天然植物紫外线防护效果研究

为探索天然植物在防晒化妆品中的应用,选择天然植物提取物根皮素、白藜芦醇和熊果苷,研究其安全性及紫外线防护效果。采用紫外分光光度法测定天然植物提取物的紫外吸收特征,同时将其复配成防晒产品。在采用封闭式斑贴试验评价防晒产品安全性的基础上,应用人体试验测定产品防晒指数(SPF值)和长波紫外线防护指数(PFA值)。结果发现,3种植物提取物表现出不同的紫外吸收能力,中波紫外线(UVB)波段吸收效果优于长波紫外线(UVA)波段,且白藜芦醇的紫外吸收效果相对最好;人体斑贴试验证明3种天然植物提取物均具有良好的皮肤适应性;防晒效果人体试验显示白藜芦醇和根皮素令SPF值有较为明显的提高。研究表明,部分天然植物提取物表现出良好的紫外线防护效果,且与传统的化学和物理防晒剂相比,具有皮肤刺激性小、光化学稳定、安全可靠等优点,具有广阔的市场前景。     

含受阻胺结构的苯并三唑光稳定性和热稳定性研究

测试了4种2-[2’-羟基-3’-叔丁基-5’-（3-丙酸-4-哌啶酯基）苯基]-2H-苯并三唑结构类光稳定剂紫外吸收光谱、光稳定性及热稳定性。4种化合物在270～400nm均有较强的吸收峰,与引入受阻胺结构前苯并三唑光稳定剂相比．紫外吸收波长和摩尔消光系数不变。4种化合物的光稳定性和热稳定性明显高于引入受阻胺结构前的苯并三唑光稳定剂。光老化12h后,4种化合物仅分解3．2％～6．9％,引入受阻胺结构前苯并三唑则分解35．0％～36．3％。热稳定性测试表明。4种化合物失重1％时的温度为264～272℃．而引入受阻胺结构前苯并三唑失重1％时的温度分别为227℃和235℃。该类化合物分子内同时具有紫外吸收剂和自由基捕获剂两种功能,为高效光稳定剂。     

具有紫外线防护性能的植物提取物研究

研究了四种植物提取物的不同浓度对配方SPF值、PFA值的影响,并详细分析了UVB吸收率与SPF值的关系;分别研究了植物提取物与物理防晒剂、化学防晒剂、铁红、铁黄和铁黑的复配,结果表明:植物提取物与二氧化钛复配,具有针对SPF、PFA值的协同增效作用,但水溶性黄芩苷、杜仲绿原酸与氧化锌复配均出现颜色异常;植物提取物与化学防晒剂均有针对SPF、PFA值的协同增效作用,其中杜仲绿原酸的增效效果最为明显;植物提取物与铁红、铁黄、铁黑的复配表明:铁红、铁黄、铁黑均未对提取物的紫外吸收产生掩蔽作用,但水溶性黄芩苷与铁黑复配出现颜色异常,不可用于彩妆。     

芒果叶提取物广谱防晒性能研究

基于树叶依靠诱导体内合成紫外吸收物质来抵御紫外伤害的生理特性,以树叶为原料提取紫外吸收物,比较不同树叶提取物的紫外吸收情况,结果发现:芒果叶提取物在280~400 nm的防晒区域紫外吸收能力强,强吸收覆盖波段宽,可实现广谱防晒。芒果叶质量浓度4倍于3种化学防晒剂时,其提取物紫外吸收强度高于化学防晒剂,且可在pH=3~7、强太阳光照4 h、80℃、室内存放1年保持稳定,产品化前景好。     

