167 results about "Silica column" patented technology

The invention relates to the technical field of ferula asafoetida endophytic fungi separation and purification, in particular to alkaloid compounds in ferula asafoetida endophytic fungi as well as a preparation method and application of the alkaloid compounds in the ferula asafoetida endophytic fungi. And extracting with dichloromethane to obtain dichloromethane part extract, and purifying and separating the dichloromethane part extract by adopting silica gel column chromatography and high performance liquid chromatography to obtain the alkaloid compounds in the endophytic fungi of ferula sinkiangensis. The alkaloid compound in the ferula sinkiangensis endophytic fungi is disclosed for the first time, the compound is subjected to an in-vitro anti-tumor pharmacodynamic experiment, and according to the experiment result, the alkaloid compound has a certain inhibition effect on MCF-7 cells; therefore, the alkaloid compound can be used for preparing the medicine for preventing and treating the breast cancer, and a new medicine is provided for preventing and treating the breast cancer.

The invention relates to the technical field of photo-thermal therapy, in particular to a monomolecular photo-thermal agent with high photo-thermal conversion efficiency and a preparation method and application of the monomolecular photo-thermal agent. The preparation method comprises the following steps: S1, synthesis of a compound X1: under the protection of argon, dissolving 2, 4-dimethyl pyrrole in dichloromethane, stirring in an ice bath, adding trifluoroacetic anhydride, heating to room temperature after stirring, extracting after quenching reaction, combining organic phases, drying, filtering, concentrating under reduced pressure and purifying by silica gel column chromatography to obtain the compound X1. The prepared monomolecular photothermal agent with the high photothermal conversion efficiency is high in water solubility, has the high photothermal conversion efficiency in an aqueous solution and is high in light stability, the immune escape phenomenon possibly caused by introduction of a high polymer material is avoided, and the technical problem that an existing photothermal agent is difficult to achieve the high photothermal conversion efficiency in the aqueous solution is solved.

The invention belongs to the technical field of agricultural chemistry, and particularly relates to a naphthoquinone compound with tobacco black shank resisting activity as well as a preparation method and application of the naphthoquinone compound. The naphthoquinone compound is prepared by the following steps: by taking honeysuckle branches as raw materials, extracting with high-concentration methanol, high-concentration acetone / water or high-concentration ethanol / water, merging extracting solutions, filtering, and concentrating under reduced pressure to obtain extract; packing the extract by using a silica gel dry method and carrying out silica gel column chromatography; carrying out gradient elution by using a chloroform-acetone solution; and further separating and purifying the 7: 3 part of the eluent by high performance liquid chromatography to obtain the required naphthoquinone compound. The invention further discloses application of the compound, and activity tests show that the compound has a good inhibiting effect on tobacco black shank. The compound disclosed by the invention is novel in structure, has relatively good black shank resisting activity, can be used as a lead compound for resisting tobacco black shank, and is used for research and development of biological pesticides for preventing and treating tobacco black shank.

The invention belongs to the technical field of phytochemistry, and particularly relates to a benzo [e] pyrrolo [1, 2-a] aza # imgabs0 # compound as well as a preparation method and application thereof. The preparation method comprises the following steps: fermenting cigar stem barks, drying the fermented cigar stem barks in the sun, crushing and sieving to obtain a material a; adding a first solvent into the material a for reflux extraction to obtain an extracting solution, concentrating the extracting solution, adding a second solvent for extraction, combining the extracted extraction phases, and performing vacuum concentration to obtain an extract b; carrying out silica gel column chromatography on the extract b, eluting with chloroform-acetone eluent, monitoring by TLC (Thin Layer Chromatography), and collecting the eluent; and purifying the eluent by using a sephadex column, and separating and purifying by using high performance liquid chromatography to obtain the benzo [e] pyrrolo [1, 2-a] aza # imgabs 1 # compound with tobacco black shank resisting activity. The compound is novel in structure, has relatively good black shank resistance activity, can be used as a lead compound for resisting tobacco black shank, and is used for research and development of biological pesticides for preventing and treating tobacco black shank.

