高效液相色谱法测定防晒化妆品中的二乙氨基羟苯甲酰基苯甲酸己酯及甲酚曲唑三硅氧烷

建立了高效液相色谱法同时测定防晒类化妆品中二乙氨基羟苯甲酰基苯甲酸己酯和甲酚曲唑三硅氧烷的方法。准确称取一定量混匀样品,经流动相(V质量分数0.1%的甲酸/水︰V甲醇︰V四氢呋喃=2︰6︰2)提取过滤后,用Welch Xtimate®C18柱(250 mm×4.6 mm×5μm)分离,再用此流动相梯度洗脱,检测波长为305 nm和355 nm。两种防晒剂在相应浓度区间线性良好(r>0.999),回收率为85%~107%,相对标准偏差<3%。该方法操作简便、结果准确、灵敏度高,适用于化妆品中两种防晒剂含量的测定。

防晒类化妆品中二乙氨基羟苯甲酰基苯甲酸己酯的高效液相色谱测定法

目的建立防晒类化妆品中二乙氨基羟苯甲酰基苯甲酸己酯的高效液相色谱(HPLC)测定法。方法样品用甲醇超声提取,以甲醇-水(体积比为88∶12)为流动相,采用Inersil C18色谱柱(250 mm×4.6 mm,5μm),流量为1 ml/min,检测波长为356 nm。结果在1～100 mg/L的线性范围内,所得到的含不同空白基质(防晒霜、防晒乳和防晒露)的二乙氨基羟苯甲酰基苯甲酸己酯的回归方程均呈良好的线性关系r,>0.999。该方法的检出限0.05 mg/L,回收率为97.2%～101.5%,RSD为0.68%～2.61%。结论该方法的样品前处理操作简单,分离速度快,回收率高,重现性好,具有较高的准确度和精密度,适用于化妆品中二乙氨基羟苯甲酰基苯甲酸己酯的分析测定。

高效液相色谱法同时测定防晒类化妆品中二苯酮-2等3种防晒剂组分的含量

建立一种高效液相色谱法同时测定防晒类化妆品中3种防晒剂组分(二苯酮-2、二乙氨羟苯甲酰基苯甲酸己酯和二乙基己基丁酰胺基三嗪酮)的含量。色谱柱为Inertsil C_(18)(4.6×250 mm,5μm),流动相为甲醇-水,梯度洗脱,流速为1.0 mL/min,检测波长二苯酮-2为335 nm、二乙氨羟苯甲酰基苯甲酸己酯为356 nm、二乙基己基丁酰胺基三嗪酮为307 nm。3种新型防晒剂组分在40 min内完全分离,线性范围0.96~66.5 mg/L(r=0.999 8~0.999 9),检测限为0.01~0.04 mg/L,定量限为0.03~0.11 mg/L,回收率为98%~107%。该方法简便、快速、准确、可靠,适合防晒类化妆品中防晒剂组分的含量测定。

Chemical Constituents from Piper wallichii

Aim To investigate the chemical constituents of Piper wallichii. Methods Five compounds were isolated by silica gel column chromatography and Sephadex LH-20 gel column chromatography, and the structures of compounds were identified by spectral analysis. Result Five compounds were identified as piperlonguminine （trans, trans） （1）, 4-hydroxy-3,5-dimethoxy-benzoic acid （2）, galgravin （3）, β-sitosterol （4）, and daucosterol （5）. Conclusion Five compounds were isolated from Piper wallichii for the first time, and compounds 1 -3 were isolated from this genus far the first time.

First Asymmetric Synthesis of (-)Methyl 2, 2-dimethyl-3-hydroxychromanyl-6-formate

Aim To synthesize naturally occurring (-) methyl2,2-dimethyl-3-hydroxychromanyl-6-formate. Methods Sharpless' asymmetric dihydroxylation wasemployed to construct the 3-hydroxychroman. Results First asymmetric synthesis of (-) methyl 2,2-dimethyl-3-hydroxychromanyl-6-formate (1) was accomplished starting from methyl 4-hydroxy-benzoate(2), and the absolute configuration was established. Conclusion A useful method for constructingchiral 3-hydroxychroman by employing Sharpless' asymmetric dihydroxylation is achieved.

