A method for simultaneously separating multiple active ingredients from a dianthus superbus l. essential oil

Abstract

This invention discloses a method for simultaneously separating multiple active ingredients from *Pterocarya stenoptera* essential oil, belonging to the field of natural product separation and purification technology. The invention includes the following steps: (1) sequentially subjecting *Pterocarya stenoptera* to steam distillation and molecular distillation to obtain *Pterocarya stenoptera* essential oil; (2) subjecting the *Pterocarya stenoptera* essential oil to dehydration and degassing to obtain pretreated essential oil; (3) subjecting the pretreated essential oil to two-stage molecular distillation to obtain fraction 1, fraction 2, and residual liquid; (4) subjecting fraction 1, fraction 2, and residual liquid to vacuum precision distillation to simultaneously separate multiple active ingredients from *Pterocarya stenoptera* essential oil. This invention features a green and environmentally friendly process, no organic solvent residue, low energy consumption, and strong controllability, enabling continuous industrial production. The purity of each monomer product is ≥98%, with the main component, methyl salicylate, having a purity ≥99%. This fully exploits the resource value of *Pterocarya stenoptera* essential oil and significantly increases the added value of the product.

Description

Technical Field

[0001] This invention relates to the field of natural product separation and purification technology, and in particular to a method for simultaneously separating multiple active ingredients from Yunnan white pearl essential oil. Background Technology

[0002] Gaultheria leucocarpa Bl. var. yunnanensis (Franch.) TZ Hsu, commonly known as Yunnan white pearl, is an evergreen shrub belonging to the genus Gaultheria in the family Ericaceae. It is mainly produced in southwestern my country, including Yunnan, Guizhou, Sichuan, and Guangxi provinces, and is a distinctive Chinese medicinal and edible plant. The essential oil obtained from its branches and leaves through steam distillation, also known as winter green oil, is traditionally used for dispelling wind and dampness, promoting blood circulation, and relieving inflammation and pain. It is also an important raw material in the daily chemical, fragrance, and pharmaceutical industries.

[0003] In existing technologies, the development and utilization of *Phyllostachys edulis* essential oil is highly focused on its main component, methyl salicylate. Related patents and literature primarily focus on the extraction and purification of methyl salicylate, completely ignoring other trace high-value components in the essential oil. In fact, besides methyl salicylate, *Phyllostachys edulis* essential oil also contains abundant terpenes, alcohols, esters, and ketones, including α-pinene, β-pinene, carenes, linalool, leaf alcohol, ionones, β-caryophyllene, and salicylic acid leaf esters. Among them, pinenes and carenes are important organic synthesis intermediates, widely used in fragrances, resins, and pharmaceuticals; leaf alcohol, trans-3-hexen-1-ol, and linalool are internationally recognized natural fragrances, widely used in daily chemicals and food flavoring; ionones are core intermediates in the synthesis of vitamins A and E7, and also have excellent fixative properties; β-caryophyllene has significant anti-inflammatory, analgesic, and antibacterial activities, and is a popular raw material in the pharmaceutical and daily chemical fields; salicylic acid leaf alcohol esters combine the soothing activity of salicylic acid esters with the refreshing fragrance of leaf alcohol, making them a characteristic raw material for high-end perfumes and skincare products.

[0004] Existing technologies cannot achieve the simultaneous separation of the aforementioned multiple components. The core drawbacks are: 1. They primarily employ direct distillation processes, which involve complex raw material components with a wide boiling point range, requiring multiple distillations, resulting in high energy consumption and long cycles. Furthermore, heat-sensitive components (such as unsaturated alcohols and esters) are prone to decomposition and oxidation at high temperatures, leading to poor product quality. 2. For trace components with similar boiling points (such as α / β-ionone), conventional distillation cannot achieve effective separation, making it difficult to meet purity standards. 3. Some processes utilize methods such as silica gel column chromatography and preparative liquid chromatography, using large amounts of organic solvents, posing a risk of solvent residue and hindering continuous industrial production. 4. Existing processes can only separate 7-9 components, with a large amount of high-value-added trace components discharged with the waste liquid, causing severe resource waste and extremely low product added value.

[0005] Therefore, developing a green, environmentally friendly, industrially scalable method that can simultaneously separate multiple high-purity active monomers from Yunnan white pearl essential oil is of significant economic value and practical importance for the full-value utilization of Yunnan white pearl resources. Summary of the Invention

[0006] The purpose of this invention is to provide a method for simultaneously separating multiple active ingredients from *Pterocarya stenoptera* essential oil. This invention uses steam-distilled *Pterocarya stenoptera* essential oil as raw material. After drying, dehydration, and vacuum degassing pretreatment, a two-stage scraped-film molecular distillation process is used for pre-fractionation, precisely dividing the raw material into three fractions according to boiling point range: light component fraction 1, medium component fraction 2, and heavy component residue. Then, based on the component characteristics of each fraction, high-efficiency vacuum precision distillation with different parameters is used for stepwise separation, all under nitrogen protection. Ultimately, 11 high-purity monomeric active ingredients are obtained simultaneously. This invention's process is green and environmentally friendly, leaves no organic solvent residue, has low energy consumption, and is highly controllable, enabling continuous industrial production. The purity of each monomeric product is ≥98%, with the main component, methyl salicylate, having a purity ≥99%. This fully exploits the resource value of *Pterocarya stenoptera* essential oil and significantly increases the product's added value.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for simultaneously separating multiple active ingredients from Yunnan white pearl essential oil, comprising the following steps: (1) Yunnan white pearl was subjected to steam distillation and molecular distillation in sequence to obtain Yunnan white pearl essential oil; (2) Dehydrate and degas the Yunnan white pearl essential oil to obtain pretreated essential oil; (3) The pretreated essential oil was subjected to two-stage molecular distillation to obtain fraction 1, fraction 2 and residual liquid; (4) By performing vacuum distillation on fraction 1, fraction 2 and the residue, multiple active ingredients can be separated from Yunnan white pearl essential oil simultaneously. The various active ingredients include: α-pinene, β-pinene, 3-carene, trans-3-hexen-1-ol, leaf alcohol, linalool, methyl salicylate, α-ionone, β-ionone, β-caryophyllene, and salicylic acid leaf alcohol ester.