不同溶剂对石榴皮染料提取效果及染色性能的影响

采用不同浓度乙醇和不同pH水两种溶剂从干燥石榴皮粉末中提取石榴皮染料,并分析、比较了提取液的吸光度及颜色、总多酚、三种主要多酚(安石榴甙、鞣花酸、没食子酸)组分含量及其对毛织物的染色效果。结果表明,使用不同浓度(0～80%)乙醇溶液提取石榴皮粉末时,40%乙醇提取效果好,提取液颜色最深,提取物中安石榴甙含量最高,达到410.66 mg/g,且提取物得率高,为47.95%;使用不同pH(pH 3～9)水提取时,pH=5时提取物中安石榴甙含量最高,达到499.15 mg/g,且提取物得率为42.30%。与40%乙醇提取相比,pH=5水从同质量石榴皮粉末中得到的提取液直接染色后的毛织物K/S值大。     

黄岑和菊花复合防晒剂的性能研究

运用紫外可见分光光度仪,以紫外吸收值为指标,测定黄岑和菊花复合防晒剂的防晒性能。结果表明,其具有高效、广谱的防晒效果,稳定性好。     

三种香料植物提取物和精油不可用于化妆品

在欧盟委员会消费品科学委员会(SCCP)第4次例会上,doc.N°Sccp/0869/05中指出万寿菊(Tagetes erecta)、小万寿菊(Tagetes minuta)和孔雀草(Tagetes patula)的提取物和精油(仅就光毒性而言),上述三种香料植物的提取物和精油因有光毒性,SCCP认为不应在化妆品中使用。三种香料植物     

不同溶剂对石榴皮染料提取效果及染色性能的影响

采用不同浓度乙醇和不同pH水两种溶剂从干燥石榴皮粉末中提取石榴皮染料,并分析、比较了提取液的吸光度及颜色、总多酚、三种主要多酚(安石榴甙、鞣花酸、没食子酸)组分含量及其对毛织物的染色效果。结果表明,使用不同浓度(0～80%)乙醇溶液提取石榴皮粉末时,40%乙醇提取效果好,提取液颜色最深,提取物中安石榴甙含量最高,达到410.66 mg/g,且提取物得率高,为47.95%;使用不同pH(pH 3～9)水提取时,pH=5时提取物中安石榴甙含量最高,达到499.15 mg/g,且提取物得率为42.30%。与40%乙醇提取相比,pH=5水从同质量石榴皮粉末中得到的提取液直接染色后的毛织物K/S值大。     

紫外光谱法初步评价11种中药提取物的防晒效果

分别采用体积分数50%乙醇提取了11种中药,并利用紫外光谱法对11种中药提取物的紫外吸收进行了研究,初步评价了它们的防晒效果。结果表明,8种中药提取物对紫外线有一定吸收,为今后开发新型天然植物防晒剂提供了参考。     

HPLC法测定牙膏中银杏叶提取物总黄酮苷的含量

以槲皮素、山奈素和异鼠李素为指标,建立HPLC法测定牙膏中银杏叶提取物总黄酮苷的含量。采用Agilent ZORBAX Eclipse XDB-C18色谱柱（Analytical 4．6×250mm 5-Micron）;流动相为甲醇-0．4％磷酸（55／45,V/V）;流速为1．0mL／min;检测波长为360nm;柱温为40℃;进样量为20μL。结果表明,槲皮素、山奈素和异鼠李素浓度分别在2．1～21．0、1．8～18．0和0．42～4．2μg／mL范围内呈良好的线性关系,相关系数分别为：0．9999、0．9999和0．9998;槲皮素、山奈素和异鼠李素回收率分别为：97．7％、98．3％和97．6％。该方法简单、灵敏、准确,可用于牙膏中银杏叶提取物总黄酮苷含量的测定。     

Phototoxicity ofCitrus jambhiri to fungi under enhanced UV-B radiation: Role of furanocoumarins