鲜艳的水果皮不宜食用

凡是外皮鲜艳的水果都应该削皮后食用，如苹果、梨因为它们的果皮含有丰富的“炎黄酮”。这种化学物质进入人体，经肠遵细菌分解成为二羟苯甲酸等．对甲状腺有很强的抑制功能．到一定程度会引起甲状腺浮肿。

三种防晒剂的测定及在化妆品中的应用

建立了高效液相色谱法同时测定化妆品中二苯酮-3、二乙氨羟苯甲酰基苯甲酸己酯和丁基甲氧基二苯甲酰基甲烷的方法。采用ZORBAX SB-Aq液相色谱柱,甲醇-水(体积比90︰10)作为流动相,检测波长为356 nm。结果表明:在此条件下,这3种防晒剂能够有良好的分离效果,在10~100 mg/kg范围内线性良好,相关系数均大于0.999。该方法的检出限为2 mg/kg,回收率为93%~100.5%,相对标准偏差为0.7%~1.1%。

Extraction and PTP1B inhibitory activity of bromophenols from the marine red alga Symphyocladia latiuscula

Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this species collected from the Weihai coastline of Shandong Province remains blank. Therefore, we characterized the chemical constituents of individuals of this species collected from the region. Eight bromophenols were isolated and identified. Using detailed spectroscopic techniques and comparisons with published data, these compounds were identified as 2,3-dibromo-4,5-dihydroxybenzyl methyl ether (1), 3,5-dibromo-4-hydroxybenzoic acid (2), 2,3,6-tribromo-4,5-dihydroxymethylbenzene (3), 2,3,6-tribromo-4,5-dihydroxybenzaldehyde (4), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (5), bis(2,3,6-tribromo-4,5-dihydroxyphenyl)methane (6), 1,2-bis(2,3,6-tribromo-4,5-dihydroxyphenyl)-ethane (7), and 1-(2,3,6-tribromo-4,5-dihydroxybenzyl)-pyrrolidin-2-one (8). Among these compounds, 1 and 2 were isolated for the first time from S. latiuscula. Each compound was evaluated on the ability to inhibit protein tyrosine phosphatase 1B (PTP1B), which is a potential therapeutic target in the treatment of type 2 diabetes. Bromophenols 5, 6, and 7 showed strong activities with IC50 values of 3.9, 4.3, and 3.5 μmol/L, respectively. This study provides further evidence that bromophenols are predominant among the chemical constituents of Symphyocladia, and that some of these compounds may be candidates for the development of anti-diabetes drugs.

脊髓损伤后羟自由基的改变

以Ａｌｌｅｎ法造成脊髓损伤模型，对照组仅做椎板切除。伤后静脉注射水杨酸钠１００ｍｇ／ｋｇ体重。于４小时后采用高效液相色谱加电化学检测技术测定脊髓组织二羟苯甲酸含量。结果表明，损伤组２，３－与２，５－二羟苯甲酸含量高于对照组，其中以２，５－二羟苯甲酸最为明显（Ｐ＜０．００１），从而提示脊髓损伤后有大量羟自由基形成，进一步证实自由基确实参与了脊髓损伤的病理过程。

保健小常识

科学研究表明,水果外皮颜色鲜艳的(如红、黄、蓝、绿),均应去皮后再吃。因为这种植物色素含类黄酮,这是一种化学物质,进入体内,经细菌分解,会转化为二羟苯甲酸和阿魏酸,具有很强的抑制甲状腺功能的作用,从而引起甲状腺肿。所以凡是果皮颜色鲜艳的水果应去皮后再吃。

饭后不得做的9件事

一,不要立刻吃水果。水果中含有类黄铜化合物,摄入后经肠道细菌作用转化为二羟苯甲酸,而摄入的蔬菜中含有硫氰酸盐,在这两种化学物质作用下,干扰甲状腺功能,可导致非碘性甲状腺肿。