[0008] Preferably, the conditions for steam distillation are: temperature 95~110℃, time 1~3h, and pressure 0.01~0.07MPa; wherein the mass ratio of Yunnan white pearl to distilled water during steam distillation is 1:3~6; the conditions for molecular distillation are: temperature 60~90℃, vacuum degree 100~300Pa, feed rate 2~7mL / min, scraper rotation speed 100~200rpm, and cooling temperature 5~10℃.

[0009] Preferably, the dehydration and degassing method is as follows: place Yunnan white pearl essential oil at 40~50℃ and absolute pressure of 8~12kPa to dehydrate until the moisture content is ≤0.05% to obtain dehydrated essential oil, and degas the dehydrated essential oil under the same conditions for 30~60min.

[0010] Preferably, a scraped-film molecular distillation apparatus is used for secondary molecular distillation in step (3); the specific method of the secondary molecular distillation is as follows: First-stage molecular distillation: Evaporation temperature 60~80℃, condensation surface temperature 0~5℃, system absolute pressure 0.1~0.5Pa, scraper rotation speed 150~300rpm, feed rate 1~3mL / min, collect the light components at the top of the column to obtain fraction 1, and the heavy components at the bottom of the column enter the second-stage molecular distillation; Second-stage molecular distillation: Evaporation temperature 100~120℃, condensation surface temperature 10~15℃, system absolute pressure 0.1~0.3Pa, scraper rotation speed 200~350rpm, feed rate 0.8~2mL / min, collect the light components at the top of the column to obtain fraction 2, and the heavy components at the bottom of the column are the residue.

[0011] As a preferred option, when fraction 1 is subjected to vacuum precision distillation in step (4), the distillation column is equipped with CY-type metal wire mesh corrugated packing, with a theoretical number of 80~120 plates. The distillation parameters are: system absolute pressure 5~10kPa, column bottom temperature 70~95℃, column top condensation temperature 0~5℃. After the total reflux is stabilized for 2~4h, each monomer component is extracted step by step according to the gradient reflux ratio.

[0012] Preferably, the gradient reflux step-by-step sampling is as follows: Set the reflux ratio to 30-50:1 to extract α-pinene; adjust the reflux ratio to 40-60:1 to extract β-pinene; adjust the reflux ratio to 50-70:1 to extract 3-carene; adjust the reflux ratio to 30-50:1 to extract trans-3-hexen-1-ol; adjust the reflux ratio to 20-40:1 to extract leaf alcohol.

[0013] As a preferred option, when fraction 2 is subjected to vacuum precision distillation in step (4), the distillation column is equipped with BX type metal wire mesh corrugated packing, with a theoretical number of 100~150 plates. The distillation parameters are: system absolute pressure 1~3kPa, column bottom temperature 90~120℃, column top condensing temperature 5~10℃. After the total reflux is stabilized for 3~5h, each monomer component is collected step by step according to the gradient reflux ratio.

[0014] Preferably, the gradient reflux step-by-step sampling is as follows: Set the reflux ratio to 20-30:1 to extract linalool; adjust the reflux ratio to 15-25:1 to extract methyl salicylate; adjust the reflux ratio to 60-80:1 to extract α-ionone; adjust the reflux ratio to 70-90:1 to extract β-ionone.

[0015] As a preferred option, when the residual liquid in step (4) is subjected to vacuum precision distillation, the distillation column is equipped with θ-ring metal structured packing, with a theoretical number of 60 to 80 plates. The distillation parameters are: system absolute pressure 0.5 to 1 kPa, column bottom temperature 120 to 150°C, column top condensation temperature 10 to 15°C. After the total reflux is stabilized for 2 to 3 hours, each monomer component is collected stepwise according to the gradient reflux ratio.

[0016] Preferably, the gradient reflux step-by-step sampling is as follows: Set the reflux ratio to 10~20:1 to extract β-caryophyllene; adjust the reflux ratio to 15~25:1 to extract salicylic acid leaf ester.

[0017] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses a two-step method of steam distillation-molecular distillation to prepare Yunnan white pearl essential oil. Compared with the conventional single distillation process, it effectively removes impurities and ineffective components from Yunnan white pearl crude oil, and significantly improves the purity and effective component content of Yunnan white pearl essential oil.

[0018] (2) This invention is the first to achieve the simultaneous separation of 11 high-purity active monomer components from Yunnan white pearl essential oil, covering almost all high-value-added components in the essential oil, and completely changing the current situation of resource waste where existing technologies only utilize methyl salicylate and other components are discharged with waste liquid.

[0019] (3) The present invention adopts the core process of “molecular distillation pre-fractionation + segmented vacuum precision distillation”. First, the 11 components are accurately divided into 3 fractions according to the boiling point range. Then, the distillation parameters are customized according to the component characteristics of each fraction. This completely avoids the mutual interference of direct distillation of all components, greatly reduces the separation difficulty, and shortens the production cycle.

