reactor lined with polytetrafluoroethylene and stainless steel, with a filling degree of ≤80%. After tightening the seal, the reactor was placed in a preheated oven at 180°C and reacted at a constant temperature for 12 hours.

[0039] 4. Post-processing

[0040] The solution was filtered and dialyzed using the same method as in Example 1 to obtain a clear chitosan-urea carbon dot mother liquor (denoted as CDs-2). The concentration was measured and the solution was stored at 4°C in the dark.

[0041] Example 3: Preparation of CDs (chitosan-urea mass ratio 1:2, hydrothermal reaction 220℃, 6h)

[0042] 1. Precursor formulation

[0043] Add 0.3g of chitosan powder and 0.6g of urea to a 50mL beaker, and while stirring at room temperature, add 20mL of deionized water to form a milky white suspension.

[0044] 2. Homogenization

[0045] The suspension was placed in an ultrasonic cleaner with a frequency of 40 kHz and a power of 250 W and continuously sonicated for 20 minutes until the solution was homogeneous, transparent and free of obvious bubbles.

[0046] 3. Hydrothermal reaction

[0047] Transfer the above solution into a 50mL polytetrafluoroethylene-lined stainless steel high-pressure reactor, with a filling degree ≤80%. After tightening the seal, place it in a preheated 220℃ oven and react at a constant temperature for 6 hours.

[0048] 4. Post-processing

[0049] The solution was filtered and dialyzed using the same method as in Example 1 to obtain a clear chitosan-urea carbon dot mother liquor (denoted as CDs-3). The concentration was determined and the solution was stored at 4°C in the dark.

[0050] Example 4: Effects of CDs on the growth and active ingredient content of Hibiscus syriacus flowers

[0051] This embodiment investigates the effects of different concentrations of carbon dots on the growth and active ingredient content of okra flowers, using CDs-1 prepared in Example 1 as an example (CDs-2 and CDs-3 have similar activities). The experiment was designed with 5 groups, including one control group and 4 experimental groups with different concentrations of CDs (20, 50, 100, and 150 μg / mL). Foliar spraying and root irrigation were performed during the seedling stage, vegetative growth stage, and budding and flowering stage of okra flowers, respectively. Specific application times and methods of CDs are shown in Table 1.

[0052] Table 1. Timing and Method of CDs Application During Okra Cultivation

[0053]

[0054] 1. Effects of carbon dots on the growth of Hibiscus syriacus flowers

[0055] The results are as follows Figure 1 As shown. (Through) Figure 1 As shown in 'a', compared with the control group, the flower weight of experimental groups 1-4 was effectively increased, with a clear upward trend. In particular, the flower weight of experimental group 3 was approximately 138% higher than that of the control group. A comparison of actual specimens of the control group and experimental group 3 (e.g., hibiscus flowers) is provided. Figure 1 As shown in Figure b. The experimental results indicate that the CDs provided by this invention can effectively promote the growth of okra flowers and increase the yield of okra flowers.

[0056] 2. Effect of carbon dots on the content of active ingredients in okra flowers

[0057] To explore the effects of carbon dots on the active components in *Abelmoschus manihot* flowers, a high-performance liquid chromatography (HPLC) method was established to detect hyperoside and isoquercitrin in *Abelmoschus manihot* flowers, referring to the Chinese Pharmacopoeia and relevant literature. Total flavonoids in *Abelmoschus manihot* flowers were determined by spectrophotometry. The experimental results are shown in Table 2. Compared with the control group, at a concentration of 100 μg / mL CDs, the total flavonoid content in a single flower increased by 170%, the accumulation of hyperoside in a single flower increased by 148%, and the accumulation of isoquercitrin also increased by 174%. These experimental results indicate that the CDs provided by this invention can effectively promote the biosynthesis of secondary metabolites in *Abelmoschus manihot* flowers, thereby improving the medicinal value and market competitiveness of *Abelmoschus manihot* flowers.

[0058] Table 2

[0059]

[0060] In summary, this invention utilizes chitosan, which is abundant in nature, as a carbon source to prepare carbon dot CDs via a one-step hydrothermal method (Reference: Preparation and Detection Application of Chitosan-Derived Carbon Dots, Master's Thesis, 2022). Urea is also added to the raw materials to form nitrogen-doped CDs. When these CDs are applied to growing okra through foliar spraying or root irrigation, they not only effectively promote flower weight and increase flower yield but also effectively increase the content of active ingredients in the flowers. Therefore, applying the CDs provided by this invention to okra cultivation can both increase okra flower yield and improve the medicinal quality of okra flowers.

[0061] The purpose of the above embodiments is to specifically illustrate the substantive content of the present invention, but those skilled in the art should know that the scope of protection of the present invention should not be limited to the specific embodiments.

Claims

1. The application of a carbon nanomaterial in improving the quality and medicinal properties of okra flowers during cultivation; wherein, The carbon nanomaterials were prepared using chitosan and urea as raw materials via a hydrothermal method.

2. The application according to claim 1, characterized in that: The mass ratio of chitosan to urea is 1:2 to 1:

6.

3. The application according to claim 1, characterized in that: The hydrothermal reaction temperature is 180~220℃.

4. The application according to claim 1, characterized in that: The hydrothermal reaction takes 4 to 12 hours.

5. The application according to claim 1, characterized in that: Improving the medicinal quality of okra flowers refers to enhancing the medicinal active ingredients in okra flowers.

6. The application according to claim 5, characterized in that: The active pharmaceutical ingredients include total flavonoids.

7. The application according to claim 5, characterized in that: The active pharmaceutical ingredient includes hyperoside.

8. The application according to claim 5, characterized in that: The active pharmaceutical ingredient includes isoquercitrin.

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