1. A tannin compound is characterized in that the name of the tannin compound is 4- [ beta-D- (2-syringyl) glucosyloxy ] -3-methoxybenzoic acid, and the tannin compound has a structure shown in a formula (1):

2. the tannin compound of claim 1, wherein the tannin compound is a white amorphous powder, is readily soluble in methanol and acetone, and is insoluble in chloroform.

3. A method of extracting tannins according to claim 1 or 2, comprising the steps of:

s1, leaching the whole acanthus ilicifolius plant dry powder at room temperature by using an ethanol water solution, filtering an extracting solution, concentrating to obtain an extract, dissolving and dispersing the extract by using a methanol water solution to obtain an extract dispersion liquid, extracting the extract dispersion liquid by using petroleum ether, and concentrating the obtained methanol phase after suction filtration to obtain a methanol phase thick paste;

s2, separating and purifying the methanol-phase thick paste by adopting a macroporous resin chromatographic column and using 30 +/-5% ethanol water solution as an eluent, and concentrating under reduced pressure to obtain a component A;

s3, separating and purifying the component A by adopting an RP-18 reverse phase column and using a 15 +/-5% acetone aqueous solution as an eluent, and concentrating under reduced pressure to obtain a component A3;

s4, separating and purifying the component A3 by using a gel column and methanol as an eluent, and concentrating under reduced pressure to obtain a component A3.1;

s5, separating and purifying the component A3.1 by using an RP-18 reverse phase column and using a 35 +/-5% methanol aqueous solution as an eluent, and concentrating under reduced pressure to obtain a component A3.1.2;

s6, separating and purifying the component A3.1.2 by using a gel column and using an alcohol-ketone mixed solution composed of acetone and methanol according to a volume ratio of (2-4): 1 as an eluent, concentrating under reduced pressure, then separating and purifying by using a normal phase silica gel column and using an alcohol-hydrocarbon mixed solution composed of chloroform and methanol according to a volume ratio of (20-25): 1 as an eluent, and concentrating under reduced pressure to obtain the tannin compound.

4. The method for extracting tannin compounds according to claim 3, wherein in step S1, the dosage ratio of the total Acanthus ilicifolius dry powder to the ethanol aqueous solution is 1g (4-8) mL; the concentration of the ethanol water solution is 95 +/-2%; the leaching time is 20-30 h, and the leaching times are 1-3; the concentration of the methanol water solution is 80 +/-5%; the dosage ratio of the extract to the methanol water solution is (300-400) g: 1L; the extraction times are 2-4 times, and the ratio of the amount of petroleum ether used in each extraction to the amount of methanol aqueous solution used in dispersion is (600-800) mL: 1L.

5. The method for extracting a tannin compound according to claim 3, wherein in step S2, the macroporous resin chromatographic column is an HP-20 macroporous resin chromatographic column; the methanol-phase thick paste is subjected to ultrasonic dissolution and dispersion by pure water and then is subjected to sample loading, wherein the sample loading flow speed is 2-6 BV/h; eluting with water to remove impurities before eluting with ethanol water solution.

6. The method for extracting tannins according to claim 3, wherein in step S3, the RP-18 reverse phase column has an inner diameter of 30 to 40mm and a length of 200 to 250 mm.

7. The method for extracting tannin compounds of claim 3, wherein in the step S4, the gel column is a Sephadex LH-20 gel column.

8. The method for extracting tannins according to claim 3, wherein in step S5, the RP-18 reverse phase column has an inner diameter of 20 to 30mm and a length of 200 to 250 mm.

9. The method for extracting tannin compounds of claim 3, wherein in the step S6, the gel column is a Sephadex LH-20 gel column.

10. Use of a tannin compound of claim 1 or 2 in anti-inflammatory, hemostatic, antidiarrheal, antibacterial, antiviral, anti-lipid peroxidation, free radical scavenging, anti-mutagenic or anti-tumor applications.

