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[Methods] Microscopic identification and thin layer chromatography were used to identify and determine the moisture， total ash and extract contents.
[Results] According to the microscopic results， the stem transection is round and has five longitudinal edges at which the cell wall is obviously thickened. Bristles can be observed. A series of collenchyma cells are arranged closely inside the epidermis. There are several rows of parenchyma cells. The vascular bundles are of different sizes; and the ray part is wide， and at the junction of the ray and the cortex， there are often scattered secretory cells. The center is a broad medulla. The powder is brown. There are many starch grains. The bristles are unicelluar， and have warty protrusions and expanded base. The fibers are bundled， and the cells are large. The epidermal cells are in the shape of an elongated spindle， in a mosaic arrangement， and the cell wall is slightly thickened. From the thin layer identification chromatograms of tested L. bulbifera， it can be seen that spots were observed at the same positions as the control medicinal material， and the durability of the method was good. The extract content should not be less than 12.00% by hot extraction with water as solvent， and not be less than 3.00% by cold extraction with ethanol as solvent. The moisture content should not be more than 16.50%. The total ash content should not be more than 14.00%. The acidinsoluble ash content should not be more than 2.50%.
[Conclusions] The microscopic identification results are reliable and can be used as the identification basis of L. bulbifera. The thin layer identification method and the test results can provide a basis for quality control of L. bulbifera.
Key words Laportea bulbifera （Sieb. et Zucc.） Wedd.; Quality standard; Thin layer chromatography
Laportea bulbifera （Sieb. et Zucc.） Wedd. is a plant in Urticaceae， also known as Yeluma， Honghuoma， etc. It is used as a windexpelling drug in 104 classic Yao medicines （Laobanyao）. Its medicinal value， original plant and geographical distribution are briefly described in Guangxi Yaoyongzhiwu Minglu （Guangxi Medicinal Plants List）， Guangxi Bencao Xuanbian （Guangxi Herbal Selection）， Zhongyao Dacidian （Dictionary of Traditional Chinese Medicine）， Chinese Materia Medica， Quanguo Zhongcaoyao Huibian （National Chinese herbal Medicine Compilation）， Zhongguo Xiandai Yaoyao （Chinese Modern Yao Medicine） and other books. L. bulbifera has not been recorded in Chinese Pharmacopoeia and local standards. L. bulbifera is produced in Heilongjiang， Jilin， Liaoning， Shandong， Hebei， Shanxi， Henan， Anhui， Shaanxi， Gansu， Sichuan， Tibet， Yunnan， Guizhou， northwestern Guangxi， northern Guangdong， Hunan， Hubei， Jiangxi， Zhejiang， and northern Fujian. It grows under hillside forests or at the edge of the forests on semishady slope areas， with an altitude of 1 000 to 2 400 m[1]. In Guangxi， it is distributed in Rongshui， Longsheng， Debao， Jingxi， Napo， Longlin， Zhongshan， Fuchuan， Jinxiu and Longzhou. In order to better develop and utilize plant resources， L. bulbifera materials were identified by microscope observation and thin layer chromatography， and the contents of moisture， total ash， acidinsoluble ash and extract were determined， laying a foundation for the development of the quality control standards of L. bulbifera and the development of new medicines. Materials and Methods
Materials and reagents
The L. bulbifera medicinal materials were collected from Jinxiu Town of Jinxiu County （CSF1）， Jinxiu County， 16 km （CSF2）， Gonghe Township of Jinxiu County （CSF3）， Hurun Town of Jingxi County （CSF4）， Jinxiu Town of Jinxiu County （CSF5）， and Zurong Town of Debao County （CSF6）. These materials were identified as the whole herb of L. bulbifera by Professor Wei from Guangxi University of Chinese Medicine. In this experiment， CSF2 was used as a control material which was compared with other samples. Reagents including chloroform， ethyl acetate and nbutanol were all analytical pure.
Instruments
Sartorius BS214D electronic analytical balance （Sartorius Scientific Instruments（Beijing） Co.， Ltd.）; DF20 desktop continuous feeding mill （Wenling Linda Machinery Co.， Ltd.）; HH4 digital thermostat water bath （Guohua Electric Appliance Co.， Ltd.）; 101A3E electrothermal blowing dry box （Shanghai Testing Instrument Co.， Ltd.）; SX2 chamber electric furnace （Shanghai Testing Instrument Co.， Ltd.）; SK2200LHC ultrasonic cleaning instrument （Shanghai Kudos Ultrasonic Instrument Co.， Ltd.）; DM2500M biological microscope （Leica Instrument Co.， Ltd.）.