The invention relates to the technical field of biological medicines, in particular to a polycyclic polyisopentenyl cyclopentanone compound as well as a preparation method and application thereof. The polycyclic polyisopentenyl cyclopentanone compound provided by the invention has a structural formula as shown in a formula 1; the preparation method comprises the following steps: by taking dry fruits of hypericum berry as raw materials, carrying out percolation extraction and concentration to obtain an extract, suspending the extract in water to obtain a suspension, and extracting and concentrating the suspension with petroleum ether to obtain a crude extract; the crude extract is taken and subjected to positive and negative phase silica gel column separation, MCI medium-pressure column chromatography, Sephadex LH-20 gel column chromatographic separation, high performance liquid chromatography preparation and CHIRALPAK IG chiral column resolution, and the polycyclic polyisopentenyl cyclopentanone compound is obtained. The protection activity of the compound on AC16 myocardial cell injury induced by cold ischemia is evaluated, and the compound can be used for preparing the polycyclic polyisopentenyl cyclopentanone compound. The compounds can be used as lead compounds for developing medicines for preventing and treating myocardial cold ischemia injury.

The invention belongs to the technical field of natural pharmaceutical chemistry, and discloses a benzofuran compound in dalbergia odorifera and a preparation method and application thereof.The benzofuran compound is separated from dalbergia odorifera of a leguminous dalbergia plant, the heartwood of the dalbergia odorifera is extracted and concentrated to obtain extract, and the extract is filtered to obtain the benzofuran compound. The extract is taken and sequentially subjected to silica gel column chromatography, medium-pressure ODS column chromatography and gel column chromatography separation for multiple times, then semi-preparative high performance liquid chromatography is used for purification, and the benzofuran compounds can be obtained. According to the present invention, lipopolysaccharide (LPS) is adopted to induce RAW 264.7 cells to establish an inflammation model, such that the compound has good anti-inflammatory activity, IC50 is 14.33 [mu] M, and expression of inflammatory factor interleukin-6 (IL-6) and interleukin-1 [beta] (IL-1 [beta]) can be inhibited;

The application belongs to the technical field of natural medicinal chemistry, and discloses a benzofuran compound in Jinyunming and a preparation method and application thereof. The benzofuran compound is separated from Jinyunming of the plant Dalbergia hupeana Tutch in the family of Leguminosae. The heartwood of Jinyunming is extracted and concentrated to obtain extract, the extract is sequentially separated by multiple silica gel column chromatography, medium-pressure ODS column chromatography and gel column chromatography, and then purified by semi-preparative high-performance liquid chromatography, so that the benzofuran compound can be obtained. The application establishes an inflammation model by inducing RAW 264.7 cells with lipopolysaccharide (LPS), and shows that the compound has good anti-inflammatory activity, the IC50 is 14.33 μM, and the expression of inflammatory factors interleukin-6 (IL-6) and interleukin-1β (IL-1β) can be inhibited.

The invention belongs to the technical field of natural pharmaceutical chemistry, and particularly relates to a novel iridoid compound, namely, uncarcinin, separated from wingceltis, a pharmaceutically acceptable isomer of the novel iridoid compound, a wingceltis extract containing the novel iridoid compound, and a preparation method and application of the novel iridoid compound. The chemical structure of the utazonine is shown as a formula I, and the absolute configuration of the utazonine is (1S, 3S, 3aR, 4R, 7aS). The invention also provides a method for extracting the compound or the extract from the stem of the wingceltis, and purifying by combining pH gradient extraction with silica gel column chromatography, semi-preparative high performance liquid chromatography and gel chromatography to obtain the compound or the extract. The wingceltis cycline, the isomer of the wingceltis cycline, the wingceltis extract containing the wingceltis cycline or the pharmaceutical composition show remarkable gastric mucosa protection activity in an in-vitro cell model, particularly, the protection rate of the wingceltis cycline to ethanol-induced human gastric mucosa epithelial cell (GES-1) injury at the concentration of 50 mu M can reach 5.21%, and the wingceltis cycline, the isomer of the wingceltis cycline, the wingceltis extract containing the wingceltis cycline or the pharmaceutical composition show definite gastric mucosa protection activity.

