Application of saponin compounds, preparation method thereof, sweetener, and sweet taste enhancer

Abstract

The application relates to an application of a saponin compound and a preparation method thereof, a sweetener and a sweet taste enhancer, and relates to the technical fields of food and medicine. The saponin compound is used as or prepared into a sweetener or a sweet taste enhancer. The saponin compound mainly provides a natural saponin compound which can be used as or prepared into a sweetener or a sweet taste enhancer, so as to meet the requirements of safety, high sweetness and low heat.

Description

Technical Field

[0001] This invention relates to the field of food and pharmaceutical technology, and in particular to the application and preparation method of a saponin compound, as well as sweeteners and sweetness enhancers. Background Technology

[0002] Taste refers to the unique sensation evoked on the mouth and tongue when consuming food and various compounds. Taste influences overall oral comfort and is a fundamental attribute for evaluating food. As one of the basic human senses, taste is crucial to an individual's overall well-being and quality of life.

[0003] Humans can perceive five basic tastes: sweet, umami, bitter, salty, and sour. Among these, sweetness holds a very important position. Humans (and animals) are inherently more inclined towards sweetness and avoid consuming typically bitter foods. Substances that produce sweetness are called sweeteners, including sugar sweeteners (such as sucrose, glucose, maltose, fructose, etc.) and non-sugar sweeteners. Based on their source, they are divided into synthetic sweeteners (such as saccharin, aspartame, acesulfame potassium, sucralose, etc.) and natural sweeteners.

[0004] Sucrose is the oldest and most widely used sugar sweetener in daily life. With rapid technological advancements and improved production levels, people have easier access to sucrose and other sugar sweeteners. However, excessive intake of sugar sweeteners has led to a growing number of people suffering from diseases such as diabetes, cardiovascular disease, obesity, high cholesterol, and tooth decay. Therefore, humanity has been continuously striving to find high-sweetness, low-calorie, non-nutritive sugar substitutes.

[0005] Synthetic sweeteners, such as acesulfame-K, aspartame, neotame, saccharin, sucralose, alitame, and cyclamate, are non-sugar high-intensity sweeteners that have become commonplace in daily life. They offer advantages such as high sweetness, small size, and low cost, and have captured a significant market share. However, these synthetic sweeteners also have many drawbacks, such as impure sweetness, varying degrees of bitterness, metallic aftertaste, or off-flavors, a significant difference from the taste of sucrose, and numerous safety concerns. Many countries, especially developed countries, have successively introduced management measures for chemically synthesized sweeteners. my country stipulates that the use of non-nutritive high-intensity sweeteners such as saccharin and cyclamate must not exceed the scope and dosage specified in GB2760 (Hygienic Standard for the Use of Food Additives), and the use of related chemically synthesized sweeteners is strictly prohibited in infant formula.

[0006] In summary, there is an urgent need for natural compounds with a sweet taste extracted from natural plants to be used as sweeteners or sweetness enhancers to meet the requirements of safety, high sweetness, and low calories. Summary of the Invention

[0007] In view of this, the present invention provides an application of saponin compounds and a method for their preparation, as well as sweeteners and sweetness enhancers. The main purpose is to provide natural saponin compounds that can be used as or used to prepare sweeteners or sweetness enhancers.

[0008] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0009] On one hand, embodiments of the present invention provide a saponin compound for use as or in the preparation of a sweetener or sweetness enhancer, wherein the saponin compound is any one of the following compounds:

[0010]

[0011]

[0012]

[0013]

[0014] Preferably, the saponin compound is isolated from Gynostemma pentaphyllum; preferably, the Gynostemma pentaphyllum is produced in Fujian Province; preferably, the isolated part is the aerial part of Gynostemma pentaphyllum.

[0015] Preferably, the preparation method includes the following steps:

[0016] Step 1): The Gynostemma pentaphyllum to be extracted is subjected to alcohol extraction to obtain an alcohol extract; then, the alcohol extract is subjected to extraction to obtain the target fraction;

[0017] Step 2): After dissolving the target fraction, perform column chromatography separation and gradient elution to obtain multiple fractions; two of these fractions are fraction 2 and fraction 3.

[0018] Step 3): After separating fraction 2, compounds 2, 5, 6, 4, and 7 are obtained; after separating fraction 3, compounds 8, 1, and 3 are obtained.

