An iridoid ether with antioxidant activity and its application

Abstract

This invention discloses an cycloene ether terpene with antioxidant activity and its application. The cycloene ether terpene with antioxidant activity has the structure shown in formula (I). Experiments have shown that the cycloene ether terpene with antioxidant activity shown in formula (I) of this invention has significant antioxidant activity and can be used in the preparation of antioxidant drugs or cosmetics.

Description

Technical Field

[0001] This invention relates to an iridoid ether terpene with antioxidant activity extracted from plants and its applications. Background Technology

[0002] *Lancea tibetica* Hook.f.et Thoms, a plant belonging to the genus *Lancea* in the family Scrophulariaceae, is transliterated from Tibetan as Bayaba or Wayaba. It is widely distributed in Qinghai Province, my country, primarily growing in alpine thickets, meadows, floodplains, and sparse forest edges at altitudes of 2000–4500 m. In Tibetan medicine, it is considered a superior herb; the whole plant can be used for clearing heat, relieving cough, stopping phlegm, and eliminating pus. Its roots, leaves, and seeds are used to treat leukemia, colic, heart disease, and coughs.

[0003] Currently, there are no reports on the extraction and isolation of the iridoids of this invention from *Hedyotis diffusa*, or their application in the preparation of antioxidant drugs or antioxidant cosmetics. Summary of the Invention

[0004] The first objective of this invention is to utilize traditional Chinese medicinal materials to isolate and extract an iridoid ether terpene with antioxidant activity.

[0005] A second objective of this invention is to provide the application of iridoids with antioxidant activity in the preparation of antioxidant drugs or antioxidant cosmetics.

[0006] The technical solution of this invention is summarized as follows:

[0007] An cyclohexene ether with antioxidant activity, as shown in Formula I:

[0008]

[0009] The above-mentioned iridoid ether with antioxidant activity is used in the preparation of antioxidant drugs or antioxidant cosmetics.

[0010] Advantages of this invention:

[0011] Experiments have shown that the iridoid ether terpene of Formula I of the present invention has significant antioxidant activity and can be used in the preparation of antioxidant drugs or antioxidant cosmetics. Detailed Implementation

[0012] The present invention will be further described below through specific embodiments.

[0013] Example 1

[0014] Extraction and separation of an iridoid ether with antioxidant activity

[0015] Take 7.8 kg of whole plant of *Hedyotis diffusa* and soak it in 95% ethanol aqueous solution at room temperature for 2 weeks. Filter to obtain medicinal residue and filtrate. Soak the medicinal residue in 95% ethanol aqueous solution and heat and reflux twice for 2 hours each time to obtain extract 1. Then soak it in 60% ethanol aqueous solution and heat and reflux twice for 2 hours each time to obtain extract 2. Combine the filtrate, extract 1 and extract 2, and concentrate under reduced pressure to obtain crude extract (2.9 kg). Suspend the crude extract with 8 L of distilled water and extract with petroleum ether and ethyl acetate in sequence. Recover the solvent to obtain ethyl acetate extract (670 g).

[0016] The ethyl acetate extract (650 g) was separated by silica gel column chromatography using a gradient elution with dichloromethane-methanol at volume ratios of 100:0, 98:2, 94:6, 90:10, 84:16 and 74:26. ​​One fraction was collected for each 500 ml fraction, resulting in a total of 163 fractions (A1 to A163).

[0017] By silica gel TLC analysis, 23.2 g of similar fractions A116 to A119 were combined and separated by silica gel column chromatography. Gradient elution was performed using dichloromethane-methanol eluents with volume ratios of 92:8, 90:10 and 88:12, and one fraction was collected for every 250 ml, resulting in a total of 55 fractions (B1 to B55).

[0018] By silica gel TLC analysis, 11.3 g of similar fractions B20 to B53 were combined and separated by polyamide column chromatography. The fractions were eluted by gradient elution with dichloromethane-methanol at volume ratios of 96:4, 94:6, 92:8 and 90:10, and one fraction was collected for every 200 ml, resulting in a total of 100 fractions (C1 to C100).

[0019] By silica gel TLC analysis, 2.4 g of similar fractions C39 to C48 were combined and separated by Sephadex LH-20 column chromatography with methanol as the eluent for isocratic elution. One fraction was collected for every 8 ml, resulting in 20 fractions (D1 to D20).

[0020] Analysis by silica gel TLC revealed that 1.8 g of similar fractions D4–D10 were combined and subjected to preparative MPLC chromatography with methanol-water (42:58) as the mobile phase to obtain compound 1 (80 mg, t). R =200min).

[0021] By analyzing the structures of each compound using physicochemical constants and modern spectroscopic techniques, it was confirmed that compound 1 is a new compound, 7-OE-caffeoyl geniposide.

[0022] The structural formula of compound 1 is shown in Formula I.

[0023]

[0024] The physical constants of the new compound are as follows:

[0025] Compound 1: White amorphous powder; UV (methanol)λ max (logε):235(1.14),325(1.08)nm; IR(KBr)ν max :3300,2930,1680,1625,1590,1512cm -1 ;(+)-HR-ESI-MSm / z 573.1581[M+Na] + (The calculated value is 573.1579), and the molecular formula is determined to be C. 26 H 30 O 13 ; 1 H NMR (600MHz, CD3OD) and 13 The C NMR (150MHz, CD3OD) data are shown in Table 1.

[0026] Table 1 Compound 1 1 H NMR and 13 C NMR data (600 / 150MHz, CD3OD)

[0027]

[0028] Example 2

[0029] The antioxidant capacity of the compounds was determined by the DPPH (1,1-diphenyl-2-trinitrophenylhydrazine) method. A 120 μM DPPH solution (ethanol as solvent) was prepared, and the test samples were prepared into sample solutions (methanol as solvent) with different concentration gradients (10, 25, 50, 75, 100, 150, 200 μg / mL).

[0030] Add 0.1 mL of sample solution and 0.1 mL of DPPH solution to a test tube and shake well. After storing at room temperature in the dark for 30 minutes, measure the absorbance at a UV wavelength of 517 nm. Each sample was measured in triplicate, and the average value was taken. Vitamin C (water-soluble) was used as a positive control in this experiment. Calculate the scavenging rate of DPPH free radicals for each test sample according to formula (1).

[0031]

[0032] In the formula:

[0033] As represents the absorbance of a mixture of 0.1 mL of sample solution and 0.1 mL of DPPH solution;

[0034] Asb is the absorbance of the mixture of 0.1 mL sample solution and 0.1 mL anhydrous ethanol;

[0035] Ac is the absorbance of the mixture of 0.1 mL water and 0.1 mL DPPH solution;

[0036] Acb is the absorbance of a mixture of 0.1 mL water and 0.1 mL anhydrous ethanol.

[0037] Based on the calculated clearance rate and the fitted curve with the sample solution concentration, the IC50 was obtained. 50 Value. Experiments have shown that the above compounds have significant antioxidant activity and can be used in the preparation of cosmetics and pharmaceuticals.

[0038] Results of in vitro antioxidant activity assay of compound 1

[0039]

[0040] From the data above, we can see that compound 1 has significant antioxidant activity.

Claims

1. A cyclohexene ether terpene with antioxidant activity, characterized in that... The structure is shown in equation (I):

2. The use of the iridoid ether terpene with antioxidant activity according to claim 1 in the preparation of antioxidant drugs or antioxidant cosmetics.

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