Abstract: Disclosed in the present application are a dexmedetomidine transdermal composition, a transdermal patch and a preparation method therefor and the use thereof. The composition comprises dexmedetomidine, propylene glycol, and a metal chelate crosslinking agent, or dexmedetomidine, propylene glycol, a metal chelate crosslinking agent and a pressure-sensitive adhesive. In addition, according to the present application, propylene glycol is added to the dexmedetomidine transdermal composition as a solubilizer, which can reduce the generation of impurities and make the compatibility of raw materials and auxiliary materials better. Moreover, the skeleton structure of the product is constructed using the metal chelate crosslinking agent and the pressure-sensitive adhesive together, so that the adhesion performance is obviously improved, and patients can achieve an excellent fitting feeling.

Abstract: A method for measuring aloesin in rat plasma includes: taking the to-be-detected plasma containing aloesin, adding the methanol solution containing the internal standard compound aloeresin D thereinto, performing vortex precipitation, centrifuging, and collecting supernatant as to-be-detected sample; setting liquid chromatogram conditions as follows: carrying out gradient elution by adopting a mobile phase A and a mobile phase B, wherein the mobile phase A is an aqueous solution containing 0.1-1.0 thousandth (v/v) of formic acid, the mobile phase B is methanol; Setting mass spectrometry conditions as follows: using electrospray ion source, using negative ion detection, spray voltage being 4500 V, spray temperature being 550° C.; adopting multiple reaction ion monitoring scan mode, wherein the ion pair used for the quantitative analysis of aloesin is m/z 393.1?272.9, and the ion pair for the internal standard compound aloeresin D is m/z 555.3?144.9. The method improves aloesin detection in plasma.

Abstract: In the technical field of plant medicines, disclosed is the application of aloesin in the preparation of products for preventing or treating obesity. Research has found that aloesin can inhibit lipid accumulation, increase the expression of browning genes UCP1 and PRDM16 and transcription factor C-EBPa, increase the expression and release of specific factor adiponectin, and inhibit the release of non-specific factor IL-1?, indicating that aloesin can mediate the browning of 3T3-L1 adipocytes, and aloesin can be used to prepare products for preventing or treating obesity.

Abstract: A method for measuring aloesin in rat plasma includes: taking the to-be-detected plasma containing aloesin, adding the methanol solution containing the internal standard compound aloeresin D thereinto, performing vortex precipitation, centrifuging, and collecting supernatant as to-be-detected sample; setting liquid chromatogram conditions as follows: carrying out gradient elution by adopting a mobile phase A and a mobile phase B, wherein the mobile phase A is an aqueous solution containing 0.1-1.0 thousandth (v/v) of formic acid, the mobile phase B is methanol; Setting mass spectrometry conditions as follows: using electrospray ion source, using negative ion detection, spray voltage being 4500 V, spray temperature being 550° C.; adopting multiple reaction ion monitoring scan mode, wherein the ion pair used for the quantitative analysis of aloesin is m/z 393.1?272.9, and the ion pair for the internal standard compound aloeresin D is m/z 555.3?144.9. The method improves aloesin detection in plasma.

Abstract: Disclosed is a 5-methylchromone and the preparation method and application thereof, the 5-methylchromone has the following structure: wherein R1 and R2 are alkyl groups. The substituted chromone has the biological activity of inhibiting tyrosinase. The preparation method uses 3,5-dihydroxytoluene as a raw material, and synthesis of chromones substituted with different groups at 2-C through acylation, esterification, rearrangement and cyclization reactions, etc. The 5-methylchromone is a completely new compound in condition that R1 is —CH2CH2CH3, and R2 is —CH2CH3, or that R1 is —C(CH3)3, and R2 is H. All the compounds have obvious inhibitory activity against tyrosinase, and can be used to prepare tyrosinase inhibitors or whitening agents.