[0019] Preferably, in step 1), the Gynostemma pentaphyllum to be extracted is dried Gynostemma pentaphyllum powder.

[0020] Preferably, in step 1):

[0021] The *Gynostemma pentaphyllum* to be extracted was subjected to cold maceration extraction with ethanol to obtain an extract; the extract was then concentrated under reduced pressure to obtain an alcoholic extract; and / or

[0022] The alcohol extract was extracted with petroleum ether to obtain a petroleum ether extract and an aqueous phase fraction; wherein the aqueous phase fraction, after drying, is the target fraction.

[0023] Preferably, in step 2):

[0024] The target fraction was dissolved in water and then separated into segments using D101 macroporous resin column chromatography. Gradient elution was then performed using an ethanol-water solvent system. After solvent recovery, the fractions were combined based on TLC detection results to obtain fractions 1, 2, 3, 4, 5, 6, 7, and 8. Preferably, fraction 2 is the fraction collected after elution using an ethanol-water solvent system with an ethanol volume fraction of 30-50%; and fraction 3 is the fraction collected after elution using an ethanol-water solvent system with an ethanol volume fraction of 50-70%.

[0025] Preferably, in step 3):

[0026] After dissolving fraction 2, column chromatography separation is performed, followed by gradient elution using a methanol-water solvent system. The solvent is recovered, and the fractions are combined according to the TCL detection results to obtain multiple fractions; one of the fractions is fraction 2E; preferably, fraction 2E is the fraction collected after elution using a methanol-water solvent system with a methanol volume fraction of 60-80%.

[0027] The fraction 2E was subjected to gradient elution using a dichloromethane-methanol system. The fractions were then combined based on the TCL detection results to obtain multiple fractions; two of these fractions were fraction 2E8 and fraction 2E6. Preferably, the elution ratio for fraction 2E8 was a dichloromethane to methanol volume ratio of 6:2 to 6:5; and the elution ratio for fraction 2E6 was a dichloromethane to methanol volume ratio of 4:1 to 3:1.

[0028] After dissolving fraction 2E8, it was fractionated using a medium-pressure liquid chromatography system and eluted using a methanol-water system. The fractions were combined according to the TCL detection results to obtain multiple fractions; one of the fractions was fraction 2E8B. After purifying fraction 2E8B, compound 2 was obtained. Preferably, fraction 2E8B was collected after elution using a methanol-water system with a methanol volume fraction of 50-60%.

[0029] After dissolving fraction 2E6, it was fractionated using a medium-pressure liquid chromatography system and eluted using a methanol-water system. Based on TLC results, the fractions were combined to obtain multiple fractions; two of these fractions were fraction 2E6E and fraction 2E6G. Fraction 2E6E was separated to obtain compounds 5 and 6; fraction 2E6G was separated to obtain compounds 4 and 7. Preferably, fraction 2E6E was collected after elution using a methanol-water system with a methanol volume fraction of 50-60%; preferably, fraction 2E6G was collected after elution using a methanol-water system with a methanol volume fraction of 60-65%.

[0030] Preferably, in step 3):

[0031] The fraction 3 is subjected to gradient elution using a dichloromethane-methanol system. The fractions are combined according to the TCL detection results to obtain multiple fractions. Among them, one fraction is fraction 3G. Preferably, the elution ratio corresponding to fraction 3G is: the volume ratio of dichloromethane to methanol is 4:1~3~1.

[0032] After dissolving fraction 3G, it is fractionated using a medium-pressure liquid chromatography system and subjected to gradient elution using a methanol-water system. Based on the TCL detection results, the fractions are combined to obtain multiple fractions. Three of these fractions are: fraction 3G1 and fraction 3G3. Preferably, fraction 3G1 is the fraction collected after elution using a methanol-water system with a methanol volume fraction of 50-55%. Preferably, fraction 3G3 is the fraction collected after elution using a methanol-water system with a methanol volume fraction of 60-65%.

[0033] Specifically, after purifying and separating fraction 3G1, compound 8 is obtained; after purifying and separating fraction 3G3, compounds 1 and 3 are obtained.

[0034] In another aspect, embodiments of the present invention provide a sweetener, wherein the sweetener includes the above-mentioned saponin compounds.