This invention relates to a novel substance with in vitro anti-inflammatory activity, its preparation method, and its application. The chemical name of maltol-3-1'-ethoxyhexane-1”,2”,3”,4”,5”,6”-hexaol-(4'-2”)-glucopyranoside is C. 21 H 34 O 13 Preparation method: 1. Extract *Trollius chinensis* with 70% ethanol (v / v); 2. Concentrate the extract until no alcohol odor remains and load it onto a D101 macroporous resin column; 3. Elute the fraction from the D101 macroporous resin with 30% ethanol, separate by silica gel column chromatography and gel column chromatography, and then obtain *Trollius chinensis* glycoside C using high-performance liquid chromatography. *Trollius chinensis* glycoside C is used to prepare anti-inflammatory drugs. The IC50 of *Trollius chinensis* glycoside C in this invention inhibits the release of pro-inflammatory factors TNF-α and IL-6 from LPS-stimulated mouse macrophages (RAW264.7). 50 The concentrations were 22.8 μmol / L and 31.0 μmol / L, respectively, indicating that it has good in vitro anti-inflammatory activity. This invention belongs to the field of research on effective components of natural drugs.

The present invention discloses a sesquiterpene glycoside compound and its preparation method and application. A new sesquiterpene glycoside ligulariatinside A is isolated and identified from the n-butanol extraction part of 95% ethanol extract from the root of Ligularia glossata by multiple chromatographic methods such as macroporous resin column chromatography, positive and reverse phase silica gel column chromatography and high performance liquid chromatography, as well as spectral methods. The molecular formula of the new sesquiterpene glycoside ligulariatinside A is determined to be C 21 H 34 O7, the structure is (3 S ,4 R ,5 R ,7 R )‑11‑hydroxy‑11,12‑dihydronootkatone‑11‑ O ‑ β ‑D‑glucopyranoside enriches the chemical diversity of Ligularia officinalis. Bacterial inhibition experiments revealed that the new sesquiterpenoid glycoside exhibits inhibitory activity against Vibrio anguillarum, with a minimum inhibitory concentration (MIC) of 50 μg / mL, laying the foundation for the development of new antibacterial drugs.

The invention discloses a high-yield method for reducing dinitro and retaining sensitive protecting groups, which comprises the following steps: adding water, sodium dithionite and sodium carbonate into a container, stirring and clarifying, and dropwise adding a mixed solution containing raw materials; after the reaction is finished, extracting, separating liquid, concentrating, and purifying by silica gel column chromatography to obtain a product and a byproduct; the raw material is a compound containing a carbon-carbon double bond, a p-methoxybenzyl protecting group, a t-butyloxycarboryl protecting group and dinitro. Adding a byproduct into a phosphoric acid mixed solution for reaction; and after the reaction is finished, adding dichloromethane and water, dropwise adding triethylamine to adjust the pH value, extracting, separating liquid, drying, concentrating, and purifying by silica gel column chromatography to obtain the product. According to the method, a sodium hydrosulfite / sodium carbonate system and phosphoric acid step-by-step treatment strategy is adopted, reduction of dinitro is achieved under mild conditions, meanwhile, PMB protecting groups, Boc protecting groups and C-C double bonds are reserved, and the problem that stability and high yield of the protecting groups cannot be considered at the same time in an existing method is solved.

The invention discloses a universal polymer force-sensitive cross-linking agent based on combination of a force-sensitive group and a bis-aziridine cross-linking function, and a preparation method and application thereof. The cross-linking agent is prepared by esterification of the force-sensitive group and a bis-aziridine group. The method comprises the following steps: in a nitrogen environment, carrying out a reaction on a force sensitive group, 4-[3-(trifluoromethyl) diazo-3-yl] benzoic acid, 4-dimethylaminopyridine (DMAP) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC-HCl) in anhydrous dichloromethane; and extracting the obtained mixture for three times, performing column chromatography purification on the obtained mixture on a silica gel column by using an eluent, and spin-drying to obtain a final product. The mechanical response sensitivity and structural stability of the material are remarkably improved, a mechanical force sensitive group introduction strategy suitable for various polymer systems is established, and a new technical path and theoretical support are provided for multifunctional design and wide application of the stress sensitive material.