Experiment methods
The parts of fresh L. bulbifera materials with a diameter of 3-10 mmwere taken and prepared into permanent slides by paraffin sectioning and double staining. The root and the leaf samples were also dried， pulverized and sieved with a 60 mesh sieve， and prepared into slides with dilute glycerin. The slides were observed and imaged with a DM2500M biological microscope. Extract， moisture and ash were determined in accordance with the 2015 editionof Chinese Pharmacopoeia （the fourth part）.
Results and Analysis
Observation of fresh L. bulbifera
Stem transection
The stem transection is round and has five longitudinal edges. There is one column of epidermal cells， and the cell wall located at the edges is obviously thickened; and bristles can be observed. A series of collenchyma cells are arranged closely inside the epidermis. The cortex is narrow， and there are several rows of parenchyma cells. The phloem is narrow; the vascular bundles are of different sizes; the ray part is wide， and there are more than 2 to 20 columns of cells; and at the junction of the ray and the cortex， there are often scattered secretory cells. The center is a broad medulla （Fig. 1）. Power characteristics
The powder is brown. There are many starch grains， in the shape of umbilical point， exhibiting with obvious laminated striation， and they are often gathered or stored in parenchyma cells， and have a diameter of 5-40 μm. There are visible halfcompound starch grains. The bristles are unicelluar， containing yellow substance， 150-180 μm in length， and have warty protrusions and expanded base. The fibers are bundled， the cells are large， and the pits are obvious. They also can be scattered， and the cells are linear. The vessels are spiral vessels， bordered pit vessels and scalariform vessels， with a diameter of 15-100 μm.The secretory cells are round and have a diameter of 110-180 μm. The epidermal cells are in the shape of an elongated spindle， in a mosaic arrangement， and the cell wall is slightly thickened （Fig. 2）.
Extract determination
The extracts were obtained by cold extraction method and hot extraction method with water and 95% ethanol， respectively， and then determined according to "extract determination method" in Chinese Pharmacopeoia （2015 edition）. Six batches of extracts were obtained， and the determination results are shown in Table 1-Table 4.
In summary， the results of various extraction methods were compared and analyzed. Combined with the chemical composition pretest， the results showed that the extraction amount of the hot extraction method with water was higher than that of cold extraction method. With ethanol as the solvent， the extraction amount of the hot extraction method was not much different from that of cold extraction method. Therefore， it was determined that the extract content of the product can be determined by cold ethanol extraction method or hot water extraction method. When water is used as the solvent， and the limit of the hot extraction method should not be less than 12.00%， which is included in the standard; and when ethanol is used as the solvent， and the limit of cold extraction method should not be less than 3.00%， which is included in the standard.
Moisture determination
Moisture was determined according to "the first method for determination of moisture" in Chinese Pharmacopeoia （2015 edition）. The results are shown in Table 5.
It can be seen from the above results that the moisture contents of the 6 batches of samples were the highest at 13.73% and the lowest at 12.86%. The moisture content of this product should not be more than 16.50%， which is included in the standard. Total ash determination
The total ash contents were determined according to "ash determination method" in Chinese Pharmacopeoia （2015 edition）. The results are shown in Table 6.
It can be seen from the above results that the total ash contents of the 6 batches of samples were the highest at 11.31% and the lowest at 8.53%. The total ash content of this product should not be more than 14.00%， which is included in the standard.
Acidinsoluble ash
Acidinsoluble ash was determined according to "Acidinsoluble ash determination method" in Chinese Pharmacopeoia （2015 edition）. The results are shown in Table 7.
Agricultural Biotechnology 2020
It can be seen from the above results that the acidinsoluble ash contents of the 6 batches of samples were the highest at 2.04%and the lowest at 0.58%. The acidinsoluble ash content of this product should not be more than 2.50%， which is included in the standard.
In summary， the results of various extraction methods were compared and analyzed. Combined with the chemical composition pretest， the results showed that the extraction amount of hot extraction with water as solvent was higher than that of cold extraction method. The amount of hot extraction with ethanol as solvent was not much different from that of cold extraction method. Therefore， it is determined that the content of the product can be determined by cold ethanol extraction method and hot water extraction method. When water is used as the solvent， the limit of hot extraction method should not be less than 12.00%， which is included in the standard; and when ethanol is used as the solvent， the limit of cold extraction method should not be less than 3.00%， which is included in the standard.