[0035] In another aspect, the present invention provides a sweetness enhancer, characterized in that the sweetness enhancer comprises the above-mentioned saponin compounds.

[0036] Compared with the prior art, the application of saponin compounds and their preparation methods, sweeteners, and sweetness enhancers of the present invention have at least the following beneficial effects:

[0037] On the one hand, this invention discovers for the first time eight new natural saponin compounds that can be used as sweeteners or sweetness enhancers (among which, compounds 1 and 4 are new natural compounds, which are new compounds extracted for the first time in this application). These eight natural saponin compounds have a sweet taste, or a sweet taste with a slightly astringent or licorice-like flavor. Although some compounds have certain astringent or licorice-like off-flavors, they have a high sweetness, with a sweetness level of 20-166 times that of sucrose. They can be used as sweeteners / sweetness enhancers in the food and pharmaceutical fields.

[0038] On the other hand, this invention is the first to extract eight new natural saponin compounds from Gynostemma pentaphyllum produced in Fujian, which can be used as sweeteners or sweetness enhancers. Existing related technologies have not reported that "these eight natural saponin compounds can be used as sweeteners or sweetness enhancers".

[0039] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Detailed Implementation

[0040] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description, in conjunction with preferred embodiments, provides a detailed explanation of the specific implementation methods, structures, features, and effects according to the present invention. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0041] Gynostemma pentaphyllum (Thunb.) Makino is a herbaceous climbing plant belonging to the genus Gynostemma in the family Cucurbitaceae. It is also known as Seven Galls Grass and Grows Everywhere. Studies have shown that the main components of Gynostemma pentaphyllum are 2α-hydroxyginsenosides and ginsenoside triterpenoid saponins. Currently, more than 300 saponin compounds have been isolated and reported from Gynostemma pentaphyllum. In 1983, Japanese scholar Takemoto isolated and identified a dammarane-type triterpenoid saponin compound, gypenoside XX, from Gynostemma pentaphyllum extract. Subsequent studies confirmed its sweetness, but its sweetness level was not clearly defined (AD Kinghorn; N.-C. Kim; DSHL Kim, Terpenoid Glycoside Sweeteners. In Naturally Occurring Glycosides: Chemistry, Distribution and Biological Properties; R. Ikan, Ed.; John Wiley & Sons: Chichester, UK, 1999; pp 399–429.). Subsequent studies reported that 12 dammarane-type triterpenoid saponins from Gynostemma pentaphyllum could be used as sweeteners or sweetness enhancers, but no definitive data on sweetness level or sweetness threshold were available. In preliminary research, the inventors compared the sweetness of Gynostemma pentaphyllum from different origins and found that the sweetness of Gynostemma pentaphyllum from Yunnan was significantly superior to that from other origins. Through systematic research, 15 new natural products were discovered, all exhibiting varying degrees of sweetness, ranging from 10 to 100 times that of sucrose. In further research, the inventors discovered a type of Gynostemma pentaphyllum from Fujian Province with a sweet-bitter taste. Although mixed with bitterness, it possessed a high level of sweetness, exceeding that of the sweet Gynostemma pentaphyllum from Yunnan. Through systematic research, eight sweet Gynostemma pentaphyllum saponins were discovered, with a sweetness level ranging from 20 to 166 times that of sucrose, far exceeding the sweetness of the Yunnan sweet Gynostemma pentaphyllum saponins. Compounds 1 and 4 are new natural products.

[0042] Example 1

[0043] This embodiment is mainly used to extract natural sweet compounds from Gynostemma pentaphyllum produced in Fujian Province.

[0044] 1. Instruments and Materials

[0045] Specific rotation: Autopol VI, Serial#91058; Infrared spectrum: Thermo NICOLET iS10; Ultraviolet spectrum: UV-2700 series; ESI and HRESI: Shimadzu UPLC-IT-TOF liquid chromatography-ion trap time-of-flight chromatography-mass spectrometry; NMR data: Bruker AVANCEⅢ 500MH and AV-600, TMS as internal standard, chemical shift δ in ppm, coupling constant J in Hz.

