Finite dose diffusion studies: I. Characterizing cuticular penetration in a model system using NAA and isolated tomato fruit cuticles.
Finite dose diffusion studies: I. Characterizing cuticular penetration in a model system using NAA and isolated tomato fruit cuticles.
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有限剂量扩散研究： I. 使用 NAA 和分离的番茄果实角质层表征模型系统中的角质层渗透。
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
M. J. Bukovac
中科院分区：
文献类型：
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作者：
M. Knoche;P. Petracek;M. J. Bukovac
采用有限剂量扩散系统研究 2-(1-萘基)[1−14C]乙酸 (NAA) 从模拟喷雾液滴通过酶法分离的番茄果实角质层 (Lycopersicon esculentum Mill cv Pik Red) 的角质层渗透。将分离的角质层安装在扩散半电池上，细胞壁表面面向20mM柠檬酸接收溶液（pH 3.2，体积2.9ml，用去离子水制备）。将含有 100μM NAA 的 20mM 柠檬酸缓冲液（pH 3.2）的 5μl 供体液滴施加到外表面。通过对接收溶液重复取样来监测渗透性。 NAA 渗透的特点是 (1) 约 2.3 h 的初始滞后阶段，(2) 几乎恒定的最大渗透率阶段，平均为所应用 NAA h−1 的 6.3%（相当于 0.032nmol h−1），以及 (3) 在 81.2% 所应用 NAA（相当于 0.406nmol）处接近渐近线的平台期。 120小时。施用后 1 小时内，目视检查发现液滴已干燥。液滴干燥后，7.0% 的 NAA 立即被吸附到角质层，但只有 0.5% 渗透到接收溶液中，表明渗透几乎完全来自表面干燥的沉积物。 120小时时，所施加的NAA的5.2%与沉积物相关，4.3%与角质层相关。最大渗透率的分布呈对数正态分布，但 120 小时的渗透率遵循正态分布。角质层厚度（估计为 5-25μm）对 NAA 渗透没有显着影响。辣椒果实、柑橘和榕树叶角质层的最大渗透率分别是番茄果实角质层的 4.9、2.6 和 0.1 倍。 120 小时时，辣椒、柑橘和榕树角质层的平均渗透率分别为 85.5%、79.5% 和 34.7%。提取角质层外蜡和嵌入蜡可使 NAA 通过番茄果实角质层的渗透率提高三倍以上，但对 120 小时时的渗透率几乎没有影响（角质层膜与脱蜡角质层膜的渗透率分别为 71.0% 和 87.7%）。发现最大渗透率和总渗透率是描述渗透时间过程的有用参数。
© 2000 中国化学工业学会
A finite dose diffusion system was employed to study cuticular penetration of 2-(1-naphthyl) [1−14C]acetic acid (NAA) from simulated spray droplets through enzymatically isolated tomato fruit cuticles (Lycopersicon esculentum Mill cv Pik Red). Isolated cuticles were mounted on diffusion half-cells with the cell wall surfaces facing a 20 mM citric acid receiver solution (pH 3.2, volume 2.9 ml, prepared with deionized water). A 5-µl donor droplet containing NAA at 100 µM in 20 mM citric acid buffer (pH 3.2) was applied to the outer surface. Penetration was monitored by repeated sampling of the receiver solution. NAA penetration was characterized by (1) an initial lag phase of about 2.3 h, (2) a phase of nearly constant maximum rate of penetration averaging 6.3% of applied NAA h−1 (equivalent to 0.032 nmol h−1) and (3) a plateau phase approaching an asymptote at 81.2% of applied NAA (equivalent to 0.406 nmol) at 120 h. Within 1 h after application droplets appeared dry on visual inspection. Immediately after droplet drying, 7.0% of the applied NAA was sorbed to the cuticle, but only 0.5% penetrated into the receiver solution, indicating that penetration occurred almost exclusively from the apparently dry deposit. At 120 h, 5.2% of the NAA applied was associated with the deposit and 4.3% with the cuticle. The distribution of maximum rates of penetration was log-normal, but penetration at 120 h followed a normal distribution. Cuticle thickness (estimated 5–25 µm) had no significant effect on NAA penetration. Maximum rates of penetration through pepper fruit and citrus and ficus leaf cuticles were 4.9-, 2.6- and 0.1-times that through tomato fruit cuticles. At 120 h, penetration averaged 85.5, 79.5 and 34.7% for pepper, citrus and ficus cuticles, respectively. Extracting epicuticular and embedded waxes increased NAA penetration rates through tomato fruit cuticle more than three-fold, but had little effect on penetration at 120 h (71.0 vs 87.7% for cuticular vs dewaxed cuticular membranes). The maximum penetration rate and total penetration were found to be useful parameters in describing the penetration time-course.
© 2000 Society of Chemical Industry