[0020] (4) For fraction 1, which is the most difficult to separate, the present invention selects CY-type metal wire mesh corrugated packing with the highest separation efficiency to provide basic mass transfer conditions for the separation of near-boiling-point components; for fraction 2, which is highly heat-sensitive, BX-type metal wire mesh corrugated packing with the lowest pressure drop and liquid holdup is selected to balance separation efficiency and the stability of heat-sensitive components; for the high-viscosity, high-boiling-point residue, θ-ring packing with strong anti-clogging properties and high throughput is selected to ensure the stable separation of heavy components under high vacuum. Gradient matching is performed for the separation difficulty of different fractions. By setting the theoretical plate number in combination with the separation efficiency of the packing, the separation effect of near-boiling-point difficult-to-separate components is guaranteed, while avoiding problems such as large equipment investment, long material residence time, degradation of heat-sensitive components, and increased energy consumption caused by excessively high theoretical plate number. To address the varying separation challenges of different components, a gradient reflux ratio dynamic control strategy is employed. This involves stabilizing the gas-liquid balance within the column using full reflux, first purifying the top component with a high reflux ratio, and then switching to a low reflux ratio for continuous extraction once the target component's purity meets the requirements. This approach ensures product purity while minimizing energy consumption and shortening material heating time, achieving synergistic optimization of purity, recovery rate, and energy consumption. This invention, targeting the characteristics of 11 target components in Yunnan white pearl oil, establishes for the first time a synergistic separation system based on "precise selection of packing type - gradient matching of theoretical plate number - dynamic control of reflux ratio," solving the core pain point of difficult separation of near-boiling point isomers in existing technologies.

[0021] (5) The entire separation process of this invention does not use any organic solvents, and separation is achieved solely through physical distillation. There is no wastewater or waste solvent discharge, making it green and environmentally friendly, and the product has no solvent residue. This invention uses nitrogen protection throughout the process, combined with high vacuum and low temperature distillation technology, which effectively avoids the oxidation, decomposition, and isomerization of heat-sensitive components such as unsaturated terpenes, alcohols, and esters. The scraped-film molecular distillation and vacuum precision distillation equipment used in this invention are both mature industrial-grade equipment with stable process parameters and strong controllability, enabling continuous production. This solves the problem that existing column chromatography and preparative liquid chromatography cannot be scaled up industrially, and has good prospects for industrial application. Attached Figure Description

[0022] Figure 1 This is the mass spectrum of the methyl salicylate sample; Figure 2 The mass spectra of methyl salicylate standard and the mass spectra of methyl salicylate are compared to the difference spectrum. Figure 3 Mass spectrum of salicylic acid leaf alcohol ester sample; Figure 4 The difference spectrum between the standard mass spectra of salicylate leaf ester and the mass spectra of salicylate leaf ester. Figure 5 This is the mass spectrum of the β-caryophyllene sample; Figure 6 The difference spectrum between the standard mass spectrum of β-caryophyllene and the mass spectrum matching of β-caryophyllene. Figure 7 Mass spectrum of α-pinene sample; Figure 8 The difference spectrum between the standard mass spectrum of α-pinene and the mass spectrum of α-pinene is shown. Figure 9 This is the mass spectrum of the β-pinene sample; Figure 10 The difference spectrum between the standard mass spectrum of β-pinene and the mass spectrum of β-pinene is shown. Figure 11 Mass spectrum of 3-carene sample; Figure 12 The difference spectrum between the standard mass spectrum of 3-carene and the mass spectrum of 3-carene is shown. Figure 13 This is the mass spectrum of the linalool sample; Figure 14 The difference spectrum between the standard mass spectrum of linalool and the mass spectrum of linalool. Figure 15 This is the mass spectrum of the leaf alcohol sample; Figure 16 The difference spectrum between the standard quality spectrum of leaf alcohol and the mass spectrum of leaf alcohol; Figure 17 This is the mass spectrum of the trans-3-hexen-1-ol sample; Figure 18 The mass spectra of trans-3-hexen-1-ol and the mass spectra of trans-3-hexen-1-ol are shown as the difference spectra when matched. Figure 19 This is the mass spectrum of the α-ionone sample; Figure 20 The difference spectrum between the standard mass spectra of α-ionone and the mass spectra of α-ionone. Figure 21 This is the mass spectrum of the β-ionone sample; Figure 22 The difference spectrum between the standard mass spectra of β-ionone and the mass spectra of β-ionone. Detailed Implementation

[0023] This invention provides a method for simultaneously separating multiple active ingredients from Yunnan white pearl essential oil, comprising the following steps: (1) Yunnan white pearl was subjected to steam distillation and molecular distillation in sequence to obtain Yunnan white pearl essential oil; (2) Dehydrate and degas the Yunnan white pearl essential oil to obtain pretreated essential oil; (3) The pretreated essential oil was subjected to two-stage molecular distillation to obtain fraction 1, fraction 2 and residual liquid; (4) By performing vacuum distillation on fraction 1, fraction 2 and the residue, multiple active ingredients can be separated from Yunnan white pearl essential oil simultaneously. The various active ingredients include: α-pinene, β-pinene, 3-carene, trans-3-hexen-1-ol, leaf alcohol, linalool, methyl salicylate, α-ionone, β-ionone, β-caryophyllene, and salicylic acid leaf alcohol ester.