[0046] Rotary evaporator (EYELA, Japan and Büchi, Switzerland); medium-pressure liquid chromatograph (Büchi, Switzerland); semi-preparative high-performance liquid chromatograph (Jiangsu Hanbang Technology Co., Ltd.); chromatographic columns (YMC-Pack ODS-AQ, 10mm×250mm; YMC-Pack CN, 10mm×250mm).

[0047] Normal-phase silica gel (80-100 mesh, 200-300 mesh, Qingdao Ocean Chemical Plant); Normal-phase silica gel plate (Qingdao Ocean Chemical Plant); Reverse-phase silica gel (YMC Company); Reverse-phase silica gel plate (Merck Company, Germany); Sephadex LH-20 gel (GE Healthcare, Sweden); Macroporous adsorption resin D101 (Tianjin Xingnan Yunan Polymer Technology Co., Ltd.); Macroporous adsorption resin HP-20 (Tianjin Xingnan Yunan Polymer Technology Co., Ltd.); Colorimetric reagent: sulfuric acid-vanillin solution.

[0048] The Gynostemma pentaphyllum plant material required for this experiment was collected in Zhangzhou City, Fujian Province in 2021.

[0049] 2. The preparation steps of natural sweet compounds are as follows:

[0050] Four kilograms of dried and pulverized aerial parts of Gynostemma pentaphyllum were extracted three times with 95% ethanol (v / v) for 48 hours each time. The combined extracts were concentrated under reduced pressure using a rotary evaporator to recover the ethanol, yielding an ethanol extract. Two L of distilled water was added to the ethanol extract for suspension, followed by six extractions with an equal volume of petroleum ether, yielding a petroleum ether extract (24.61 g, denoted as GPPP) and an aqueous fraction (450 g, denoted as GPMP).

[0051] GPMP (450 g) was dissolved in water and separated into fractions using D101 macroporous resin column chromatography with gradient elution using an ethanol-water solvent system (0%, 30%, 50%, 70%, 90% M / W). The solvent was recovered using a rotary evaporator, and the fractions were combined by TLC analysis to obtain eight fractions: fraction 1 (Fr. 1, 21 g), fraction 2 (Fr. 2, 81 g), fraction 3 (Fr. 3, 122 g), fraction 4 (Fr. 4, 10 g), fraction 5 (Fr. 5, 9 g), fraction 6 (Fr. 6, 6 g), fraction 7 (Fr. 7, 2 g), and fraction 8 (Fr. 8, 3 g). It should be noted that after elution using each elution ratio, TCL analysis is required. Depending on the composition, the fractions may be divided into multiple fractions. Finally, the fractions with the same or similar fractions obtained after elution and analysis of all elution ratios are combined to obtain the above 8 fractions.

[0052] Fraction 2 (81 g) was dissolved in water and separated by Diaion HP-20 column chromatography using a gradient elution system of methanol-water solvent (0%, 30%, 50%, 70%, 90% M / W). The solvent was recovered by rotary evaporation, and the fractions were combined after TLC analysis to obtain eight fractions: fraction 2A (2 g), fraction 2B (11 g), fraction 2C (6 g), fraction 2D (1.6 g), fraction 2E (20.6 g), fraction 2F (9.5 g), fraction 2G (8 g), and fraction 2H (6 g).

[0053] Fraction 2E (20 g) was mixed with 80-100 mesh silica gel, packed into a 200-300 mesh silica gel column, and eluted with a gradient of dichloromethane:methanol (8:2, 7:3, 6:4). TLC analysis and pooling yielded 12 fractions: Fraction 2E1 (800 mg), Fraction 2E2 (560 mg), Fraction 2E3 (735 mg), Fraction 2E4 (340 mg), Fraction 2E5 (690 mg), Fraction 2E6 (2 g), Fraction 2E7 (3 g), Fraction 2E8 (5 g), Fraction 2E9 (986 mg), Fraction 2E10 (500 mg), Fraction 2E11 (2 g), and Fraction 2E12 (350 mg).