Background

Mangrove is a woody plant community distributed in the coastal intertidal zone of tropical and subtropical regions, mainly comprising evergreen trees and shrubs, and is a special ecosystem for the transition from land to ocean. Mangrove resources in China are rich and are mainly distributed in coastal areas of provinces such as Fujian, Guangxi, Guangdong, Hainan and Taiwan. There are 28 species (including variety) of 15 genus of the 12 family of the rhododendron plant and 14 species of 13 genus of the 11 family of the hemimangrove plant, among which 23 species having medicinal value are present, and there are mainly 13 species of the rhododendron plant as folk medicinal species, including the positive rhododendron Rhizophora apiculata, the red sea olive Rhizophora phylosa, the bruuiera gymnorrhiza, the lotus Bruguiera sexaria, the autumn Kandelia candel, the ceraops ceriopsis tagal, the sea lacquer extracoacia aggregatocha, the mouse Acacia ilicifolia, the small flower mouse Acacia ebas ebrataria, the silver leaf tree Heritiera toralis, the sea mango Cerbera manghas, the Hibiscus histica and the sea mulberry Sonella. Because the mangrove forest is located in the interface area between land and sea and in the intertidal zone environment where the mangrove forest is periodically submerged in sea water, the mangrove plant forms unique structure and functional adaptability, such as prop root, respiratory root, fetal bud, salt secretion mechanism and the like. Compared with terrestrial plants, the secondary metabolites of mangrove plants have novel chemical structures, show unique biological activity and provide abundant resources for the development of marine plant drugs.

Acanthus ilicifolius Linn is a non-embryogenic mangrove plant, belongs to Acanthaceae Acanthus ilicifolius, and generally grows in intertidal mud beaches with high salinity and alkalinity in tropical zone or subtropical zone, saline soil below estuary high tide line or bay with thick silt. The heat-transfer material is distributed in tropical and subtropical coastal areas such as Fujian, Guangxi, Guangdong and Hainan areas in China. In morphology, the acanthus ilicifolius is a vertical shrub with the height of two meters, the stem is thick and strong, the leaves are in a thorn shape, the leaves are in a shape from a long circle to a long circle and are in a needle shape, the tip of each leaf is sharp, the base of each leaf is wedge-shaped, the edge of each leaf is in a feather shape and is shallow-split, and a sharp and hard thorn is protruded from the top end of each split piece. Spike-like inflorescence is terminal, corolla is white, capsule is oval, four seeds are contained, and the seeds are flat and light yellow. The research of the raw pharmacy finds that the root of the acanthus ilicifolius has developed ventilating cells and the middle vessel of the leaves has four vascular bundles with obvious characteristics. The ilicifolius seu acanthus has a long folk medicinal history as an important medicinal mangrove plant, and the efficacy of relieving cough and asthma, clearing heat and detoxicating, and reducing swelling and dissipating stagnation is recorded in the national Chinese herbal compilation of 1978. The acanthus ilicifolius is used in the folk Hainan area of China to relieve swelling, detoxify, relieve pain, treat lymph node enlargement, acute liver and spleen diseases, jaundice and the like. Pounding Acanthus ilicifolius root, decocting in water, and orally administering with Mel to obtain the final product for treating hepatitis B. Acanthus ilicifolius is used in Guangxi to cure lumbar muscle strain, neuralgia and phlegm, while Fujian folk is used to cure male infertility. In some southeast Asia countries, such as India and Thailand, Leba Acanthopanax trifoliatus branches and leaves are traditionally used for treating neuralgia, rheumatism, snake bite, paralysis and the like. Therefore, the mangrove acanthus ilicifolius has wide folk medicine base.

Disclosure of Invention

The invention aims to provide a novel tannin compound extracted from mangrove acanthus ilicifolius, an extraction method and application thereof.

Specifically, the invention provides a tannin compound, wherein the name of the tannin compound is 4- [ beta-D- (2-syringyl) glucosyloxy ] -3-methoxybenzoic acid, and the tannin compound has a structure shown in a formula (1):

the tannin compound is white amorphous powder, is easily soluble in methanol and acetone, and is insoluble in chloroform.

