熊果苷类似物的合成、表征及美白活性

目的设计合成一系列熊果苷类似物,并评价其酪氨酸酶抑制活性。方法以邻苯二酚、间苯二酚、对苯二酚为原料,通过一侧酚羟基的苄基保护,与溴乙酰基半乳糖、葡萄糖、木糖、阿拉伯糖进行偶联并脱除保护基,得到11个未见报道的熊果苷类似物。通过~1H-NMR、~(13)C-NMR、HRMS等波谱分析方法对所合成的11个目标化合物进行结构表征。以α-熊果苷为阳性对照,对目标化合物及中间体进行抗酪氨酸酶活性测试。结果与结论目标化合物具有良好的酪氨酸酶抑制活性。其中,化合物p-5a、o-5a、p-4d、m-4d、m-5d的活性与阳性对照物α-熊果苷相当,化合物p-5d的活性优于阳性对照物α-熊果苷。     

氨曲南的合成

目的：以L-苏氨酸为起始原料，经N-Boc保护合成氨曲南。方法：以三．苏氨酸为原料，经酯化、氨解、氨基保护、保护羟基、磺化、环合、脱保护7步反应，制得氨曲南主环，并最终合成氨曲南。结果和结论：目标化合物经核磁共振氢谱确证其化学结构，收率60．4％（以氨曲南主环计）。该法工艺简单，反应效率提高。     

α-熊果苷的研究进展

目的介绍了α-熊果苷最新研究和开发的情况。方法综合最新国内外文献报道，与β-熊果苷在药理作用方面进行了比较，简述目前工业化生产α-熊果苷所采用的方法。结果和结论α-熊果苷作为目前最好的安全高效美白剂，有着广阔的应用前景．应该引起我国化学合成行业的足够关注，参与在化妆品行业的全球性竞争。     

熊果苷的遗传毒性及人体表皮细菌对熊果苷代谢转化作用研究

目的探讨化妆品美白活性成分α-熊果苷、β-熊果苷、脱氧熊果苷的遗传毒性及人体表皮细菌对其代谢转化作用。方法应用Ames试验和哺乳动物细胞染色体畸变试验评价α-熊果苷、β-熊果苷、脱氧熊果苷和氢醌的遗传毒性;从17个健康人的皮肤表面分离细菌并进行菌株鉴定,将分离的菌株分别与α-熊果苷、β-熊果苷和脱氧熊果苷孵育20h后,应用HPLC方法检测α-熊果苷、β-熊果苷和脱氧熊果苷被菌株代谢转化为氢醌的比率。结果与结论 Ames试验分析未发现α-熊果苷、β-熊果苷、脱氧熊果苷和氢醌有致突变性;氢醌浓度为50μmol·L-1时,可引起CHO细胞染色体畸变;未发现α-熊果苷、β-熊果苷和脱氧熊果苷引起CHO细胞染色体畸变。对从17个健康人皮肤分离的36株细菌（来自6个属,14个种）分析发现,有20株菌（来自13个种）可将α-或β-熊果苷代谢转化为氢醌,未发现细菌将脱氧熊果苷代谢转化为氢醌。     

熊果苷的应用及检测研究进展

熊果苷(arbutin)属氢醌苷化合物,有两种差向异构体,即α和β型熊果苷。熊果苷具有抗炎、抑菌、镇咳、祛痰、平喘作用,并具有天然美白活性,在临床应用广泛。含熊果苷的药物常用于治疗气管炎、感染性泌尿系统疾病、皮肤病、过敏及炎症性疾病。熊果苷能有效地抑制皮肤中的生物酪氨酸酶(tyrosinase)活性,阻断黑色素的形成,通过自身与酪氨酶直接结合,加速黑色素的分解与排泄,从而减少皮肤色素沉积,祛除色斑和雀斑,常被作为祛斑药物和美白、美容护肤品的添加物,特别是α-熊果苷因效果突出和安全性高,尤受青睐。近年来,熊果苷因其在药物中的治疗作用和在化妆品中美白、祛斑效果突出和绿色安全而日益受到医疗界及爱美人士的青睐。熊果苷在国内外的应用日趋广阔,在药物和化妆品中的应用和检测有了迅速的发展。本文对熊果苷在药物和化妆品中的应用及检测研究进展做一综述。     