[0024] In this invention, the conditions for steam distillation are as follows: temperature 95~110℃, preferably 98~105℃, more preferably 100℃; time 1~3h, preferably 1.2~2h, more preferably 1.5h; pressure 0.01~0.07MPa, preferably 0.02~0.05MPa, more preferably 0.03MPa; wherein the mass ratio of Yunnan white pearl to distilled water during steam distillation is 1:3~6, preferably 1:4~5.5, more preferably 1:5; the molecular distillation... The conditions are as follows: temperature 60~90℃, preferably 70~85℃, more preferably 80℃; vacuum degree 100~300Pa, preferably 150~200Pa, more preferably 180Pa; feed rate 2~7mL / min, preferably 3~6mL / min, more preferably 5mL / min; scraper rotation speed 100~200rpm, preferably 120~180rpm, more preferably 160rpm; cooling temperature 5~10℃, preferably 6~9℃, more preferably 8℃.

[0025] In this invention, the dehydration and degassing method is as follows: Yunnan white pearl essential oil is placed in a vacuum environment at 40-50°C and an absolute pressure of 8-12 kPa to dehydrate until the moisture content is ≤0.05%, obtaining dehydrated essential oil. The dehydrated essential oil is then degassed under the same conditions for 30-60 minutes. The temperature of the vacuum environment is preferably 42-48°C, more preferably 45°C. The absolute pressure of the vacuum environment is preferably 9-11 kPa, more preferably 10 kPa. The degassing time is preferably 40-50 minutes, more preferably 45 minutes.

[0026] In this invention, a scraped-film molecular distillation apparatus is used for secondary molecular distillation in step (3); preferably, the molecular distillation apparatus is preheated before feeding, and the specific method of the secondary molecular distillation is as follows: First-stage molecular distillation: Evaporation temperature 60~80℃, preferably 65~75℃, more preferably 70℃; condensation surface temperature 0~5℃, preferably 1~3℃, more preferably 2℃; system absolute pressure 0.1~0.5Pa, preferably 0.2~0.4Pa, more preferably 0.3Pa; scraper rotation speed 150~300rpm, preferably 180~250rpm, more preferably 200rpm; feed rate 1~3mL / min, preferably 1.5~2.5mL / min, more preferably 2mL / min; collect the light components at the top of the column to obtain fraction 1; the heavy components at the bottom of the column enter the second-stage molecular distillation. Second-stage molecular distillation: Evaporation temperature 100~120℃, preferably 105~115℃, more preferably 110℃; condensation surface temperature 10~15℃, preferably 11~13℃, more preferably 12℃; system absolute pressure 0.1~0.3Pa, preferably 0.15~0.25Pa, more preferably 0.2Pa; scraper rotation speed 200~350rpm, preferably 230~300rpm, more preferably 250rpm; feed rate 0.8~2mL / min, preferably 1~1.8mL / min, more preferably 1.5mL / min; collect the light components at the top of the column to obtain fraction 2, and the heavy components at the bottom of the column are the residue.

[0027] In this invention, when fraction 1 is subjected to vacuum precision distillation in step (4), the distillation column adopts CY-type metal wire mesh corrugated packing, with a theoretical number of 80~120 plates, preferably 90~110 plates, and more preferably 100 plates. The distillation parameters are: system absolute pressure 5~10 kPa, preferably 7~9 kPa, and more preferably 8 kPa; column bottom temperature 70~95℃, preferably 80~85℃, and more preferably 82℃; column top condensation temperature 0~5℃, preferably 1~3℃, and more preferably 2℃; after total reflux stabilization for 2~4 h, preferably 2.5~3.5 h, and more preferably 3 h, each monomer component is collected stepwise according to the gradient reflux ratio, wherein the monomer components include α-pinene, β-pinene, 3-carene, trans-3-hexen-1-ol, and leaf alcohol.

[0028] In this invention, the gradient backflow stepwise sampling is as follows: Set the reflux ratio to 30-50:1 to extract α-pinene, preferably 35-45:1, more preferably 40:1; adjust the reflux ratio to 40-60:1 to extract β-pinene, preferably 45-55:1, more preferably 50:1; adjust the reflux ratio to 50-70:1 to extract 3-carene, preferably 55-65:1, more preferably 60:1; adjust the reflux ratio to 30-50:1 to extract trans-3-hexen-1-ol, preferably 35-45:1, more preferably 40:1; adjust the reflux ratio to 20-40:1 to extract leaf alcohol, preferably 25-35:1, more preferably 30:1.

[0029] In this invention, when fraction 2 is subjected to vacuum precision distillation in step (4), the distillation column adopts BX type metal wire mesh corrugated structured packing with a theoretical number of 100~150 plates, preferably 110~130 plates, and more preferably 120 plates. The distillation parameters are: system absolute pressure 1~3 kPa, preferably 1.5~2.5 kPa, and more preferably 2 kPa; column bottom temperature 90~120℃, preferably 100~110℃, and more preferably 105℃; column top condensation temperature 5~10℃, preferably 7~9℃, and more preferably 8℃; after total reflux stabilization for 3~5 h, preferably 3.3~4.5 h, and more preferably 4 h, each monomer component is collected stepwise according to the gradient reflux ratio, wherein the monomer components include linalool, methyl salicylate, α-ionone, and β-ionone.

[0030] In this invention, the gradient backflow stepwise sampling is as follows: Set the reflux ratio to 20-30:1 to extract linalool, preferably 23-27:1, more preferably 25:1; adjust the reflux ratio to 15-25:1 to extract methyl salicylate, preferably 18-22:1, more preferably 20:1; adjust the reflux ratio to 60-80:1 to extract α-ionone, preferably 65-75:1, more preferably 70:1; adjust the reflux ratio to 70-90:1 to extract β-ionone, preferably 75-85:1, more preferably 80:1.

