How to Make an Accurate Determination? The Chemical Differences between Ziziphi Spinosae Semen and Ziziphi Mauritianae Semen Are Significant.
As the first choice of traditional Chinese medicine for the treatment of insomnia, Ziziphi Spinosae Semen (ZSS) has a clinical history of over 2,000 years, and its authentic medicinal materials are produced in the northern region of China. In contrast, Ziziphi Mauritianae Semen (ZMS) is a modern medicine mainly distributed in the southwestern region of China. In recent years, due to the similar morphological characteristics and therapeutic effects of the two herbs, but a significant difference in market prices, it has become increasingly common for ZMS to be fraudulently labeled or adulterated as ZSS, leading to confusion in the Chinese herbal medicine market and clinical applications.
What are the characteristics that distinguish ZSS from ZMS, and how can they be accurately distinguished?
酸枣仁 （Ziziphi Spinosae Semen，ZSS）为鼠李科枣属植物酸枣 Z. jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chow的干燥成熟种子，始载于《神农本草经》，位列上品，历代本草皆有收录。其味甘、酸，性平，归肝、胆、心经，具有养心补肝、宁心安神、敛汗、生津之功效。作为中药治疗失眠的首选药物，酸枣仁在治疗失眠相关的药方中使用率高达70%以上。
理枣仁 （Ziziphi Mauritianae Semen，ZMS）为酸枣仁同科同属植物滇刺枣 Z. mauritiana Lam. 的干燥成熟种子，也称“滇枣仁”、“缅枣仁”或“进口酸枣仁”等，为近现代用药，仅在《滇南本草》中有过收录。其味甘、平，归心、肝经，具有宁心安神，除烦敛汗的功效。在云南民间被作为治疗失眠的习用药材使用。
1 Pharmacopoeia Inclusion and Categorization
ZSS, also known as sour jujube seed, is the dried mature seed of the plant Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chow, which belongs to the Rhamnaceae family. It was first recorded in the classic Chinese herbal book "Shennong Bencao Jing" and was listed as a top-grade herb. It has been included in nearly all Chinese pharmacopoeias throughout history. ZSS is associated with the liver, gallbladder, and heart meridians，possess the effects of nourishing the heart and liver, calming the mind and tranquilizing the nerves, according to the theory of Traditional Chinese Medicines. As the first choice for treating insomnia in Traditional Chinese Medicines, ZSS is used in over 70% of insomnia-related prescriptions.
ZMS, also known as "Dian zao ren", "Mian zao ren", or "imported sour jujube kernel", is the dried mature seed of Ziziphi mauritiana Lam., a plant belonging to the same family and genus as ZSS, but a different species. It is a relatively modern medicinal material and has only been recorded in the "Dian Nan Ben Cao". ZMS is associated with the heart and liver meridians, and is known for its calming and sweat-reducing effects, according to TCMs. ZMS is commonly used in Yunnan folk medicine to treat insomnia.
2 Chemical Differences between ZSS and ZMS
It has been discovered by modern pharmacological research that both ZSS and ZMS are rich in triterpenoids, flavonoids, alkaloids, and nucleoside. However, there are also significant differences in the types and contents of these compounds between ZSS and ZMS.
酸枣仁和理枣仁所含三萜皂苷类成分差异较大，酸枣仁中皂苷类成分的种类和数量均明显多于理枣仁。研究表明，酸枣仁中总皂苷含量约为 0.09%，而理枣仁中总皂苷含量约为0.04%。其中，以酸枣仁皂苷 A为代表的达玛烷型四环三萜是酸枣仁中含量最多的一类三萜皂苷，酸枣仁皂苷 A和酸枣仁皂苷 B一般被认为酸枣仁的特征成分。而理枣仁的特征成分是白桦酯醛，理枣仁中一般检测不到酸枣仁皂苷 A，酸枣仁皂苷 B的含量也低于酸枣仁。
There is a significant difference in the triterpenoids between ZSS and ZMS. The variety and content of saponins in ZSS are significantly higher than those in ZMS. It is revealed that the total saponins in ZSS is approximately 0.09%, while that in ZMS is approximately 0.04%. Among them, dammarane-type tetracyclic triterpenoids, represented by jujuboside A (JuA), are the most abundant type of triterpenoids in ZSS. JuA and jujuboside B (JuB) are also generally considered to be the characteristic components of ZSS. The characteristic component of ZMS is betulinic aldehyde, and JuA is not detected in ZMS, while the content of JuB is lower than that in ZSS.
With more skeleton types of flavonoids in ZSS, the content of total flavonoids in ZSS is about 0.95%, which is significantly lower than that in ZMS. Spinosin and its derivatives, which have a skeleton of glycoside located at C-6 site of apigenin with a carbon atom, are common flavonoids in ZSS and ZMS. As reported in the literatures, the content of flavonoids such as spinosin, 6′′′-sinapoyl spinosin, and 6′′′-feruloyl spinosin in ZSS are all significantly lower than that in ZMS.
酸枣仁生物碱主要包含异喹啉类生物碱、阿朴菲类生物碱和环肽类生物碱，其中，异喹啉类生物碱含量相对较高；理枣仁中的生物碱主要为环肽类生物碱。酸枣仁中木兰花碱的含量约为理枣仁的 2 倍，乌药碱、酸李碱和莲心季铵碱的含量也明显高于理枣仁。
The main alkaloids in ZSS include isoquinoline alkaloids, aporphine alkaloids, and cyclic peptide alkaloids. Among them, the content of isoquinoline alkaloids is higher. In contrast, alkaloids forming as cyclic peptide alkaloids are the main alkaloids in ZMS. The content of magnoflorine in ZSS is about twice that of ZMS. The content of coclaurine, zizyphusine, and lotusine are also significantly higher in ZSS compared to ZMS, respectively.
酸枣仁和理枣仁均含有丰富的氨基酸。迄今，酸枣仁中已检测到 22 种氨基酸，理枣仁中已检测到 19 种氨基酸。酸枣仁中必须氨基酸的总含量约为理枣仁的 8 倍。酸枣仁中精氨酸、天冬酰胺、丝氨酸和酪氨酸等氨基酸含量较高，约占总氨基酸含量的50%，而理枣仁中精氨酸和丝氨酸含量较高。理枣仁中缬氨酸和蛋氨酸含量明显高于酸枣仁。
2.4 Amino Acids and Nucleoside
The content of amino acids in both ZSS and ZMS are rich. To date, 22 types of amino acids have been detected in ZSS and 19 types have been detected in ZMS. The total content of essential amino acids in ZSS is approximately eight times higher than those in ZMS. Arginine, asparagine, serine, and tyrosine are richer in ZSS, accounting for about 50% of the total amino acid content, while the content of arginine and serine are higher in ZMS. However, the contents of methionine and lysine in ZMS are significantly higher than those in ZSS.
In addition, the types and content of nucleosides in ZSS are higher than those in ZMS, especially adenosine, uridine, and adenine, which account for more than 60% of the total nucleic acid and base.
In conclusion, there are significant chemical differences between ZSS and ZMS, which can be quickly and accurately identified by modern detection technology. It is very important and urgent to accurately distinguish the authenticity and quality of ZSS，which is crucial to maintain normal market order, safeguard the legitimate rights and interests of consumers, and ensure the healthy development of the traditional Chinese medicine industry.