The invention also provides an extraction method of the tannin compounds, which comprises the following steps:

s1, leaching the whole acanthus ilicifolius plant dry powder at room temperature by using an ethanol water solution, filtering an extracting solution, concentrating to obtain an extract, dissolving and dispersing the extract by using a methanol water solution to obtain an extract dispersion liquid, extracting the extract dispersion liquid by using petroleum ether, and concentrating the obtained methanol phase after suction filtration to obtain a methanol phase thick paste;

s2, separating and purifying the methanol-phase thick paste by adopting a macroporous resin chromatographic column and using 30 +/-5% ethanol water solution as an eluent, and concentrating under reduced pressure to obtain a component A;

s3, separating and purifying the component A by adopting an RP-18 reverse phase column and using a 15 +/-5% acetone aqueous solution as an eluent, and concentrating under reduced pressure to obtain a component A3;

s4, separating and purifying the component A3 by using a gel column and methanol as an eluent, and concentrating under reduced pressure to obtain a component A3.1;

s5, separating and purifying the component A3.1 by using an RP-18 reverse phase column and using a 35 +/-5% methanol aqueous solution as an eluent, and concentrating under reduced pressure to obtain a component A3.1.2;

s6, separating and purifying the component A3.1.2 by using a gel column and using an alcohol-ketone mixed solution composed of acetone and methanol according to a volume ratio of (2-4): 1 as an eluent, concentrating under reduced pressure, then separating and purifying by using a normal phase silica gel column and using an alcohol-hydrocarbon mixed solution composed of chloroform and methanol according to a volume ratio of (20-25): 1 as an eluent, and concentrating under reduced pressure to obtain the tannin compound.

In a preferable mode, in step S1, the usage ratio of the total acanthus ilicifolius dry powder to the ethanol aqueous solution is 1g (4-8) mL.

In a preferred mode, in step S1, the concentration of the ethanol aqueous solution is 95 ± 2%.

In a preferable mode, in the step S1, the leaching time is 20 to 30 hours (a single time), and the leaching times are 1 to 3 times. When multiple leaching is adopted, the extracting solutions obtained by multiple leaching are combined, filtered and concentrated to obtain an extract.

In a preferred mode, in step S1, the concentration of the aqueous methanol solution is 80 ± 5%.

In a preferable mode, in step S1, the dosage ratio of the extract to the methanol aqueous solution is (300-400) g: 1L.

In a preferable mode, in step S1, the number of times of extraction is 2-4, and the ratio of the amount of petroleum ether used in each extraction to the amount of the aqueous methanol solution used in dispersion is (600-800) mL: 1L. When multiple extraction is adopted, the methanol phases obtained by multiple extractions are combined and then concentrated to obtain a methanol phase thick paste.

In a preferred mode, in step S2, the macroporous resin chromatographic column is an HP-20 macroporous resin chromatographic column.

In a preferable mode, in step S2, the methanol-phase thick paste is subjected to ultrasonic dissolution and dispersion by pure water, and then is subjected to sample loading, wherein the sample loading flow rate is 2-6 BV/h.

In a preferred mode, in step S2, water is used for elution to remove impurities before ethanol water solution is used for elution.

In a preferable mode, in step S3, the RP-18 reversed phase column has an inner diameter of 30 to 40mm and a length of 200 to 250 mm.

In a preferred embodiment, in step S4, the gel column is a Sephadex LH-20 gel column.

In a preferable mode, in step S5, the RP-18 reversed phase column has an inner diameter of 20 to 30mm and a length of 200 to 250 mm.

In a preferred embodiment, in step S6, the gel column is a Sephadex LH-20 gel column.

In the present invention, at step S2, the component a is a first active component (first-eluting component) enriched substance eluted from the macroporous resin chromatography column. In step S3, the component A3 is a third active component (third effluent component) enriched substance eluted from the RP-18 reverse phase column. In step S4, the fraction A3.1 is a first active fraction (first eluting fraction) enriched material eluted from the Sephadex LH-20 gel column. In step S5, the fraction A3.1.2 is a second active ingredient (second effluent) enriched material eluted from the RP-18 reverse phase column.

In addition, the invention also provides application of the tannin compound in anti-inflammation, hemostasis, antidiarrheal, antibacterial, antivirus, lipid peroxidation resistance, free radical scavenging, anti-mutation or anti-tumor.

The invention takes mangrove acanthus ilicifolius as raw material, adopts the way of matching several chromatographic separation technologies of macroporous resin, RP-18 reverse phase column, Sephedex LH-20 gel column and normal phase silica gel column to carry out separation and purification, and verifies that the obtained compound is a novel tannin compound by using modern wave spectrum technologies such as nuclear magnetism, mass spectrum and the like.