[0031] In this invention, when the residual liquid in step (4) is subjected to vacuum precision distillation, the distillation column adopts θ-ring metal structured packing with a theoretical number of 60-80 plates, preferably 65-75 plates, and more preferably 70 plates. The distillation parameters are: system absolute pressure 0.5-1 kPa, preferably 0.7-0.9 kPa, and more preferably 0.8 kPa; column bottom temperature 120-150℃, preferably 130-140℃, and more preferably 135℃; column top condensation temperature 10-15℃, preferably 11-13℃, and more preferably 12℃; after total reflux stabilization for 2-3 hours, preferably 2.3-2.7 hours, and more preferably 2.5 hours, the monomer components are collected stepwise according to the gradient reflux ratio, wherein the monomer components include β-caryophyllene and salicylic acid leaf ester.

[0032] In this invention, the gradient backflow stepwise sampling is as follows: Set the reflux ratio to 10~20:1 to extract β-caryophyllene, preferably 13~17:1, more preferably 15:1; adjust the reflux ratio to 15~25:1 to extract salicylic acid leaf ester, preferably 18~22:1, more preferably 20:1.

[0033] In this invention, the process is carried out in a clean environment with light protection, an ambient temperature of 20-25°C, and a relative humidity of ≤40%. All processes involving heat-sensitive components are conducted with high-purity nitrogen gas throughout to isolate oxygen and prevent oxidation and degradation of the components.

[0034] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0035] Example

[0036] (1) Select fresh, mold-free, and impurity-free branches and leaves of Yunnan white pearl, wash them with deionized water, drain them, and then chop them into pieces with a particle size of 1-2 cm to obtain Yunnan white pearl fragments; put the Yunnan white pearl fragments into a distillation kettle, add distilled water at a mass ratio of 1:5, and carry out steam distillation under the following conditions: temperature 100℃, time 1.5h, pressure 0.03MPa; collect the distillation product and condense it to obtain condensate; let the condensate stand at 25℃ for 30min to separate the layers, and then separate the oil and water. The upper aqueous phase is Yunnan white pearl hydrosol, and the lower oil phase is Yunnan white pearl crude oil; carry out molecular distillation of Yunnan white pearl crude oil at a temperature of 80℃, a vacuum of 180Pa, a feed rate of 5mL / min, a scraper rotation speed of 160rpm, and a cooling temperature of 8℃ to obtain Yunnan white pearl essential oil; (2) Take 1L of Yunnan white pearl essential oil and dry it in a vacuum dryer at 40℃, 12kPa absolute pressure and 30rpm stirring speed. High-purity nitrogen is introduced throughout the process. The moisture content is sampled and tested every 30min using the Karl Fischer method. Drying is stopped when the moisture content is ≤0.05%. Under the same temperature and pressure conditions, vacuum degassing is continued for 45min to remove low-boiling-point volatile impurities and obtain pretreated essential oil.

[0037] (3) The pretreated essential oil is fed into a scraped-film molecular distillation apparatus for two-stage molecular distillation: First-stage molecular distillation: evaporation temperature 70℃, condensation surface temperature 2℃, system absolute pressure 0.3Pa, scraper rotation speed 200rpm, feed preheating temperature 65℃, feed rate 2mL / min. The light components at the top of the column are collected to obtain fraction 1 (19.2g), and the heavy components at the bottom of the column enter the second-stage molecular distillation; Second-stage molecular distillation: evaporation temperature 110℃, condensation surface temperature 12℃, system absolute pressure 0.2Pa, scraper rotation speed 250rpm, feed preheating temperature 100℃, feed rate 1.5mL / min. The light components at the top of the column are collected to obtain fraction 2 (930.5g), and the heavy components at the bottom of the column are the residue (28.3g).