Extracts ofCitrus jambhiri foliage exposed to and shielded from UV-B radiation were assayed for phytochemical changes and phototoxicity against four fungal pathogens, two of which (Fusarium solani andF. oxysporum) are causative agents of root rots and two of which (Penicillium italicum andP. digitatum) are associated with fruit rots. Conidial pigment mutants of these four fungal species were assayed to determine whether pigments play a role in protecting fungi against plant photosensitizers. Exposure to 10.2 kJ/ day UV-B radiation for 95 days significantly reduced phototoxicity of leaf extracts to fungi. Although furanocoumarin levels were reduced by UV-B, analysis of covariance revealed that variation in phototoxicity of the extracts cannot be attributed entirely to variation in furanocoumarin content; thus, the possibility exists that nonfuranocoumarin phototoxic constituents, as yet unidentified, respond to UV-B exposure and contribute to overall phototoxic defense ofC. jambhiri against pathogens. Root rot fungi were substantially more sensitive to furanocoumarin phototoxicity than were fruit rot fungi, a pattern consistent with the amount of light exposure normally experienced by these fungi when associated with phototoxic plants. Although pigmented strains of all four species displayed greater resistance to phototoxicity of pure furanocoumarins, no strain differences were detected in assays of foliar extracts; this finding also suggests that nonfuranocoumarin constituents may be involved in the phototoxic defense ofC. jambhiri against pathogens.Deceased.     

Influence of Exposure Conditions on the Bioavailability of Fluoranthene to Daphnia Magna (Cladocera)

A study of the bioavailability of fluoranthene to Daphnia magna (Cladocera) was carried out. Acute toxicity of fluoranthene to Daphnia magna was assessed in various conditions: co-solvent, darkness, classical laboratory lighting, UV exposure, presence or absence of microalgae. Bioaccumulation of fluoranthene in daphnids was also determined. In the dark, the toxicity of fluoranthene was low. Following a 2-h exposure under UV light (254 nm), toxicity increased to a great extent. Under fluorescent light, phototoxicity was also observed. The bioaccumulation of fluoranthene in the dark was maximal after 24 h exposure and related to the aqueous fluoranthene content. No differences were found between both co-solvents. In the presence of microalgae, fluoranthene was far less toxic, whereas bioaccumulation was unchanged. Adsorption of fluoranthene on algae could not explain this lower toxicity which might be due to either absorption of light by algae or a protective effect of algal carotenoid pigments against phototoxicity.     

呋喃香豆素光化学毒性及其脱敏柑橘精油的研制

调查了柑橘类精油中普遍存在的呋喃香豆素类物质的种类、化学结构与分布,尤其是该类化合物对皮肤的光化学毒性作用。采用UV技术对市售芳香疗法用橙油、柠檬油、葡萄柚精油与佛手柑精油等四种柑橘类精油进行了光敏化合物呋喃香豆素含量测定,并使用液-液萃取分离技术实现了精油脱呋喃香豆素类生产性试验,开发研制了四种脱敏精油。这些脱敏精油在芳香疗法使用剂量下,其呋喃香豆素类化合物的含量控制在20ppm以下,保证使用的安全与可靠。     

基于多重乳化体技术制备中草药防晒霜

采用乙醇提取罗勒等7种中草药,将制备的各单一中草药提取液等质量混合,制得中草药提取液组合物。通过紫外分光光度法对其紫外线吸收率进行测定,结果表明其具有较佳紫外线吸收效果。分别采用4种脱色剂活性炭、高锰酸钾、过氧化氢和草酸对其进行脱色研究,结果表明,经草酸脱色后的中草药提取液组合物颜色较浅,且仍保持较好的紫外线吸收效果。基于多重乳化体技术,将制备的中草药提取液组合物添加于W/O/W型多重乳化体的最内相中,制备得到中草药防晒霜,并与单重乳化体中草药防晒霜进行比较。测试评价结果表明,多重乳化体中草药防晒霜具有较好的温和性和稳定性,当中草药提取液组合物添加量为15.0%时,SPF和PFA值分别为20.3和5.3。     

