Rationale of using hypopigmenting drugs and their clinical application in melasma

Among the pigmentary disorders, melasma is the prototype disorder characterized by hyperpigmentation. Although, conventionally, triple combination creams are used, there is a need for alternatives to hydroquinone as the drug has restrictions on its widespread use. This needs an understanding of the steps involved in the melanogenesis and the drugs that inhibit the key steps. The data on in vitro inhibition need to be then translated into clinical in vivo results, before a rationale compounded fixed drug preparation is marketed that inhibits the major steps in the pigmentation pathway. There is also a need to look for drugs that are superior to hydroquinone, as only then will they have a meaningful clinical utility. For now, a few drugs like deoxyarbutin, ellagic acid, dioic acid, n-butylresorcinol and azelaic acid have such properties in clinical trials, while metformin is a recent addition.     

Antitumor effect of resorcinol derivatives from the roots of Ardisia brevicaulis by inducing apoptosis

Two new resorcinol derivatives 2-methoxy-4-hydroxy-6-(8Z-pentadecenyl)-benzene-1-O-acetate (1) and 2-methoxy-4-hydroxy-6-pentadecyl-benzene-1-O-acetate (2), together with four known compounds 2-methoxy-4-hydroxy-6-tridecyl-benzene-1-O-acetate (ardisiphenol D, 3), 5-(8Z-pentadecenyl)resorcinol (4), 5-pentadecylresorcinol (5), 5-tridecylresorcinol (6), have been isolated from the roots of Ardisia brevicaulis in our previous work. In the present study, the inhibitory effect of 1–6 on the proliferation of human pancreatic PANC-1, human lung A549, human gastrointestinal carcinoma SGC 7901, human breast MCF-7, and human prostate PC-3 cancer cells was evaluated by the methyl thiazolyl tetrazolium method. Compounds 1–6 all showed inhibitory activities against the proliferation of PANC-1, A549, SGC7901, MCF-7, and PC-3 cancer cells. Compound 3, the most active agent and the main constituent with the highest yield, induced apoptosis of PANC-1 cells (the most sensitive cell line among the cell lines screened) via the activation of caspase-3 and caspase-9, up-regulation of the ratio of bax/bcl-2 protein expression.     

Two new resorcinols from Sargassum thunbergii

Two new resorcinols, 1-(5-acetyl-2,4-dihydroxyphenyl)-3-methylbutan-1-one (1) and 1-(5-acetyl-2-hydroxy-4-methoxyphenyl)-3-methylbutan-1-one (2), have been isolated from the brown algae Sargassum thunbergii (Mert.) O'Kuntze. Their structures were elucidated on the basis of spectroscopic methods.     

Induction of apoptosis on human hepatocarcinoma cell lines by an alkyl resorcinol isolated from Lithraea molleoides

INTRODUCTION Hepatocellular carcinoma is the 5th most common cancer in the world and the 4th most common cause of cancer-associated mortality[1]. Surgical resection and local treatment are frequently limited, as a result of metastasis, cirrhosis, and othe…     

双波长分光光度法测定复方薄荷脑洗剂的含量

目的：建立一种同时测定制剂中多组分含量的分光光度法。方法：采用双波长分光光度法,不经分离直接测定复方薄荷脑洗剂中间苯二酚与水杨酸的含量,间苯二酚的测定波长275．35nm,参比波长为321．20nm,水杨酸的测定波长为300．10nm,无需参比波长。结果：间苯二酚的平均回收率为101．08％,RSD为0．96％,相关系数r=0.9995,水杨酸的平均回收率99．92％,RSD为0．35％,相关系数r=0.9999,结论：本法快速,简便,结果准确。     

偏最小二乘法－紫外分光光度法同时快速测定多组分的含量

本文用偏最小二乘－紫外分光光度法同时测定复方水杨酸搽剂中水杨酸、间苯二酚和苯酚的含量。平均回收率分别为：１００．４±０．６％、１０１．５±０．８％和９９．５±１．０％（置信度９５％）。实测３批样品，结果准确、可靠。     

反相高效液相色谱法同时测定复方水杨酸洗剂中水杨酸和间苯二酚的含量

目的　建立测定复方水杨酸洗剂中水杨酸和间苯二酚含量的高效液相色谱法。方法　采用反相C18色谱柱,以乙腈 甲醇 水(10∶5∶85 )为流动相,流速: 1. 0mL·min-1,检测波长为 278nm。结果　水杨酸与间苯二酚的线性范围均为 300 ~900μg·mL-1,水杨酸r=0. 999 6,平均回收率为 100. 24%,RSD为 0. 83%;间苯二酚r=0. 9995,平均回收率为 99. 97%,RSD为 1. 02%.结论　该方法简便准确,可同时测定复方水杨酸洗剂中水杨酸及间苯二酚的含量。