Zanthoxylum rhetsa - a valuable source of medicinal herbs

With the desire to learn more about the chemical composition and antifungal, antibacterial and cytotoxic activities of Mac Khen (Z. rhetsa), in order to search for active ingredients that can be used to make medicine on the basis of precious medicinal herbs of Vietnam, Assoc. Prof. Dr. Nguyen Thi Hong Van and the research team from the Institute of Natural Products Chemistry carried out the topic "Research on chemical composition and biological activities of Zanthoxylum rhetsa to orient the exploitation and efficient use of this plant resource” (Project code: VAST04.06/20-21). The project was graded excellent by the Acceptance Council at the Vietnam Academy of Science and Technology.

Assoc. Prof. Dr. Nguyen Thi Hong Van

The Zanthoxylum rhetsa (Roxb.) DC., belongs to the Rutaceae family and has some other common names. According to folk medicine, the Zanthoxylum rhetsa has a bitter taste and aroma, warmth, astringent, stimulating, and digestive benefits. The bark is fragrant, tonic and cooling. The red-brown root bark has a bitter taste, pleasant aroma, warm properties, stimulating effects, anthelmintic, regulating menstruation, filtering the blood in the kidneys. The fruit is used to treat flatulence, diarrhea, rheumatism; Essential oil used to treat cholera; Bark is used to treat diarrhea, malaria, rheumatism, and loss of stomach tone. It is distributed in India, Myanmar, Laos and Vietnam. In Vietnam, it grows wild and is quite common in the northern mountainous areas and some southern provinces.

Sample image of the Zanthoxylum rhetsa

Studies on chemical composition of Zanthoxylum rhetsa in the world show that this plant is mainly composed of quinoline alkaloid compounds, in addition to some other compounds such as amide, lignan, coumarin, triterpenoids, flavonoids. Bioactivity studies have shown that many compounds obtained from this plant have remarkable biological activities such as antifungal, antibacterial, cytotoxic, analgesic, antidiarrheal, anti-worm, anti-UV, of which the most prominent is the ability to cause cancer cell toxicity and antibacterial properties.

In Vietnam, the Zanthoxylum rhetsa  is considered a specialty tree of the Northern mountainous region, especially in the provinces of Son La, Lai Chau, Dien Bien, Tuyen Quang, Lang Son, Ha Giang and some other regions such as Thanh Hoa and Nghe An. The northwestern ethnic people often use this fruit instead of pepper as a seasoning. The young leaves of this tree are also used as a seasoning. However, there have not been many studies on chemical composition or biological activity of the Zanthoxylum rhetsa  in Vietnam. So far, only a few published results have been found on the chemical composition of the Zanthoxylum rhetsa  fruit essential oil. But these are only preliminary studies on the chemical composition of essential oils without any qualitative research towards the use of highly active ingredients to make medicines.

Research methods: The isolation and purification of substances were used combined chromatographic methods, such as: thin layer chromatography on pre-coated aluminum-based silica gel thin plates DC-Aluofolien 60 F254 (Merck 1.05715), chromatography column with sorbent as normal-phase silica gel (Merck, 0.040-0.063mm), reversed phase (YMC, 30-50 µm, Fujisilisa Chemical Ltd.) or Diaion HP-20 ion exchange resin (Misubishi Chem. Ind. Co. ., Ltd.). The determination of the chemical structures of the isolated compounds was based on physical methods and spectroscopic methods such as electron-fog mass spectrometry (ESI-MS), high-resolution mass spectrometry (HR ESI-MS), one-way (1H-NMR, 13C-NMR, DEPT) and two-way (HSQC, HMBC, COSY, NOESY).

Essential oils were obtained by steam distillation on a Clavenger apparatus and their chemical composition was determined on a gas chromatograph connected to mass spectrometry (GC/MS) with a gas chromatograph HP7890A (USA) connected to a gas chromatograph Agilent5975C (USA), Wiley 275 spectrum library, NIST 98 and combined with Kovast Index. The antimicrobial activity was tested on 96-well microplates. In vitro cytotoxicity was performed by the SRB method.

The results of the group were to isolate, determine the chemical structure and the antifungal, antibacterial, and cancer cell toxicity of secondary compounds from the leaves, fruits, and bark of the Zanthoxylum rhetsa. The results have isolated and determined the structure of 15 compounds from the stem bark, of which 01 new substance is Zanthorhetsavietnamese, 08 substances from leaves and 05 substances from fruit. Several substances exhibit potential activity, notably nitidine and hesperidin. The group also studied the chemical composition and antifungal, antibacterial, and cancer cell toxicity of essential oil samples obtained from the fruit parts, leaves, twigs, twigs, and bark of the Zanthoxylum rhetsa. 


HMBC interactions of the new substance Zanthorhetsavietnamese

Through the research results, the group has found potential components in the Zanthoxylum rhetsa such as nitidine, hesperidin and essential oils that have antifungal, antibacterial, carcinogenic, and cancer cell cytotoxic activities, and the high concentrations in the plant. Therefore, in order to effectively exploit these active ingredients to orient the development into natural products with public health care value, there should be more studies on some other activities such as anti-inflammatory, analgesic, antioxidant, immune booster, acute toxicity andsemi-permanent toxicity of these components.


Translated by Tuyet Nhung
Link to Vietnamese version

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