The invention discloses a method for preparing lobster sarcosinine by using nereis as a raw material, and the lobster sarcosinine is prepared by adopting a combined process of reverse phase silica gel column chromatography, gel column chromatography, normal phase silica gel column chromatography and HPLC (High Performance Liquid Chromatography) preparation. Compared with a traditional lobster extraction method for preparing lobster sarcosinine, the method provided by the invention can realize high-purity separation of a target product; and the methanol solvent used in the process can be recycled through distillation, thereby conforming to the concept of green production. Therefore, deep development and efficient utilization of marine resources can be promoted, natural marine drug resource reserve is enriched, a new direction is provided for research and application in the fields of healthy development of human beings and disease prevention and control, and remarkable social benefits are achieved.

The invention belongs to the technical field of silica gel rod production, and discloses a full-automatic silica gel rod assembling machine which comprises a production workbench, and further comprises a conveying assembly, a feeding assembly and a discharging assembly, the silica gel column assembling component is mounted at the top of the production workbench and is used for assembling silica gel rods step by step; the pressing assembly is mounted at the top of the conveying assembly and used for pressing and fixing the silica gel rod; through cooperation of structures such as the first visual detector and the second visual detector, whether assembling is correct or not can be conveniently confirmed, the first visual detector is installed between the first assembling mechanism and the second assembling mechanism so as to conduct visual detection on the assembled products at each station, and the assembling efficiency is improved. Therefore, it is guaranteed that products in each assembly process can be detected, the overall quality is guaranteed, and meanwhile through the arrangement of the second visual detector, visual detection can be conducted on the gear of the shaft sleeve before the gear of the shaft sleeve is installed.

The invention relates to the technical field of agriculture, and provides germacane type sesquiterpenoids in tithonia diversifolia as well as a preparation method and application thereof.The preparation method comprises the steps that stem and leaf parts of tithonia diversifolia are subjected to ethanol cold-soaking extraction, and an extracting solution is subjected to vacuum concentration to obtain a total extract; suspending the total extract with water, sequentially extracting with petroleum ether and ethyl acetate, and concentrating the extract liquor under reduced pressure to obtain each extraction layer; carrying out silica gel column chromatography separation on the ethyl acetate extraction layer, and combining to obtain six parts A-F; carrying out MCI column chromatography separation on the part D, and combining to obtain thirteen parts D1-D13; carrying out silica gel column chromatography separation on the D9 part, and combining to obtain fifteen parts D91-D915; and separating the D915 part by adopting HPLC (High Performance Liquid Chromatography) to prepare two germacane type sesquiterpenoids. The preparation method disclosed by the invention is simple and good in reproducibility, and the prepared germacane type sesquiterpenoids are high in purity and have specific herbicidal activity on foreign invasive plants such as ambrosia trifida and ambrosia esculenta.

This invention discloses a strain of *Carya volvacea* ZZNS-Y2 and its applications, belonging to the field of microbial application technology. The *Carya volvacea* (… Daldinia sp. The preservation number of ZZNS-Y2 is CCTCC NO: M 20241561. The method includes the following steps: *Cyclocarya paliurus* ZZNS-Y2 is cultured on one of the following solid-state fermentation media: corn, potato, corn grits, or rice. After extraction and concentration, the compounds crocusatin C and jasminodiol are separated by silica gel column chromatography, gel column chromatography, and high-performance liquid chromatography. The method of this invention is efficient, pollution-free, has mild reaction conditions, is not limited by plant resources, and is easy to scale up for production.

