酸枣仁是指酸枣仁的干种子。var.spinosa(Bunge)HuexH.F.Chou。种子由红棕色外套和黄色内核组成。进行了比较研究,以研究酸枣仁种皮和籽粒之间的化学成分及其相对含量的差异。首先,使用超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF/MS)对种皮和籽粒中发现的化合物进行了表征和鉴定。分析结果根据参考化合物比较初步确定了57种化合物,文献检索,和化学数据库(e。g.,MassBank)搜索;这些化合物包括14种三萜,23类黄酮,7生物碱,6羧酸,和7种其他类型的化合物。所鉴定的化合物的质量误差在5×10-6(5ppm)的质量偏差范围内。接下来,两种多元统计分析方法,即,主成分分析(PCA)和正交偏最小二乘判别分析(OPLS-DA),用于比较两个种子部分之间的差异化合物。基于>5的投影中的可变重要性(VIP)值,通过OPLS-DA筛选出总共17种差异化合物。结果表明,桦木酸,桦木醛酸,Alphitolicacid,和枣树苷Ⅰ主要存在于种皮中,而其他13种化合物,如多刺素,JjubosideA,和6-阿魏酸肉芽胞苷,主要存在于籽粒中。因此,这17种不同的化合物可以用来区分两个种子部分。最后,使用UPLC和在流动相中具有反向梯度补偿的带电气溶胶检测器(CAD)建立了半定量方法。选择了六种具有不同类型的代表性化合物来检查CAD响应一致性:黄花碱(生物碱),spinosin(黄酮),6-阿魏酸肉芽胞苷(黄酮),红枣皂苷A(三萜皂苷),枣甙B(三萜皂苷),和桦木酸(三萜酸)。结果表明,这6种化合物在不同水平下的平均响应因子的相对标准偏差(RSD)为7.04%,其响应强度相似。此外,指纹图谱中的每种化合物都表现出良好的响应一致性,得到的峰面积直接反映了各化合物的含量。根据获得的半定量指纹,桦木酸和油酸被认为是种皮的主要成分。种皮中的桦木酸含量是种仁中的约7倍。Spinosin,JjubosideA,亚油酸,桦木酸,油酸是种子仁的主要成分。种仁中的多刺素含量是种皮中的18倍。此外,种仁中的枣树苷A含量是种皮中的24倍。所提出的方法可以准确地确定主要成分,并比较这些成分在不同种子部位的相对含量。总之,本研究确定了酸枣仁种皮和籽粒的化学成分差异,并阐明了这些部位的主要成分及其相对含量。本研究结果为酸枣仁不同部位的化学成分鉴定和品质研究提供了依据,同时也促进了该中药的开发利用。
Ziziphi Spinosae Semen refers to the dried seed of Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou. The seed is composed of a reddish brown coat and a yellow kernel. A comparative study was conducted to investigate differences in the chemical composition and their relative contents between the seed coat and kernel of Ziziphi Spinosae Semen. First, the chemical compounds found in the seed coat and kernel were characterized and identified using ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). The analytical results tentatively identified 57 chemical compounds based on reference-compound comparison, literature retrieval, and chemical-database (e. g., MassBank) searches; these compounds included 14 triterpenes, 23 flavonoids, 7 alkaloids, 6 carboxylic acids, and 7 other types of compounds. The mass error of the identified compounds was within the mass deviation range of 5×10-6 (5 ppm). Next, two methods of multivariate statistical analysis, namely, principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA), were used to compare the differential compounds between the two seed parts. A total of 17 differential compounds were screened out via OPLS-DA based on a variable importance in projection (VIP) value of >5. The results revealed that betulinic acid, betulonic acid, alphitolic acid, and jujuboside Ⅰ mainly existed in the seed coat whereas the 13 other compounds, such as spinosin, jujuboside A, and 6‴-feruloylspinosin, mainly existed in the seed kernel. Therefore, these 17 differential compounds can be used to distinguish between the two seed parts. Finally, a semiquantitative method was established using UPLC and a charged aerosol detector (CAD) with inverse gradient compensation in the mobile phase. Six representative compounds with different types were selected to examine the CAD response consistency: magnoflorine (alkaloid), spinosin (flavone), 6‴-feruloylspinosin (flavone), jujuboside A (triterpenoid saponin), jujuboside B (triterpenoid saponin), and betulinic acid (triterpenoid acid). The results showed that the relative standard deviation (RSD) of the average response factors at different levels of these six compounds was 7.04% and that their response intensities were similar. Moreover, each compound in the fingerprint demonstrated good response consistency, and the peak areas obtained directly reflected the contents of each compound. Based on the semiquantitative fingerprints obtained, betulinic acid and oleic acid were considered the main components of the seed coat. The betulinic acid content in the seed coat was approximately 7 times higher than that in the seed kernel. Spinosin, jujuboside A, linoleic acid, betulinic acid, and oleic acid were the main components of the seed kernel. The spinosin content in the seed kernel was 18 times higher than that in the seed coat. In addition, the jujuboside A content in the seed kernel was 24 times higher than that in the seed coat. The proposed method can accurately determine the main components and compare the relative contents of these components in different seed parts. In summary, this study identified the differences in chemical components between the seed coat and kernel of Ziziphi Spinosae Semen and clarified the main components and their relative contents in these parts. The findings can not only provide a basis for the identification of chemical compounds and quality research on different parts of Ziziphi Spinosae Semen but also promote the development and utilization of this traditional Chinese medicine.