[0054] Fraction 2E8 (5 g) was dissolved in methanol and fractionated using a medium-pressure liquid chromatography system with a methanol-water gradient elution (50%, 60%, 70%, 100%). The fractions were then combined to obtain eight fractions: fraction 2E8A (800 mg), fraction 2E8B (2 g), fraction 2E8C (800 mg), fraction 2E8D (21 mg), fraction 2E8E (46 mg), fraction 2E8F (86 mg), fraction 2E8G (514 mg), and fraction 2E8H (86 mg). Fraction 2E8B (2 g) was dissolved in methanol and separated into compound 2 (178 mg) using semi-preparative high-performance liquid chromatography (YMC-Pack ODS-AQ, 58% methanol-water). Of these, fraction 2E8G (514 mg) was dissolved in methanol and separated into compound 9 (256 mg) by semi-preparative high performance liquid chromatography (YMC-Pack C18, 78% methanol-water).

[0055] Fraction 2E6 (2 g) was dissolved in methanol and fractionated using a medium-pressure liquid chromatography system with a methanol-water gradient elution (50%, 60%, 100%). The fractions were then combined to obtain eight fractions: fraction 2E6A (32 mg), fraction 2E6B (85 mg), fraction 2E6C (800 mg), fraction 2E6D (18 mg), fraction 2E6E (890 mg), fraction 2E6F (500 mg), fraction 2E6G (96 mg), and fraction 2E6H (150 mg). Fraction 2E6E (89 mg) was dissolved in methanol and separated into compounds 5 (38 mg) and 6 (45 mg) using semi-preparative high-performance liquid chromatography (YMC-PackODS-AQ, 63% methanol-water). Of these, fraction 2E6G (96 mg) was dissolved in methanol and separated into compounds 4 (46 mg) and 7 (22 mg) by semi-preparative high performance liquid chromatography (YMC-Pack C18, 68% methanol-water).

[0056] Fraction 3 (122 g) was mixed with 80-100 mesh silica gel, packed into a 200-300 mesh silica gel column, and eluted with a gradient of dichloromethane:methanol (15:1, 9:1, 8:2, 7:3, methanol). TLC analysis and pooling yielded eight fractions: fraction 3A (2 g), fraction 3B (1 g), fraction 3C (2.9 g), fraction 3D (5.2 g), fraction 3E (7.2 g), fraction 3F (36.4 g), fraction 3G (12.3 g), and fraction 3H (37.9 g).

[0057] Fraction 3G (12g) was dissolved in methanol and fractionated using a medium-pressure liquid chromatography system with a methanol-water gradient elution (50%, 60%, 65%, 70%, 100%). The fractions were then combined to obtain 11 fractions: fraction 3G1 (940mg), fraction 3G2 (673mg), fraction 3G3 (711mg), fraction 3G4 (830mg), fraction 3G5 (193mg), fraction 3G6 (2.9g), fraction 3G7 (870mg), fraction 3G8 (600mg), fraction 3G9 (2.37g), fraction 3G10 (580mg), and fraction 3G11 (820mg).

[0058] Fraction 3G1 (331 mg), dissolved in methanol, was separated to compound 8 (40 mg) using semi-preparative high-performance liquid chromatography (YMC-Pack ODS-AQ, 63% methanol-water). Fraction 3G2 (673 mg), dissolved in methanol, was separated to compound 12 (48 mg) using semi-preparative high-performance liquid chromatography (YMC-Pack ODS-AQ, 70% methanol-water).

[0059] Fraction 3G3 (711 mg) was dissolved in methanol and separated into compound 1 (107 mg) and compound 3 (144 mg) by semi-preparative high performance liquid chromatography (YMC-Pack SB-C18, 58% methanol-water).

[0060] Fraction 3G7 (870 mg) was mixed with 80-100 mesh silica gel, packed into a 200-300 mesh silica gel column, and eluted with a gradient of dichloromethane:methanol (8:2, 7:3, methanol). TLC detection and pooling yielded seven fractions: fraction 3G7A (62 mg), fraction 3G7B (129 mg), fraction 3G7C (41 mg), fraction 3G7D (45 mg), fraction 3G7E (31 mg), fraction 3G7F (38 mg), and fraction 3G7G (303 mg). Fraction 3G7B (129 mg) was dissolved in methanol and separated from compound 11 (80 mg) using semi-preparative high-performance liquid chromatography (YMC-Pack ODS-AQ, 70% methanol-water).

[0061] Fraction 3G9 (2.37 g) was mixed with 80–100 mesh silica gel, packed into a 200–300 mesh silica gel column, and eluted with a dichloromethane:methanol gradient (8:2, 7:3, methanol). TLC analysis and pooling yielded two fractions: fraction 3G9A (1.5 g) and fraction 3G9B (700 mg), where 3G9A was compound 10.