The invention discloses a compound with remarkable 5-hydroxytryptamine (5-HT) reuptake inhibition activity, a preparation method of the compound and application of the compound in preparation of anti-depression drugs. And the compound is a compound Oreonudine C. The invention further discloses a preparation method of the compound. The preparation method of the Oreonudine C comprises the following steps: extracting with 95% ethanol, acidifying the extract, extracting with petroleum ether, adjusting the acid water layer to be alkaline with alkali liquor, extracting with chloroform, and performing silica gel column chromatography, C18 ODS column chromatography and preparative high performance liquid chromatography on the chloroform extraction part to obtain the Oreonudine C. The invention further discloses a preparation method of the Oreonudine C. The preparation method of the Oreonudine C comprises the following steps: extracting with 95% ethanol, acidifying the extract, extracting with petroleum ether, adjusting the acid water layer to be alkaline with alkali liquor, and obtaining the Oreonudine C. In-vitro experiments show that the compound Oreonudine C remarkably inhibits reabsorption of 5-HT (the inhibition rate is 60.4%) in mouse hippocampal neuronal cells HT22, and the inhibition rate of the compound Oreonudine C is superior to that of a positive control drug amitriptyline (the inhibition rate is 53.6%). The invention provides an important candidate compound for developing efficient and novel antidepressant drugs.

The utility model discloses a coating head exhaust air automatic adjusting device which comprises a filter assembly, and the filter assembly comprises a first activated carbon filter screen, a second activated carbon filter screen, a connecting frame, a fixing rod and a silica gel column. By means of the filter assembly, when the air inlet sucks air, adsorbed air is filtered under the design of the first activated carbon filter screen and the second activated carbon filter screen, and when the pipeline type air speed sensor detects that the air speed in the air inlet is abnormal, the air inlet is opened, and the air inlet is closed. If the first activated carbon filter screen and the second activated carbon filter screen need to be replaced, when the first activated carbon filter screen and the second activated carbon filter screen need to be replaced, the first activated carbon filter screen can move downwards after a screw is rotated out of a mounting column and a connecting rod is not limited, and the second activated carbon filter screen can move downwards after the first activated carbon filter screen and the second activated carbon filter screen are separated from the interior of the tuyere; an inward extrusion force is applied to the movable column to drive the silica gel column to be separated from the interior of the connecting frame, and then an upward pulling force is applied to the second activated carbon filter screen.

The application belongs to the technical field of agricultural chemistry, and particularly relates to a naphthoquinone compound with anti-tobacco black shank disease activity and a preparation method and application thereof. The naphthoquinone compound is extracted from honeysuckle branches with high-concentration methanol, high-concentration acetone / water or high-concentration ethanol / water, the extract is combined, filtered, and concentrated into an extract under reduced pressure; the extract is subjected to silica gel column chromatography by dry column packing with silica gel; gradient elution is performed with chloroform-acetone solution; and the 7:3 part of the eluate is further separated and purified by high-performance liquid chromatography to obtain the required naphthoquinone compound. The application also discloses the application of the compound. The active test shows that the compound has a good inhibitory effect on tobacco black shank disease. The compound has a novel structure, good anti-black shank disease activity, and can be used as a lead compound for anti-tobacco black shank disease and for the research and development of anti-tobacco black shank disease biological pesticides.

The present application relates to a method for purifying rubitecan and its intermediates. The method is simple, low cost, high yield, suitable for industrial production, and avoids the uncertainty of silica gel column chromatography purification.

The invention belongs to the technical field of fluorescent dyes, and particularly relates to a phenanthroline-based double-BODIPY fluorescent dye with an asymmetric structure as well as a preparation method and application of the phenanthroline-based double-BODIPY fluorescent dye. The preparation method comprises the following steps: mixing a chlorinated BODIPY derivative with 1, 10-phenanthroline-5-amino, adding palladium acetate, tri-tert-butylphosphine, potassium tert-butoxide and toluene, and carrying out a heating reflux reaction; and after the reaction is finished, cooling, reducing pressure to remove toluene, dissolving the obtained product with dichloromethane, washing, drying, concentrating, and separating and purifying through silica gel column chromatography to obtain the target dye. The unique asymmetric structure in the prepared target dye destroys the planarity and symmetry of molecules, effectively weakens the fluorescence quenching effect caused by molecular self-absorption and pi... pi accumulation, and further has relatively large Stokes shift and high solid-state luminous efficiency; good application potentials are shown in a plurality of fields such as high-performance solid-state light-emitting devices and biological probes.