Thinlayer chromatography identification
Because no specific index components were found in L. bulbifera， so the control medicinal material was used as a control. The coarse powder of the product was sieved with a No. 2 sieve， and a certain amount of the obtained powder （2 g） was added with 20 ml of 95% ethanol， and refluxextracted for 60 min with heating. The extracting system was filtered， obtaining the filtrate， which was a test solution. The control medicinal material was also taken and prepared according to this method to a control solution. Testing was then carried out according to 0502 thinlayer chromatography under "chromatography" in Chinese Pharmacopeoia （2015 edition）. Specifically， 10 μl was taken from the above two solutions and applied on the same silica gel G thin layer plate， respectively. Development was performed with petroleum etheracetone （2∶ 1） as a developing solvent， followed by taking out and air drying. The silica gel G thin layer plate was then sprayed with 5% phosphomolybdic acid solution and heated at 105 ℃ until the spots were clear. The results showed that in the chromatogram of each test sample， the same fluorescent spots were displayed at the positions corresponding to the chromatogram of the control medicinal material， and the reproducibility was good. Durability test： ① The developing effects of the selfmade plate and prefabricated plate （provided by Qingdao Haiyang Chemical Co.， Ltd.， lot number： 20111216） were investigated. ② Different developing temperatures （5 and 28 ℃） were investigated. ③ The dotlike and striplike sample applying methods were investigated. The results of the investigations showed that the durability of the method was good.
Different developing systems were compared， including ethyl acetate：petroleum ether （3∶ 1）， chloroform∶ methanol （5∶ 1）， chloroform∶ methanol∶ formic acid （3∶ 1∶ 0.5） and petroleum ether∶ acetone （2∶ 1）. Finally， petroleum ether∶ acetone （2∶ 1） was selected as the developing agent as it showed a better development effect with separated and clear spots. Therefore， the system was selected as the developing agent for thin layer identification. Amongvarious developing methods， spraying 5% phosphomolybdic acid solution followed by heating at 105 ℃ until the spots are clear was selected.
From the thin layer identification chromatograms of the 6 batches of L. bulbifera， it can be seen that for each batch of L. bulbifera， spots were observed at the same positions as the control medicinal material， as shown in Fig. 3.
Conclusions and Discussion
According to the microscopic results， the stem transection is round and has five longitudinal edges at which the cell wall is obviously thickened. Bristles can be observed. A series of collenchyma cells are arranged closely inside the epidermis. There are several rows of parenchyma cells. The vascular bundles are of different sizes; and the ray part is wide， and at the junction of the ray and the cortex， there are often scattered secretory cells. The center is a broad medulla. The powder is brown. There are many starch grains. The bristles are unicelluar， and have warty protrusions and expanded base. The fibers are bundled， and the cells are large. The epidermal cells are in the shape of an elongated spindle， in a mosaic arrangement， and the cell wall is slightly thickened.
The results of various determination items showed that the moisture content， total ash content， acidinsoluble ash content and watersoluble extract and alcoholsoluble extract contents of the L. bulbifera medicinal materials were in accordance with related requirements for the first method for determination of moisture （drying method）， ash determination method and extraction determination method in Chinese Pharmacopeoia （2015 edition）. The moisture contents of the 6 batches of samples were the highest at 13.73% and the lowest at 12.86%. The moisture content of this product should not be more than 16.50%， which is included in the standard. The total ash contents of the 6 batches of samples were the highest at 11.31% and the lowest at 8.53%. The total ash content of this product should not be more than 14.00%， which is included in the standard. The acidinsoluble ash contents of the 6 batches of samples were the highest at 2.04% and the lowest at 0.58%. The acidinsoluble ash content of this product should not be more than 2.50%， which is included in the standard.
Chromatographic conditions： Silica gel G thin layer plate （Qingdao Haiyang Chemical Co.， Ltd.， lot number： 20111216， specification： 10 cm×20 cm）; dotlike sample application， sample application amount： 10 μl; temperature： 26 ℃ （±2 ℃）; relative humidity： 68RH% （±4%）; the developing agent： petroleum ether：acetone （2∶ 1）.
Fig. 3 TCL image of L. bulbifera （natural light）
The results of thin layer identification showed that in the chromatograms of L. bulbifera， each batch of L. bulbifera showed spots of the same colors at the same positions in the chromatogram of the control material HGT5. The reproducibility was good.