[0062] The structural formulas of compounds 1-12 are as follows:

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] The NMR data for the aforementioned new natural compounds 1 and 4 are as follows:

[0069] Compound 1, white powder. ;UV(MeOH)λmax(nm)(logε): 203.00(3.07); IR(KBr): 3432, 2943, 2879, 1640, 1453, 1421, 1385, 1261, 1165, 1078, 1039, 895, 845, 630, 577, 425cm -1 ESI-MS m / z 1133 [M+Na] + ;HRESIMS m / z 1109.5742(calcd forC 53 H 90 O 24 ,1108.5749).

[0070] Compound 4, white powder. ;UV(MeOH)λmax(nm)(logε): 203.00(2.94); IR(KBr): 3433, 2927, 2877, 1639, 1455, 1419, 1343, 1265, 1162, 1077, 1042, 895, 659, 615cm -1 ESI-MS m / z 1256 [MH] - ;HRESIMS m / z 947.5222(calcd for C 47 H 80 O 19 ,947.5221).

[0071] Table 1 shows the NMR data for compounds 1 and 4:

[0072]

[0073]

[0074]

[0075] Example 2

[0076] This embodiment focuses on the taste and sensory evaluation of monomeric compounds 1-12 isolated from Gynostemma pentaphyllum in Example 1.

[0077] Preparation of compound solutions: Accurately weigh a certain amount of the compound, dissolve it in water, and then dilute it to prepare a stock solution with a concentration of 1 mg / mL. Dilute it again to prepare a series of sample solutions with concentration gradients, namely 1 mg / mL, 0.5 mg / mL, 0.25 mg / mL, 0.2 mg / mL, 0.125 mg / mL, 0.1 mg / mL, 0.04 mg / mL, etc.

[0078] Preparation of sucrose solutions: Accurately weigh a certain amount of sucrose and prepare solutions with water at concentrations of 10 mg / mL and 20 mg / mL, which are used as a control with the sample to determine the relative sweetness of the compound and sucrose.

[0079] Sensory panel members tasted the compound and the sucrose solution to determine the concentration C of the compound with a sweetness equivalent to sucrose. 化合物 C 化合物 With C 蔗糖 The multiple between the two is the relative sweetness of the compound.

[0080] The sensory panel members tasted each sample until they found a solution that no longer tasted sweet. The concentration of the sample solution was C. n With the second to last sample concentration C n-1 The arithmetic mean of the compounds is the sweetness threshold.

[0081] Table 2 shows the taste sensory evaluation results of the compounds.

[0082]

[0083]

[0084] Note: *Sweetness: The ratio of sweetness of sucrose samples to sucrose concentration is the relative sweetness of sucrose.

[0085] As can be seen from Table 2:

[0086] (1) The main flavor of compounds 1-8 of the present invention is sweet. Although some are mixed with bitterness, they have a high sweet taste. Their sweetness is 20-166 times that of sucrose and can be used as sweeteners / sweetness enhancers in the food and pharmaceutical fields.

[0087] (2) Although compounds 9-12 are also extracted from Gynostemma pentaphyllum and their structures are very similar to those of compounds 1-8 of this invention, the main difference lies in the different individual groups; this shows that changes in the groups in the compound structure have a significant impact on the sweetness of the compound, and can even change the taste from sweet to bitter.

[0088] In fact, this invention involves extensive research on Gynostemma pentaphyllum. In previous works, the inventors extracted various sweet and bitter compounds from Gynostemma pentaphyllum from Yunnan. The inventors discovered that the sweet compounds share few commonalities, as changes in the individual groups or their quantities can easily transform them into bitter compounds. Therefore, it is impossible to provide a skeletal overview of the sweet compounds extracted from Gynostemma pentaphyllum, nor is it possible to directly determine whether a compound is sweet based on its structure.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. The use of a saponin compound as or in the preparation of a sweetener or sweetness enhancer, wherein, The saponin compound is any one of the following compounds: ； Compound 1; ； Compound 4; ； Compound 7.