The utility model discloses a road roller with a pressure supplementing structure, which relates to the technical field of road rollers and comprises a tamping device, a support plate is fixedly mounted on one side of the top inside the tamping device, an energy accumulator is fixedly mounted on the top of the support plate, a tamping oil cylinder is fixedly mounted on the top inside the tamping device, and a pressure supplementing device is fixedly mounted on the tamping oil cylinder. A hammer head is fixedly installed at the bottom of the tamping oil cylinder, and a speed limiting device is fixedly installed at the bottom of one side in the tamping device. According to the road roller with the pressure supplementing structure, vibration of the supporting frame can be reduced through a rubber plate, a camera can be buffered and damped through a silica gel column and a spring in the silica gel column, and therefore the problems that the camera is damaged due to vibration and shooting is not clear due to shaking are solved; a compacting process route is collected in real time through the camera and the GPS system and uploaded to the server to evaluate the compacting effect of the roadbed, so that the problem of pressure leakage is avoided, and meanwhile, the pressure supplementing operation can be performed on the road surface with pressure leakage.

This invention relates to the field of pharmaceutical analysis technology, specifically to a method for determining the content of deoxycholic acid injection. The detection method employs high-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector. The HPLC chromatographic conditions are as follows: the column is an octadecylsilane-bonded silica column; the column dimensions are 4.6 × 150 mm, and the packing diameter is 3 μm; the detection wavelength is 220 nm; the mobile phase is 0.1% formic acid aqueous solution – 0.1% formic acid acetonitrile solution (42:58). Compared with existing technologies, UV detectors are more readily available than CAD detectors. This invention achieves quantitative detection of deoxycholic acid injection content by controlling the HPLC conditions of the UV detector. This method exhibits baseline stability, good specificity, accuracy, and precision, and is of significant importance for the quality control of deoxycholic acid injection.

The invention relates to the related technical field of measurement of the content of fluticasone propionate emulsifiable paste, in particular to a method for detecting the content of paste by adopting a high performance liquid chromatography, and particularly relates to a method for measuring the content of fluticasone propionate emulsifiable paste by adopting the high performance liquid chromatography, in particular to a method for detecting the content of fluticasone propionate emulsifiable paste by adopting the high performance liquid chromatography. Comprising the following steps: preparing a mobile phase from a diammonium hydrogen phosphate buffer solution (the pH value is 2.0-5.0), methanol and acetonitrile by adopting an octadecyl silane bonded silica gel column; and carrying out isocratic elution. According to the method disclosed by the invention, the diammonium hydrogen phosphate buffer solution-methanol-acetonitrile with a specific ratio is adopted as a mobile phase, and a chromatographic system in which an octadecyl silane bonded silica gel column and a guard column are connected in series is combined, so that the interference of oily auxiliary materials in a cream matrix is effectively eliminated, and the detection specificity and the separation effect are remarkably improved; besides, key chromatographic parameters such as column temperature, flow velocity and detection wavelength are optimized, and a scientific test sample pretreatment process is matched, so that the accuracy and reliability of a content measurement result are guaranteed.

The invention discloses a method for separating and purifying flaxseed mixed cyclopeptides with different oxidation degrees. The inventor develops a two-step silica gel-phenylethyl mixed cyclopeptide separation method by optimizing the separation conditions of rapid liquid chromatography through a large amount of research and combining normal-phase silica gel column separation and reverse-phase phenylethyl column separation, and the method can be applied to separation of flaxseed mixed cyclopeptides from different sources, and has the advantages of simple operation and high efficiency. And mixed cyclic peptides extracted from linseed oil with different oxidation degrees can be treated, so that a high-purity linseed cyclic peptide fraction is obtained.