均匀设计法优化复方熊果苷凝胶的基质处方

目的:优化祛斑外用制剂复方熊果苷凝胶的基质处方。方法:以卡波姆-940、甘油+丙二醇、三乙醇胺、氮酮加入量为可变因素,以复方熊果苷凝胶的性状均匀性、润滑性、黏附力、保湿率、pH为考察指标,通过均匀设计试验优化处方。结果:最佳基质处方为:卡波姆-940为0.8%,三乙醇胺为0.8%,甘油+丙二醇为40%,氮酮为1%。结论:复方熊果苷凝胶制备工艺简便、外观细腻均匀、润滑性黏附力好、符合临床应用要求。     

佛波酯磷脂酰－L－丝氨酸（PEPS）中间体的合成工艺改进

目的改进佛波酯磷脂酰-L-丝氨酸（PEPS）的中间体3-苄基-2-（8-叔丁基二苯基硅氧辛酰基）-1-三苯甲基-Sn-甘油（9）和N-叔丁氧羰基-L-丝氨酸二苯甲酯（11）的合成工艺。方法以D-甘露醇为原料，经丙叉基保护、氧化-还原、苄基保护、脱丙叉保护、选择性保护、酯化、羧基还原、硅烷基保护合成化合物9；以L-丝氨酸为原料，经氨基、羧基保护合成化合物11。结果与结论目标化合物的结构经。H-NMR谱确证，改进后的工艺，缩短了合成路线，简化了柱色谱分离、纯化步骤，具有原料易得，操作简便，成本低廉的优点。     

α-熊果苷的研究进展

目的　介绍了α-熊果苷最新研究和开发的情况。方法　综合最新国内外文献报道,与β熊果苷在药理作用方面进行了比较,简述目前工业化生产α- 熊果苷所采用的方法。结果和结论α-熊果苷作为目前最好的安全高效美白剂,有着广阔的应用前景,应该引起我国化学合成行业的足够关注,参与在化妆品行业的全球性竞争。     

相转移催化法合成克林霉素磷酸酯

以克林霉素醇化物为原料，经选择性羟基保护、相转移催化磷酰化、脱保护、精制等步骤合成克林霉素磷酸酯，改进后的工艺操作简单、成本低、产品质量稳定，适合工业化生产。     

降血脂药辛伐他汀的合成工艺改进

摘 要：目的 改进辛伐他汀的合成工艺。方法 以洛伐他汀为起始原料，经水解、内酯环合、羟基保护、酯化、脱保护共5步反应制得辛伐他汀。结果与结论改进了中间体3和6的合成工艺，中间体和终产物的结构均经1H-NMR谱确证，总收率为76.3%。该工艺路线操作简便，适合工业化生产。     

透皮促进剂对肤康祛斑凝胶体外透皮吸收的影响

目的考察透皮促渗剂对肤康祛斑凝胶的主药熊果苷体外经皮渗透的影响。方法对优化后的肤康祛斑凝胶处方,以大鼠离体皮肤作为渗透屏障,用高效液相色谱法测定凝胶中熊果苷经皮透入接收液含量。考察氮酮、氮酮-薄荷油、氮酮-冰片作为促渗剂对熊果苷透皮吸收的影响。结果肤康祛斑凝胶中熊果苷的体外累积渗透率符合Weibull分布,以氮酮-薄荷油作为促渗剂的处方中,熊果苷累积渗透率最高,渗透促进剂的促透效果为:氮酮-薄荷油>氮酮-冰片>氮酮。结论以氮酮-薄荷油作为促渗剂,对熊果苷有较好的促渗作用。     

Role of metabolism by intestinal bacteria in arbutin-induced toxicity in vitro

A possible role of metabolism by intestinal bacteria in arbutin-induced toxicity was investigated in mammalian cell cultures. Following an incubation of arbutin with intestinal bacteria, either Bifidobacterium longum HY81 or Bifidobacterium adolescentis, for 24 h, its aglycone hydroquinone could be produced and detected in the bacterial culture media. The bacterial growth was not affected up to 10 mM arbutin in the culture medium. When the toxicity of bacteria cultured medium with arbutin was tested in the HepG2 cell lines, the medium with arbutin was more toxic than either parent arbutin only or bacteria cultured medium without arbutin, indicating that metabolic activation might be required in arbutin-induced toxicity. In addition, bacteria cultured medium with arbutin could suppress LPS and ConA mitogenicity in splenocyte cultures prepared from normal mice. The results indicate that the present toxicity testing system might be applied for assessing the possible role of metabolism by intestinal bacteria in certain chemical-induced toxicity in mammalian cell cultures.     