[0038] (4) Precision distillation of fraction 1 under reduced pressure: Fraction 1 is fed into a CY-type metal wire mesh corrugated packing distillation column with 110 theoretical plates for stepwise extraction of high-purity single components. The basic process parameters are: system absolute pressure 8 kPa, column bottom temperature 82℃, column top condensing temperature 3℃, column body insulation temperature 84~85℃, and high-purity nitrogen is introduced throughout the process; after stabilizing under total reflux for 3 hours, fraction 1 is extracted stepwise according to gradient reflux. α-Pinene collection: The column top temperature is stable within the range of 42.5~43.0℃ (corresponding to 8kPa absolute pressure), the reflux ratio is 40:1, the collection rate is 0.1mL / min, and samples are taken for testing every 10min; when the α-pinene purity is ≥98% and the resolution between adjacent impurity peaks is ≥1.5, the qualified fraction is collected; when the column top temperature rises by more than 0.3℃ or the purity is <98%, collection is stopped, and the column is refluxed for 15min before proceeding to the next stage; the final qualified fraction is 3.62g, with a purity of 98.72%; β-Pinene collection: The column top temperature is stable within the range of 46.8~47.3℃ (corresponding to 8kPa absolute pressure), the reflux ratio is 50:1, the collection rate is 0.1mL / min, and samples are taken for testing every 10min; when the β-pinene purity is ≥98% and the resolution is ≥1.5, the qualified fraction is collected; when the column top temperature rises by more than 0.3℃ or the purity is <98%, collection is stopped, and the column is refluxed for 15min before proceeding to the next stage; the final qualified fraction is 4.28g, with a purity of 98.53%; 3-Carbaene extraction: The column top temperature is stable within the range of 53.5~54.0℃ (corresponding to 8kPa absolute pressure), the reflux ratio is 60:1, the extraction rate is 0.08mL / min, and samples are taken for testing every 15min; when the purity of 3-carbaene is ≥98% and the resolution is ≥1.5, the qualified fraction is collected; when the column top temperature rises by more than 0.3℃ or the purity is <98%, extraction is stopped, and the column is refluxed for 15min before proceeding to the next stage; the final qualified fraction is 2.61g, with a purity of 98.35%; trans-3-hexen-1-ol collection: The column top temperature is stable within the range of 58.2~58.7℃ (corresponding to 8kPa absolute pressure), the reflux ratio is 40:1, the collection rate is 0.05mL / min, and samples are taken for testing every 15min; when the purity of the target component is ≥98% and the resolution is ≥1.5, the qualified fraction is collected; when the column top temperature rises by more than 0.3℃ or the purity is <98%, collection is stopped, and the column is refluxed for 15min before proceeding to the next stage; the final qualified fraction is 0.82g, with a purity of 98.40%; Leaf alcohol collection: The column top temperature is stable within the range of 60.5~61.0℃ (corresponding to 8kPa absolute pressure), the reflux ratio is 30:1, the collection rate is 0.05mL / min, and samples are taken for testing every 15min; when the leaf alcohol purity is ≥98% and the resolution is ≥1.5, the qualified fraction is collected; when the column top temperature continues to rise without a stable range, collection is stopped; the final qualified fraction is 1.11g, with a purity of 98.42%.

[0039] Precision distillation of fraction 2 under reduced pressure: Fraction 2 was fed into a BX-type metal wire mesh corrugated packing distillation column with 130 theoretical trays. The system absolute pressure was 2 kPa, the bottom temperature was 105℃, the top condensing temperature was 8℃, and the column insulation temperature was 107~108℃. High-purity nitrogen was introduced throughout the process. After stabilizing under total reflux for 4 hours, fraction 2 was collected stepwise according to a gradient reflux ratio. Linalool collection: The column top temperature is stable within the range of 56.3~56.8℃ (corresponding to 2kPa absolute pressure), the reflux ratio is 25:1, the collection rate is 0.2mL / min, and samples are taken for testing every 15min; when the linalool purity is ≥98%, the resolution is ≥1.5, and there are no obvious degradation products, the qualified fraction is collected; when the column top temperature rises by more than 0.3℃ or the purity is <98%, collection is stopped, and the column is refluxed for 20min before proceeding to the next stage; the final qualified fraction is 3.01g, with a purity of 98.64%; Methyl salicylate collection: The column top temperature is stable within the range of 76.2~76.7℃ (corresponding to 2kPa absolute pressure), the reflux ratio is 20:1, the collection rate is 1.0mL / min, and samples are taken for testing every 30min; when the purity of methyl salicylate is ≥99% and the resolution is ≥1.5, the qualified fraction is collected; when the column top temperature rises by more than 0.3℃ or the purity is <99%, collection is stopped, and the column is refluxed for 20min before proceeding to the next stage; the final qualified fraction is 910.2g, with a purity of 99.52%; α-Ionone extraction: The column top temperature was maintained within a stable range of 90.5~91.0℃ (corresponding to 2kPa absolute pressure), with a reflux ratio of 70:1 and a extraction rate of 0.08mL / min. Samples were taken every 15min. When the target component purity was ≥98% and the resolution was ≥1.5, the qualified fraction was collected. When the column top temperature rose by more than 0.3℃ or the purity was <98%, extraction was stopped, and the column was refluxed for 20min before proceeding to the next stage. The final qualified fraction was 1.69g with a purity of 98.27%. β-Ionone extraction: The column top temperature is stable within the range of 93.1~93.6℃ (corresponding to 2kPa absolute pressure), the reflux ratio is 80:1, the extraction rate is 0.08mL / min, and samples are taken for testing every 15min; when the purity of the target component is ≥98%, the resolution is ≥1.5, and there are no obvious degradation products, the qualified fraction is collected; when the column top temperature continues to rise without a stable range, extraction is stopped; the final qualified fraction is 2.06g, with a purity of 98.31%.

[0040] Residual liquid was subjected to reduced pressure precision distillation: The residual liquid was fed into a 3×3mm stainless steel θ-ring packed distillation column with 70 theoretical trays. The system absolute pressure was 0.8 kPa, the reboiler temperature was 135℃, the top condensing temperature was 12℃, and the column body insulation temperature was 137~138℃. High-purity nitrogen was introduced throughout the process. After stabilizing under total reflux for 2.5 hours, the liquid was collected stepwise according to a gradient reflux ratio. β-Caryophyllene extraction: The column top temperature was maintained within a stable range of 108.2~108.7℃ (corresponding to 0.8kPa absolute pressure), with a reflux ratio of 15:1 and a extraction rate of 0.1mL / min. Samples were taken every 15min. When the target component purity was ≥98% and the resolution was ≥1.5, the qualified fraction was collected. When the column top temperature rose by more than 0.3℃ or the purity was <98%, extraction was stopped, and the column was refluxed for 15min before proceeding to the next stage. The final qualified fraction was 8.32g with a purity of 98.68%. Salicylic acid leaf alcohol ester extraction: The column top temperature is stable within the range of 121.5~122.0℃ (corresponding to 0.8kPa absolute pressure), the reflux ratio is 20:1, the extraction rate is 0.08mL / min, and samples are taken for testing every 15min; when the purity of the target component is ≥98%, the resolution is ≥1.5, and there are no obvious degradation products, the qualified fraction is collected; when the column top temperature continues to rise without a stable range, extraction is stopped; the final qualified fraction is 5.31g, with a purity of 98.24%.