This invention relates to the fields of biomedicine and microbial fermentation engineering technology, and discloses a strain of *Streptomyces citrus* YS-4 that produces mesocyclocarpine. The separation and purification process includes: solid-liquid separation of the fermentation broth; extraction of the supernatant with ethyl acetate and extraction of the bacterial cells by methanol soaking; combining and concentrating the extracts to obtain a crude extract; purification of the crude extract by silica gel column chromatography and Sephadex LH-20 gel column chromatography; and finally purification by C18 reversed-phase semi-preparative high-performance liquid chromatography to obtain mesocyclocarpine. This invention employs a dual extraction strategy to improve the yield and achieves efficient separation of the target product and its structural homologues through specific chromatographic conditions, effectively solving the problem of incomplete extraction caused by the coexistence of intracellular adsorption and extracellular secretion of the target product, resulting in a final product yield superior to that of single-solvent extraction methods.

The invention provides a method for detecting the content of compound selamectin drops, which adopts high performance liquid chromatography for detection, and comprises the following specific steps: sequentially preparing a blank solution, a blank auxiliary material solution, a contrast solution and a test solution, sequentially and respectively injecting the blank solution, the blank auxiliary material solution, the contrast solution and the test solution into a high performance liquid chromatograph, an octadecyl silane bonded silica gel column is used as a chromatographic column, a formic acid solution is used as a mobile phase A, acetonitrile is used as a mobile phase B, and gradient elution is carried out. According to the method disclosed by the invention, the three active ingredients, namely the selamectin, the fluralan and the praziquantel, in the compound selamectin drops can be effectively detected, the quality detection result is accurate and reliable, and the three active ingredients in the compound selamectin drops can be accurately quantified, so that the product quality of the compound selamectin drops can be better controlled.

The present application provides a new Chaetomium sp. strain, which is preserved in China General Microbiological Culture Collection Center (CGMCC) with a preservation number of CGMCC NO.23896; the present application also provides a new compound shown as formula I produced by solid fermentation of the strain, wherein the compound has stable performance, no cytotoxicity, and significant neuroprotective activity; the compound can be obtained by ethyl acetate extraction on the fermentation product of the aforementioned strain, followed by silica gel column chromatography and high performance liquid chromatography separation and purification, and the separation steps are simple, easy to implement, easy to mass produce in industry, and have broad application prospects.

The utility model relates to the technical field of placing frames, and discloses an optical lens detection placing frame which comprises a base, supporting legs are fixedly installed at the top of the base, a shell is fixedly installed at the tops of the supporting legs, and a placing cushion block is fixedly installed at the top of the shell. The interior of the shell and the top of the base are each provided with a three-point synchronous clamping mechanism, and the tops of the three-point synchronous clamping mechanisms are provided with installation buffering mechanisms. According to the optical lens detection placing frame, the contact stress is reduced by arranging the installation buffer mechanism and arranging an elastic buffer structure at a clamping point, the strain pressure is effectively reduced by utilizing a combined double-layer buffer structure of a spring and a silica gel column, and lens deformation caused by overlarge local stress is prevented; the situation that the detection precision is affected after the lens is deformed is avoided, meanwhile, the installed buffering mechanism can be integrally replaced at any time through bolts, and it is guaranteed that the buffering mechanism can be kept in a stable state all the time.

The application relates to a kind of isoprenyl xanthone compounds and preparation method and application thereof, relate to the medical technical field, comprising the following steps: 1) after cutting, cold extraction of the whole herb of Eupatorium fortunei, filtrate is collected and concentrated under reduced pressure to obtain extract;2) the extract obtained in step 1) is chromatographed by silica gel column, gradient elution is carried out, and 3 fractions Fr.A-Fr.C are obtained;3) fraction Fr.A in step 2) is chromatographed by MCI column, gradient elution is carried out, and 6 fractions Fr.A1-Fr.A6 are obtained;4) fraction Fr.A3 in step 3) is chromatographed by silica gel column, gradient elution is carried out, and 11 fractions Fr.A3.1-Fr.A3.11 are obtained;5) compound is prepared and separated by HPLC high performance liquid chromatography method in fraction Fr.A3.10 in step 4), for preparing the drug for resisting Alzheimer disease.