Tannins, also known as tannins or tannins, are natural polyphenol compounds with relatively complex structures existing in plants, are widely distributed in nature, and more than 70 percent of traditional Chinese medicines contain the tannins, so that the tannins have good biological and pharmacological activities. Historically, human use of tannins has been known for five thousand years ago: persistent diarrhea, dysentery, spontaneous sweating, night sweat caused by chronic disease, old age, and unconsolidation of primordial qi are used to astringe, astringe and relieve the loss of qi, blood and body fluids, and this treatment is called astringency therapy. Modern researches find that the tannin components in the astringent medicines are rich. In recent years, people make a great breakthrough in the research of tannin components in plants, and find that the tannin components not only have pharmacological activities such as anti-inflammation, hemostasis and antibiosis, but also have a plurality of pharmacological activities such as lipid peroxidation resistance, free radical scavenging, mutation resistance, tumor resistance and the like^[1-3]It is used clinically in stopping diarrhea, stopping bleeding, resisting virus and resisting bacteria^[4]。

Drawings

FIG. 1 is a Mass Spectrum (MS) of a tannin compound provided by the invention;

FIG. 2 is a heteronuclear single quantum correlation spectrum (HSQC) of the tannin compounds provided by the invention;

FIG. 3 shows the tannin compounds provided by the invention¹H-NMR chart;

FIG. 4 shows the tannin compounds provided by the invention¹³C-NMR chart;

FIG. 5 is a HMBC diagram of the tannins provided by the present invention;

FIG. 6 shows the tannin compounds provided by the invention¹H-¹H COSY picture.

Detailed Description

The following detailed description of embodiments of the invention is intended to be illustrative of the invention and is not to be construed as limiting the invention. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Examples

S1, drying 20kg of Acanthus ilicifolius, pulverizing, extracting with 6 times volume (mass volume ratio) of 95% ethanol aqueous solution at room temperature for three times (24 hr each time), and shaking. The extract is filtered and mixed by a Buchner funnel, and then is decompressed and concentrated at 45 ℃ to obtain 360g of extract. Dissolving the extract with 1L 80% methanol water solution, dispersing, extracting with 800mL, 600mL, and 600mL petroleum ether for three times, mixing petroleum ether solutions, concentrating under reduced pressure at 45 deg.C, and drying to obtain 14.3g petroleum ether phase. Filtering the methanol solution, concentrating the filtrate at 45 deg.C under reduced pressure until the methanol is completely distilled off to obtain methanol phase soft extract.

S2, adding pure water into the methanol-phase thick paste, ultrasonically dissolving and dispersing to about 2L, slowly pouring into a chromatographic column filled with 1L HP-20 macroporous resin, naturally flowing down at the flow rate of 4BV/h, and repeatedly loading the effluent into the column twice. Eluting with ultrapure water 2L to remove impurities, eluting with 30%, 50%, 70%, 95% ethanol water solution 4L in sequence, and collecting 1L per bottle. Four concentration gradients were collected in 4 vials each. The aqueous phase is discarded, other components are concentrated under reduced pressure at 45 ℃ and dried, a proper amount of methanol is dissolved and transferred to a 250mL concentration bottle, thin-layer chromatography TLC detection is carried out after the volume is adjusted to be basically consistent, and six components of a component A (14.3g, a collection bottle 1-3), a component B (6.4g, a collection bottle 4-6), a component C (1.9g, a collection bottle 7-10), a component D (0.7g, a collection bottle 11-13) and a component E (0.7g, a collection bottle 14-16) are combined according to the detection result. The basis for the combination is that the thin layer chromatography TLC detection results are close, and the same is shown below.

S3, dissolving component A (14.3g) with a small amount of methanol, separating with RP-18 reverse phase column (inner diameter 36mm, length 230mm), eluting with 2L of 15% and 30% acetone aqueous solution, and collecting 200mL portions per bottle. After concentrating the mixture to dryness under reduced pressure bottle by bottle, dissolving the mixture with methanol, transferring the mixture into a small test tube for thin layer chromatography TLC detection, and combining the detection results to obtain six components, namely a component A1 (collecting bottle 1), a component A2 (collecting bottle 2), a component A3 (collecting bottle 3-4), a component A4 (collecting bottle 5-7), a component A5 (collecting bottle 8-13) and a component A6 (collecting bottle 14-19).

