玄参对照提取物的PULCON法定值研究和其在中药复方增液汤中的应用

目的采用氢核磁脉冲宽度定量法(Pulse length based concentration determination,PULCON)对玄参对照提取物中的哈巴苷、安格洛苷C和哈巴俄苷进行定性及定值研究,探讨玄参对照提取物代替相应对照品在提升玄参复方制剂质量控制水平的可行性。方法采用Bruker Avance III HD 700超导核磁共振波谱仪,以DMSO-d6为溶剂,苯甲酸为外标物,利用PULCON法比较苯甲酸定量峰(δ_(H)7.94)的峰面积和不同批次玄参对照提取物中3种化学成分的不同定量峰(哈巴苷δ_(H)6.24、安格洛苷Cδ_(H)7.08和哈巴俄苷δ_(H)5.97)的峰面积,测定不同批次中3种成分的含量,并采用配对t检验将测定结果与高效液相色谱法(High performance liquid chromatography,HPLC)的定值结果进行比对。分别以已知含量的玄参对照提取物和3个相应对照品为对照,建立增液汤的HPLC含量测定方法,采用配对t检验对2种方法所得结果进行比较。结果采用PULCON法测得3种成分的含量与HPLC法的定值结果基本一致,以玄参对照提取物为对照,3种成分的线性关系相关系数均大于0.9997,平均回收率为99.36%~102.31%。t检验结果显示,2种方法测定的哈巴苷、安格洛苷C、哈巴俄苷含量P值分别为0.279、0.105、0.623,均大于0.05,表明2种含量测定方法差异无统计学意义。结论PULCON法可在无对照品且无需分离的条件下,直接、快速、准确地分析玄参对照提取物成分的物质组成和含量,并将已标定准确含量的玄参对照提取物用于玄参复方制剂的质量控制,为中药对照提取物在中药质量研究中的应用提供了科学依据。

Three-dimensional solution structure of ω-conotoxin SO_(3) determined by ^(1)H NMR

Cone snails (Conus) elaborate a series of conotoxin (CTX) peptides in their venoms to paralyze their prey. Among these toxins, w-CTX抯 specifically target to presynaptic voltage-gated calcium channel subsets, causing inhibition of neurotransmitter release. w-CTX SO3 was isolated from the venom of Conus striatus, which is the only available fish-hunting snail near the coast of the South China Sea. The three-dimensional solution structure of w-CTX SO3, a peptide which is the only w-conotoxin reported to show high homology with another w-CTX (MVIIA from C. Magus), has been determined by 1H NMR techniques. The molecular structure of w-CTX SO3 is stabilized by three disulfide bridges and a short triple-stranded antiparallel b-sheet with four turns. A comprehensive comparison suggested that the backbone conformation of w-CTXs was quite conserved, while the length of b-sheet and the type of some turns might have minor differences.

安格洛苷C对照品的定值研究

目的 分别采用质量平衡法和定量核磁共振法对安格洛苷C开展对照品定值研究。方法 采用紫外光谱、红外光谱、质谱及核磁共振波谱对安格洛苷C样品进行结构确认;采用薄层色谱法和高效液相色谱法对其进行纯度检查;同时测定样品中水分、残留溶剂及炽灼残渣,进行均匀性及稳定性检查。以质量平衡法对安格洛苷C进行定值研究,计算其不确定度;并以定量核磁共振法进一步对该样品进行定值研究,加以佐证。结果 质量平衡法的定值结果为94.04%,扩展不确定度为0.088%;定量核磁共振法的定值结果为94.06%。结论 质量平衡法与定量核磁共振法对安格洛苷C定值结果基本一致。两种方法相互佐证,能够更好地保证安格洛苷C对照品定值的准确性,为该对照品的研发奠定基础。