文摘

世界狗之最最重的狗目前公认的世界上最重的狗是英国伦敦北部的一条叫“佐巴”的大狗,它有7岁,体重150公斤,身长2.6米。“佐巴”的胃口大得惊人,每天要吃5公斤牛肉,外加饼干和鳕鱼油等,

Multi-component hydrogen-bonding salts formed between imidazole and aromatic acids:Synthons cooperation and crystal structures

Imidazole base was crystallized with different aromatic carboxylic acids 2,4-dihydroxybenzoic acid, 5-chlorosalicylic acid, and 1,8-naphthalic acid, affording three new binary molecular organic salts of [(C 3 H 5 N 2 + )·(C 7 H 5 O 4 )] (1), [(C 3 H 5 N 2 + )·(C 7 H 4 O 3 Cl )] C 7 H 5 O 3 Cl (2), and [(C 3 H 5 N 2 + ) (C 12 H 7 O 4 )] (3). Proton transfer occurs from the COOH of carboxylic acid to nitrogen of imidazole in all complexes (1-3), leading to the hydrogen bond N-H…O in all structures. To our knowledge, the recognition pattern between the carboxylic acid group and imidazole (acid-imidazole synthon) is less well-studied so far. The cooperation among COOH, COO and imidazolium cation functional groups for the observed hydrogen bond synthons is examined in the three structures. Generally, the strong N-H…O and O-H…O hydrogen bonds define supramolecular architecture and connectivity within chains, while weaker C-H…O hydrogen bonds play the dominant role in controlling the interactions between layers in these novel organic salts. Thermal stability of these compounds has been investigated by thermogravimetric analysis (TGA) of mass loss.

Co-crystallization of glycine anhydride with the hydroxybenzoic acids: Controlled formation of dimers via synthons cooperation and structural characterization

The results of crystallographic analyses on 1：1 and 1：4 well-defined co-crystals formed between glycine anhydride and each of 4-hydroxybenzoic acid and 3,5-dihydroxybenzoic acid are described. Neutral molecules are connected via heteromeric O-H.-.O and N-H…O contacts leading to different packing arrangements of supramolecular chains. On the basis of the molec- ular structures of glycine anhydride and carboxylic acid guests, the hydrogen bonds are arranged to give centrosymmetric synthons V and VII which are noteworthy for their robustness. Hydrogen-bond interactions between glycine anhydride and aromatic acid provide sufficient driving force to direct molecular recognition and crystal packing. Utilization of the orientation of functional groups of the building blocks, the acidity, and weak interactions provides a route for the creation of novel supra- molecular architectures in the crystal lattice. Both two co-crystals contain the expected hydrogen-bonded motifs, and there has been no proton transfer from either of the two carboxylic acids to the aza compound moiety. This demonstrates that glycine anhydride is very capable of affecting the construction of binary co-crystals in a predictable and rationale manner. It is noted that synthons Ⅷ and IX are fairly large, but the real challenge in crystal engineering is to find a big enough synthon that occurs often enough. Thermal stability of these compounds has been investigated by thermogravimetric analysis （TGA） of mass loss.

Hydrogen-bonding directed cocrystallization of flexible piperazine with hydroxybenzoic acid derivatives:Structural diversity and synthon prediction

Four hydroxybenzoic acid building blocks, m-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxyterephthalic acid, and 5-hydroxyisophthalic acid, have been synthesized as robust cocrystallizing agents and employed in reactions with piperazine, including [（C4H12N2 2＋）.（C7H5O3-）2] （l）, [（CaH12N2 2＋）.（C7H5O4-）2] （2）, [（C4H12N2 2＋）.（C8H5O6 2- ）] （3）, and [（C4H12N2 2＋）1/2. （C8H5O5）] . 2H2O （4）. Hydrogen-bonded directed assemblies of four salts were validated by single-crystal X-ray diffraction analysis. In compounds 1-4, hydroxybenzoic acids are all deprotonated and piperazine molecules are all protonated to form piperazine dications and keep the chair conformation. Thermal stability of these compounds has been investigated.