[0041] The Yunnan white pearl essential oil obtained in step (1) of this embodiment was qualitatively tested and found to contain 11 compounds, as shown in Table 1.

[0042] Table 1. Main compounds in Yunnan white pearl essential oil

[0043] The 11 major compounds isolated using the method of this invention were analyzed by mass spectrometry, and their abundance differences with the mass spectra of corresponding standards were compared to quickly determine whether co-eluting impurities or matrix interference existed in the compounds isolated by this invention. The results are shown in [Figure number missing]. Figures 1-22 .

[0044] Depend on Figures 1-22 It is known that the method of the present invention can successfully separate 11 major compounds from Yunnan white pearl essential oil.

[0045] Comparative Example 1

[0046] Eleven major compounds in Yunnan white pearl oil were separated using the same method as in the previous example. The difference was that fraction 1 was passed through a Φ16mm stainless steel Pall ring packed distillation column with 110 theoretical plates for high-purity single-component fractional extraction. The results showed that α-pinene purity was 92.35%; β-pinene purity was 91.68%; and 3-carene purity was 86.37%. The purity of all products failed to meet the 98% requirement, and complete and effective separation of α-pinene and β-pinene was not achieved.

[0047] Comparative Example 2

[0048] Eleven major compounds in *Pterocarya stenoptera* essential oil were separated using the same method as in the previous example. The difference was that fraction 2 was passed through a BX-type metal wire mesh corrugated packing distillation column with 80 theoretical plates during vacuum distillation. The results showed that linalool had a purity of 97.21%, methyl salicylate 98.85%, α-ionone 90.12%, and β-ionone 91.36%. Only methyl salicylate had a purity exceeding 98%, while the purity of the other components was below 98%, and effective separation of ionone isomers was not achieved.

[0049] Comparative Example 3

[0050] Eleven major compounds in *Pterocarya stenoptera* essential oil were separated using the same method as in the previous example. The difference was that the reflux ratio was set to 30:1 when β-pinene was collected. The results showed that when the reflux ratio was set to 30:1, the purity of β-pinene was 93.12%, which did not meet the required purity standard. This also resulted in the purity of 3-carene being 94.07% when collected, which also failed to meet the required purity standard. The reason for this is likely that when the reflux ratio was 30:1 during β-pinene collection, β-pinene could not be effectively separated, causing it to mix into the subsequent 3-carene fraction. This prevented precise separation of β-pinene and 3-carene components, disrupting the entire separation system.

[0051] Comparative Example 4

[0052] Eleven major compounds in *Pterocarya stenoptera* essential oil were separated using the same method as in the previous example. The difference was that the reflux ratio was set to 100:1 when β-pinene was extracted. The results showed that when the reflux ratio was set to 80:1, the purity of β-pinene was 98.62%. Although β-pinene could be effectively separated from α-pinene and 3-carene, and the purity was improved by about 0.1% compared to the previous example, the β-pinene production cycle was extended from 80 minutes to 120 minutes, significantly increasing production costs and hindering enterprise promotion.

[0053] Comparative Example 5

[0054] (1) Select fresh, mold-free, and impurity-free branches and leaves of Yunnan white pearl, wash them with deionized water, drain them, and then chop them into pieces with a particle size of 1-2 cm to obtain Yunnan white pearl fragments; put the Yunnan white pearl fragments into a distillation kettle, add distilled water at a mass ratio of 1:5, and carry out steam distillation under the following conditions: temperature 100℃, time 1.5h, pressure 0.03MPa; collect the distillation product and condense it to obtain condensate; let the condensate stand at 25℃ for 30min to separate the layers, and then separate the oil and water. The upper aqueous phase is Yunnan white pearl hydrosol, and the lower oil phase is Yunnan white pearl crude oil; carry out molecular distillation of Yunnan white pearl crude oil at a temperature of 80℃, a vacuum of 180Pa, a feed rate of 5mL / min, a scraper rotation speed of 160rpm, and a cooling temperature of 8℃ to obtain Yunnan white pearl essential oil; (2) Take 1L of Yunnan white pearl essential oil and dry it in a vacuum dryer at 40℃, 12kPa absolute pressure and 30rpm stirring speed. High-purity nitrogen is introduced throughout the process. The moisture content is sampled and tested every 30min using the Karl Fischer method. Drying is stopped when the moisture content is ≤0.05%. Under the same temperature and pressure conditions, vacuum degassing is continued for 45min to remove low-boiling-point volatile impurities and obtain pretreated essential oil.

[0055] (3) The pretreated essential oil was fed into a BX-type metal wire mesh corrugated packing distillation column with 120 theoretical trays, and direct distillation was carried out using a fixed reflux ratio of 50:1. The results showed that this method could only obtain methyl salicylate with a purity of 98.23% and β-caryophyllene with a purity of 95.23%. The other nine compounds could not be effectively separated and were all mixed into the fore-fraction or residue.