Arbutin inhibits TCCSUP human bladder cancer cell proliferation via up-regulation of p21

Arbutin is a glycosylated hydroquinone extracted from the bearberry plant (Arctostaphylos species). In the present study, we determined the effects of arbutin on TCCSUP human bladder carcinoma cell proliferation. Arbutin did not exhibit any cytotoxic effects in TCCSUP cells at concentrations of < 500 microg/ml. To determine the effects of arbutin on cell proliferation, TCCSUP cells were treated with arbutin at various concentrations, and the cell proliferation was measured using the MTT assay. Arbutin significantly decreased TCCSUP cell proliferation in a concentration- and time-dependent manner. Furthermore, cell cycle analysis revealed that arbutin strongly disrupted the cell cycle in a time-dependent manner. Western blot analysis demonstrated that arbutin led to the inactivation of extracellular signal-regulated kinase (ERK), which is known to critically regulate cell proliferation. In addition, arbutin markedly increased the expression of p21WAF1/CIP1 (p21), which is known to be highly involved in cell cycle regulation. Therefore, this study suggests that arbutin inhibits TCCSUP cell proliferation via ERK inactivation and p21 up-regulation.     

Mutagenicity of arbutin in mammalian cells after activation by human intestinal bacteria.

Arbutin (hydroquinone-beta-D-glucopyranoside) is present in various food plants. Its aglycone, hydroquinone, is mutagenic and carcinogenic. We investigated whether hydroquinone may be released under conditions encountered in the human gastrointestinal tract. Arbutin was stable in artificial gastric juice. Fecal slurries from nine human subjects completely converted arbutin (2 mM) into hydroquinone. Four of nine representative human intestinal species investigated, namely Eubacterium ramulus, Enterococcus casseliflavus, Bacteroides distasonis, and Bifidobacterium adolescentis, deglycosylated arbutin at rates of 21.08, 16.62, 8.43 and 3.59 nmol x min(-1) x (mg protein)(-1), respectively. In contrast, homogenates from small intestinal mucosa and cytosolic fractions from colon mucosa deglycosylated arbutin at substantially lower rates: 0.50 and 0.09 nmol x min(-1) x (mg protein)(-1), respectively. Arbutin, unlike hydroquinone, did not induce gene mutations in Chinese hamster V79 cells in the absence of an activating system. However, in the presence of cytosolic fractions from E. ramulus or B. distasonis, arbutin was strongly mutagenic. Cytosolic fraction from Escherichia coli, showing no arbutin glycosidase activity, was not able to activate arbutin in this model system. The release of the proximate mutagen hydroquinone from arbutin by intestinal bacteria in the immediate vicinity of the colon mucosa may pose a potential risk.     

New High-performance Liquid Chromatography-DAD Method for Analytical Determination of Arbutin and Hydroquinone in Rat Plasma

Natural substances present in herbal preparations should be carefully used because they can give toxic or therapeutic effects despite of their amount or the way of administration. The safety of products of vegetable origin must be assessed before commercialisation by monitoring the active ingredients and their metabolites. This study was therefore designed to identify and quantify arbutin and its metabolite hydroquinone, naturally present in Arctostaphylos uva-ursi (L.) Spreng plant in rat plasma, after an acute and subacute administration of aqueous arbutin solution in Wistar rats. For this purpose a reversed-phase high-performance liquid chromatography coupled with photodiode array detection was developed to assess the pharmacokinetic of arbutin and hydroquinone in plasma of female rats treated with aqueous arbutin solutions. The detection (arbutin: 0.0617 µg/ml and hydroquinone 0.0120 µg/ml) and quantification (arbutin: 0.2060 µg/ml and hydroquinone: 0.0400 µg/ml) limits were determined. At the arbutin concentration level of 10.7 µg/ml repeatability was 13.33% and its recovery 93.4±6.93%, while at the hydroquinone concentration level of 10.6 µg/ml repeatability was 11.66% and its recovery 92.9±7.75%. Furthermore the method was fully validated and the obtained data indicate that the new method provides good performances.     