S4, dissolving the component A3(1.7g) with a small amount of methanol, loading the solution on a Sephadex LH-20 gel column, eluting with methanol, adjusting the elution flow rate to 5-6 drops/min, and combining the components according to TLC detection results to obtain two components, namely a component A3.1(1.173g) and a component A3.2(534 mg).

S5, dissolving A3.1 with a small amount of methanol, loading the solution on an RP-18 reverse phase column (with the inner diameter of 26mm and the length of 230mm), eluting with 1.5L of 20% and 35% methanol respectively, collecting the solution in 100mL vials, decompressing and concentrating the solution bottle by bottle until the solution is dry, dissolving the solution in methanol, transferring the solution into a small test tube for Thin Layer Chromatography (TLC) detection, and combining the two components A3.1.1 (collecting bottle 1-5) and A3.1.2(353mg, collecting bottle 6-26) according to the detection result.

S6, dissolving A3.1.2 with methanol, performing Sephadex LH-20 gel column chromatography, eluting with an alcohol-ketone mixed solution composed of acetone and methanol according to a volume ratio of 3:1, concentrating the eluent under reduced pressure, performing normal phase silica gel column chromatography, eluting with an alcohol-hydrocarbon mixed solution composed of chloroform and methanol according to a volume ratio of 22:1, and concentrating under reduced pressure to obtain the tannin compound (36 mg).

The tannin compound is white amorphous powder, and is easy to be processedSoluble in methanol and acetone, insoluble in chloroform. The MS results of the tannin compounds are shown in FIG. 1, HSQC,¹H-NMR、¹³C-NMR、HMBC、¹H-¹The H COSY results are shown in fig. 2-6 and table 1, respectively.

In the context of figure 3, it is shown,¹H-NMR results showed the presence of two active hydrogens δ 12.81(brs) and δ 9.32(brs) and five aromatic protons in the low field region, where three aromatic protons δ 7.51(dd peak, J ═ 1.8/8.4), δ 7.38(d peak, J ═ 1.8) and δ 7.28(d peak, J ═ 8.4) constitute an ABX substitution (asymmetric trisubstitution) system of one benzene ring; a single peak containing two protons, δ 7.22, shows complete symmetry of benzene ring substitution. The presence of three methoxy groups can be judged by two methyl unimodal of the high field region, wherein delta 3.78 is two completely symmetrical and delta 3.52 is one.

In the case of figures 2 and 4 of the drawings,¹³C-NMR and HSQC results showed 23 carbon atoms with 3 methoxy groups, 1 oxygen substituted methine, 10 methine groups (5 aromatic rings and 5 sugar methine groups), 9 quaternary carbons (all aromatic rings or acyl quaternary carbons) indicating the presence of a glucose group.

In FIG. 5, a3 'methoxy-4' oxygen substituted benzoic acid structure is inferred from HMBC remote correlation of H-2 '(δ 7.38), H-5' (δ 7.28), H-6 '(δ 7.51) and H-3' a methoxy (δ 3.52); a3 "a, 5" a-dimethoxy substituted galloyl structure was determined by HMBC remote correlation of H-2 "(6") (Δ 7.22), H-3 "a (5" a) methoxy (Δ 3.78) and OH-4 "(Δ 9.32). In fig. 6, based on the remote correlation of glucose H-1(δ 5.35, peak d, J ═ 8.0) and H-2(δ 5.05), it was confirmed that glucose position 1 was linked to benzoic acid position 4' via a glycosidic bond, the glycosidic bond was in the β configuration, and glucose position 2 was linked to 3 "a, 5" a-dimethoxygalloyl group via an ester bond, thereby confirming that the tannin compound was 4- (4, 5-dihydroxy-3- (4-hydroxy-3, 5-dimethoxybenzoyloxy) -6- (hydroxymethyl) -tetrahydro-2H-pyran-2-acyloxy) -3-methoxybenzoic acid, which had the structure shown in formula (2). As shown in FIG. 1, molecular formula C was detected by mass spectrometry₂₃H₂₆O₁₃Completely matched with the molecular weight. The tannin compounds are new compounds after literature search.

TABLE 1 NMR data (ppm) of tannins

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[2]Shin Y,Shon M,Kim G,et al.Antioxidant and anti-adipogenic activities of persimmon tannins[J].Food Science and Biotechnology,2014,23(5):1689-1694.

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Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.