[0056] In summary, this invention achieves, for the first time, the simultaneous separation of 11 high-purity active monomer components from *Pterocarya stenoptera* essential oil, covering almost all high-value-added components in the essential oil. This completely changes the resource-wasting status quo of existing technologies that only utilize methyl salicylate while other components are discharged with waste liquid. Furthermore, through the synergistic control of three core parameters—packing type, theoretical plate number, and reflux ratio—a synergistic separation system of "precise selection of packing type, gradient matching of theoretical plate number, and dynamic control of reflux ratio" has been established for the first time. This achieves the simultaneous high-purity separation of 11 active monomers from *Pterocarya stenoptera* essential oil, solving the core pain point of the difficulty in separating near-boiling-point isomers in existing technologies. As can be seen from the analysis of the embodiments and comparative examples in this application, changes in any parameter will affect the final separation effect.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for simultaneously separating multiple active ingredients from Yunnan white pearl essential oil, characterized in that, Includes the following steps: (1) Yunnan white pearl was subjected to steam distillation and molecular distillation in sequence to obtain Yunnan white pearl essential oil; (2) Dehydrate and degas the Yunnan white pearl essential oil to obtain pretreated essential oil; (3) The pretreated essential oil was subjected to two-stage molecular distillation to obtain fraction 1, fraction 2 and residual liquid; (4) By performing vacuum distillation on fraction 1, fraction 2 and the residue, multiple active ingredients can be separated from Yunnan white pearl essential oil simultaneously. The various active ingredients include: α-pinene, β-pinene, 3-carene, trans-3-hexen-1-ol, leaf alcohol, linalool, methyl salicylate, α-ionone, β-ionone, β-caryophyllene, and salicylic acid leaf alcohol ester.

2. The method according to claim 1, characterized in that, The conditions for steam distillation are: temperature 95~110℃, time 1~3h, and pressure 0.01~0.07MPa; wherein the mass ratio of Yunnan white pearl to distilled water during steam distillation is 1:3~6; the conditions for molecular distillation are: temperature 60~90℃, vacuum degree 100~300Pa, feed rate 2~7mL / min, scraper rotation speed 100~200rpm, and cooling temperature 5~10℃.

3. The method according to claim 1, characterized in that, The dehydration and degassing method is as follows: place Yunnan white pearl essential oil at 40~50℃ and absolute pressure of 8~12kPa to dehydrate until the water content is ≤0.05% to obtain dehydrated essential oil, and degas the dehydrated essential oil under the same conditions for 30~60min.

4. The method according to claim 1, characterized in that, In step (3), a scraped-film molecular distillation apparatus is used for two-stage molecular distillation; the specific method of the two-stage molecular distillation is as follows: First-stage molecular distillation: Evaporation temperature 60~80℃, condensation surface temperature 0~5℃, system absolute pressure 0.1~0.5Pa, scraper rotation speed 150~300rpm, feed rate 1~3mL / min, collect the light components at the top of the column to obtain fraction 1, and the heavy components at the bottom of the column enter the second-stage molecular distillation; Second-stage molecular distillation: Evaporation temperature 100~120℃, condensation surface temperature 10~15℃, system absolute pressure 0.1~0.3Pa, scraper rotation speed 200~350rpm, feed rate 0.8~2mL / min, collect the light components at the top of the column to obtain fraction 2, and the heavy components at the bottom of the column are the residue.

5. The method according to claim 1, characterized in that, In step (4), when fraction 1 is subjected to vacuum precision distillation, the distillation column uses CY-type metal wire mesh corrugated packing with a theoretical number of 80 to 120 plates. The distillation parameters are: system absolute pressure 5 to 10 kPa, column bottom temperature 70 to 95°C, column top condensation temperature 0 to 5°C. After total reflux stabilization for 2 to 4 hours, each monomer component is collected stepwise according to gradient reflux ratio.

6. The method according to claim 5, characterized in that, The gradient backflow stepwise extraction is as follows: Set the reflux ratio to 30-50:1 to extract α-pinene; adjust the reflux ratio to 40-60:1 to extract β-pinene; adjust the reflux ratio to 50-70:1 to extract 3-carene; adjust the reflux ratio to 30-50:1 to extract trans-3-hexen-1-ol; adjust the reflux ratio to 20-40:1 to extract leaf alcohol.

7. The method according to claim 1, characterized in that, In step (4), when fraction 2 is subjected to vacuum precision distillation, the distillation column uses BX type metal wire mesh corrugated packing with a theoretical number of 100-150 plates. The distillation parameters are: system absolute pressure 1-3 kPa, column bottom temperature 90-120℃, column top condensation temperature 5-10℃. After total reflux stabilization for 3-5 hours, each monomer component is collected step by step according to gradient reflux ratio.

8. The method according to claim 7, characterized in that, The gradient backflow stepwise extraction is as follows: Set the reflux ratio to 20-30:1 to extract linalool; adjust the reflux ratio to 15-25:1 to extract methyl salicylate; adjust the reflux ratio to 60-80:1 to extract α-ionone; adjust the reflux ratio to 70-90:1 to extract β-ionone.

9. The method according to claim 1, characterized in that, In step (4), when the residual liquid is subjected to vacuum precision distillation, the distillation column adopts θ-ring metal structured packing with a theoretical number of 60-80 plates. The distillation parameters are: system absolute pressure 0.5-1 kPa, column bottom temperature 120-150℃, column top condensation temperature 10-15℃. After the total reflux is stabilized for 2-3 hours, each monomer component is collected stepwise according to the gradient reflux ratio.

10. The method according to claim 9, characterized in that, The gradient backflow stepwise extraction is as follows: Set the reflux ratio to 10~20:1 to extract β-caryophyllene; adjust the reflux ratio to 15~25:1 to extract salicylic acid leaf ester.

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