2. The use of the saponin compound according to claim 1 as or in the preparation of a sweetener or sweetness enhancer, characterized in that, The saponin compounds were isolated from Gynostemma pentaphyllum.

3. The use of the saponin compound according to claim 2 in the preparation of sweeteners or sweetness enhancers, characterized in that, The Gynostemma pentaphyllum mentioned is produced in Fujian Province.

4. The use of the saponin compound according to claim 2 in the preparation of sweeteners or sweetness enhancers, characterized in that, The separated part is the above-ground part of Gynostemma pentaphyllum.

5. The use of the saponin compound according to any one of claims 2-4 in the preparation of a sweetener or sweetness enhancer, characterized in that, The preparation method of the saponin compound includes the following steps: Step 1): The Gynostemma pentaphyllum to be extracted is subjected to ethanol extraction to obtain an ethanol extract; then, the ethanol extract is subjected to extraction to obtain the target fraction; wherein, the Gynostemma pentaphyllum to be extracted is subjected to cold soaking extraction with ethanol to obtain an extract; the extract is concentrated under reduced pressure to obtain an ethanol extract; the ethanol extract is subjected to extraction with petroleum ether to obtain a petroleum ether extract and an aqueous phase fraction; wherein, the aqueous phase fraction is the target fraction after drying; Step 2): After dissolving the target fraction, perform column chromatography separation and gradient elution to obtain multiple fractions; two of these fractions are fraction 2 and fraction 3. The target fraction was dissolved in water, separated and fragmented using D101 macroporous resin column chromatography, and then eluted using an ethanol-water solvent system. After solvent recovery, the fractions were combined according to TLC detection results to obtain fractions 1, 2, 3, 4, 5, 6, 7, and 8. Fraction 2 was collected after elution using an ethanol-water solvent system with an ethanol volume fraction of 30-50%, and fraction 3 was collected after elution using an ethanol-water solvent system with an ethanol volume fraction of 50-70%. Step 3): After separating fraction 2, compounds 4 and 7 are obtained; after separating fraction 3, compound 1 is obtained. In this process, after dissolving fraction 2, column chromatography separation is performed, followed by gradient elution using a methanol-water solvent system. The solvent is recovered, and the fractions are combined based on the TCL detection results to obtain multiple fractions. One of these fractions is fraction 2E. Fraction 2E is the fraction collected after elution using a methanol-water solvent system with a methanol volume fraction of 60-80%. The fraction 2E was subjected to gradient elution using a dichloromethane-methanol system. The fractions were combined based on the TCL detection results to obtain multiple fractions, including fraction 2E6. The elution ratio corresponding to fraction 2E6 was a volume ratio of dichloromethane to methanol of 4:1 to 3:

1. After dissolving fraction 2E6, it was fractionated using a medium-pressure liquid chromatography system and eluted using a methanol-water system. The fractions were then combined based on TLC results to obtain multiple fractions, including fraction 2E6G. Fraction 2E6G was further separated to obtain compounds 4 and 7. Fraction 2E6G was collected after elution using a methanol-water system with a methanol volume fraction of 60-65%. The fraction 3 is subjected to gradient elution using a dichloromethane-methanol system. The fractions are combined according to the TCL detection results to obtain multiple fractions. One of the fractions is fraction 3G. The elution ratio corresponding to fraction 3G is a volume ratio of dichloromethane to methanol of 4:1 to 3:

1. After dissolving fraction 3G, it is fractionated using a medium-pressure liquid phase system and eluted with a methanol-water system. The fractions are then combined based on the TCL detection results to obtain multiple fractions, including fraction 3G3. Fraction 3G3 is the fraction collected after elution with a methanol-water system containing 60-65% methanol by volume. Compound 1 was obtained by purifying and separating fraction 3G3.

6. The use of the saponin compound according to claim 5 in the preparation of a sweetener or sweetness enhancer, characterized in that, In step 1): the Gynostemma pentaphyllum to be extracted is dried Gynostemma pentaphyllum powder.

7. A sweetener, characterized in that, The sweetener includes saponins; wherein the saponins are any one of the following compounds: ； Compound 1; ； Compound 4.

8. A sweetness enhancer, characterized in that, The sweetness enhancer includes saponin compounds; wherein the saponin compounds are any one of the following compounds: ； Compound 1; ； Compound 4.

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