不同颜色体系的UV丝印油墨中光引发体系的选择

使用紫外-可见分光光度计测得了黄、蓝、橙、紫4种颜料的紫外吸收图谱;在模型化的丝印油墨配方中改变光引发剂的种类,运用指压法和指抠法研究了多种光引发剂对含有这4种颜料的UV油墨的引发速度的影响。结果表明不同颜色的颜料对紫外光的吸收区域和吸收强度是不同的。对于黄色油墨,907的引发效果最佳;对于蓝色油墨,907+ITX+EDAB和910+ITX+EDAB都具有很高的引发速度;而对于橙色油墨和紫色油墨,907+ITX+EDAB则是速度最高的引发剂组合。     

Furanocoumarin content and phototoxicity of rough lemon (Citrus jambhiri) foliage exposed to enhanced ultraviolet-B (UVB) irradiation

Rooted cuttings ofC. jambhiri were grown under enhanced levels of UVB radiation for 95 days. Bacterial phototoxicity and furanocoumarin content were determined in extracts made from various tissues from the aboveground biomass. Young, newly expanded leaves contained significantly higher concentrations of furanocoumarins than older leaves and stems. Additionally, the proportional concentration of psoralen was higher in young leaves than in old leaves. While treatment with UVB did not result in a change in the overall level of furanocoumarins, it did cause an increase in the ratio of psoralen to bergapten. Bacterial phototoxicity paralleled the distribution of furanocoumarin content among tissue types; analysis of covariance suggested that the phototoxic properties of the extracts could be accounted for on the basis of furanocoumarin content alone.     

Radiative Ignition of Pyrotechnics: Effect of Wavelength on Ignition Threshold

Using a broadband Xenon lamp and a high power laser diode, the ignition of several pyrotechnic compositions was evaluated using ultraviolet(UV), visible and infrared(IR) radiation. At irradiance levels of 4.9 W/cm² none of the compositions were ignited using UV radiation but SR112, B/Fe₂O₃ and gunpowder showed reactions to visible radiation at irradiance levels as low as 8.1 W/cm². Most of the compositions were ignited with IR radiation but Mg/NaNO₃ and SR 112 could not be ignited at irradiance levels of up to 300 W/cm². It is proposed that the difference in the response of the compositions was not directly related to the radiation absorption characteristics of the compositions; but was dependant on many physical, chemical and optical characteristics of the pyrotechnic powders. Increasing the irradiance reduces the time to ignition for most compositions.     

Toxic Effects of Lemon Peel Constituents on Ceratitis capitata

A series of experiments were conducted to evaluate the toxicity of lemon peel extracts incorporated into mediterranean fruit fly Ceratitis capitata diet. Extracts were obtained with different solvents: diethyl ether, ethyl acetate, and methanol. All three extracts were toxic to some extent; the diethyl ether extract was selected for further studies. Ether extracts of lemon peel were prepared weekly over a 2-month period, from fruits collected on the 1st d of the bioassay. Weekly GC-MS and UV analyses of the extracts demonstrated that the concentration of citral and coumarins decreased in the peel after harvest. We conducted a series of bioassays to evaluate the toxicity of the ether extract, and mixtures of this extract with citral, 5,7-dimethoxycoumarin. and linalool incorporated to C. capitata larvae's natural diet (lemon slices endocarp) at a concentration of 250 microg/g of diet. Significant larvicidal activity can be obtained from a fresh lemon peel extract; however, when the extract was obtained from stored lemons, toxicity decreased. Addition of small amounts of citral or 5,7-dimethoxycoumarin, and linalool to the stored lemon peel extract would bring back the toxicity to the rates of fresh lemons extracts. Finally, female adults of C. capitata fed on diets containing additional amounts of ether extract, 5,7-dimethoxycoumarin, and linalool, were exposed to different photoperiods to test for phototoxicity. The treatment was toxic and affected the oviposition capacity of females depending on photoperiod.