梨树叶中有效成分熊果苷的确证及HPLC检测

目的 确证梨树叶中含有熊果苷,并建立高效液相色谱法测定梨树叶中熊果苷的含量。方法 将充分粉碎的梨树叶样品用甲醇提取,蒸去甲醇后用ENVI^TM-18固相萃取柱净化,采用在线获取的紫外光谱及扫描质谱对熊果苷进行确证。高效液相色谱分析时用Inertsil ODS-3色谱柱分离,甲醇-水（1∶9）洗脱,282 nm检测。结果 梨树叶样品中目标物的紫外吸收光谱及子离子扫描质谱图与熊果苷标准品相同。高效液相色谱法定量分析时线性关系良好,熊果苷的回收率〉93%,RSD〈2.1%。结论 梨树叶中含有熊果苷有效成分,高效液相色谱法检测梨树叶中熊果苷的含量简便、快速、准确。     

Densitometric determination of arbutin in cowberry leaves (Vaccinium vitis idaeae)

Densitometry was used for quantitative determination of arbutin (Vaccinium vitis idaeae) in leaves of cowberry collected from region of Suwalszczyzna, Poland. Arbutin was extracted using methanol. Chromatography was performed on glass TLC plates with layers of silica gel. The quantitative densitometric analysis was performed using internal standard solution method. On the base of densitometric analysis it was shown that the band characteristic for absorption maximum of arbutin is placed at lambda(max) = 285 nm. The second absorption band is at lambda = 225 nm. It was stated that contents of arbutin are ca. 35 mg and 47 mg in 1 g of herbs, in cowberry leaves coming from collections in 2005 and 2006 year, respectively. The presented method is accurate, selective, and precise, and can be used for routine quality control analysis and quantitative determination of arbutin in cowberry leaves.     

Aloesin and arbutin inhibit tyrosinase activity in a synergistic manner via a different action mechanism

In this study, we present evidence that cotreatment of aloesin and arbutin inhibits tyrosinase activity in a synergistic manner by acting through a different action mechanism. Aloesin or arbutin similarly inhibited enzyme activity of human- and mushroom-tyrosinases with an IC50 value of 0.1 or 0.04 mM, respectively. Lineweaver-Burk plots of the enzyme kinetics data showed that aloesin inhibited tyrosinase activity noncompetitively with a Ki value of 5.3 mM, whereas arbutin did it competitively (Maeda, 1996). We then examined whether cotreatment of these agents inhibits the tyrosinase activity in a synergistic manner. The results showed that 0.01 mM aloesin in the presence of 0.03 mM arbutin inhibited activity of mushroom by 80% of the control value and the reverse was also true. The inhibitory effects were calculated to be synergistic according to the Bürgi method. Taken together, we suggest that aloesin along with arbutin inhibits in synergy melanin production by combined mechanisms of noncompetitive and competitive inhibitions of tyrosinase activity.     

Inhibitory effects of arbutin on melanin biosynthesis of α-melanocyte stimulating hormone-induced hyperpigmentation in cultured brownish guinea pig skin tissues

Arbutin has been used as a whitening agent in cosmetic products. Melanin, the major pigment that gives color to skin, may be over-produced with sun exposure or in conditions such as melasma or hyperpigmentary diseases. Tyrosinase is a key enzyme that catalyzes melanin synthesis in melanocytes; therefore, inhibitors of the tyrosinase enzyme could be used for cosmetic skin whitening. A recent study has reported that arbutin decreases melanin biosynthesis through the inhibition of tyrosinase activity. However, this inhibitory mechanism of arbutin was not sufficiently demonstrated in skin tissue models. We found that arbutin both inhibits melanin production in B16 cells induced with α-MSH and decreases tyrosinase activity in a cell-free system. Furthermore, the hyperpigmentation effects of α-MSH were abrogated by the addition of arbutin to brownish guinea pig and human skin tissues. These results suggest that arbutin may be a useful agent for skin whitening.