References
[1] Editorial Board of Flora of China， Chinese Academy of Sciences. Flora of China[M]. Beijing： Science Press， 1995. （in Chinese）
[2] Editorial Board of Chinese Materia Medica， State Administration of Traditional Chinese Medicine. Chinese materia medica[M]. Shanghai： Shanghai Scientific and Technical Publishers， 1999. （in Chinese）
[3] DAI B. Chinese modern Yao medicine[M]. Nanning： Guangxi Science and Technology Press， 2009： 216-217. （in Chinese）
[4] ZHU L， MA L， ZHU HY， et al. Study on chemical constituents of ethnodrug Laportea bulbifera （Sieb. et Zucc.） Wedd.[J]. Journal of Chinese Medicinal Materials， 2011， 34（2）： 223-225. （in Chinese）
[5] MA L， LIANG B， ZHU Z， et al. Study on the pharmacological analgesic effects of alcohol extract of ethnodrug Laportea bulbifera （Sieb. et Zucc.） Wedd.[J]. Journal of Guiyang College of Traditional Chinese Medicine， 2012， 34（1）： 24-26. （in Chinese）
[Results] According to the microscopic results， the stem transection is round and has five longitudinal edges at which the cell wall is obviously thickened. Bristles can be observed. A series of collenchyma cells are arranged closely inside the epidermis. There are several rows of parenchyma cells. The vascular bundles are of different sizes; and the ray part is wide， and at the junction of the ray and the cortex， there are often scattered secretory cells. The center is a broad medulla. The powder is brown. There are many starch grains. The bristles are unicelluar， and have warty protrusions and expanded base. The fibers are bundled， and the cells are large. The epidermal cells are in the shape of an elongated spindle， in a mosaic arrangement， and the cell wall is slightly thickened. From the thin layer identification chromatograms of tested L. bulbifera， it can be seen that spots were observed at the same positions as the control medicinal material， and the durability of the method was good. The extract content should not be less than 12.00% by hot extraction with water as solvent， and not be less than 3.00% by cold extraction with ethanol as solvent. The moisture content should not be more than 16.50%. The total ash content should not be more than 14.00%. The acidinsoluble ash content should not be more than 2.50%.
[Conclusions] The microscopic identification results are reliable and can be used as the identification basis of L. bulbifera. The thin layer identification method and the test results can provide a basis for quality control of L. bulbifera.
Key words Laportea bulbifera （Sieb. et Zucc.） Wedd.; Quality standard; Thin layer chromatography
Laportea bulbifera （Sieb. et Zucc.） Wedd. is a plant in Urticaceae， also known as Yeluma， Honghuoma， etc. It is used as a windexpelling drug in 104 classic Yao medicines （Laobanyao）. Its medicinal value， original plant and geographical distribution are briefly described in Guangxi Yaoyongzhiwu Minglu （Guangxi Medicinal Plants List）， Guangxi Bencao Xuanbian （Guangxi Herbal Selection）， Zhongyao Dacidian （Dictionary of Traditional Chinese Medicine）， Chinese Materia Medica， Quanguo Zhongcaoyao Huibian （National Chinese herbal Medicine Compilation）， Zhongguo Xiandai Yaoyao （Chinese Modern Yao Medicine） and other books. L. bulbifera has not been recorded in Chinese Pharmacopoeia and local standards. L. bulbifera is produced in Heilongjiang， Jilin， Liaoning， Shandong， Hebei， Shanxi， Henan， Anhui， Shaanxi， Gansu， Sichuan， Tibet， Yunnan， Guizhou， northwestern Guangxi， northern Guangdong， Hunan， Hubei， Jiangxi， Zhejiang， and northern Fujian. It grows under hillside forests or at the edge of the forests on semishady slope areas， with an altitude of 1 000 to 2 400 m[1]. In Guangxi， it is distributed in Rongshui， Longsheng， Debao， Jingxi， Napo， Longlin， Zhongshan， Fuchuan， Jinxiu and Longzhou. In order to better develop and utilize plant resources， L. bulbifera materials were identified by microscope observation and thin layer chromatography， and the contents of moisture， total ash， acidinsoluble ash and extract were determined， laying a foundation for the development of the quality control standards of L. bulbifera and the development of new medicines. Materials and Methods
Materials and reagents
The L. bulbifera medicinal materials were collected from Jinxiu Town of Jinxiu County （CSF1）， Jinxiu County， 16 km （CSF2）， Gonghe Township of Jinxiu County （CSF3）， Hurun Town of Jingxi County （CSF4）， Jinxiu Town of Jinxiu County （CSF5）， and Zurong Town of Debao County （CSF6）. These materials were identified as the whole herb of L. bulbifera by Professor Wei from Guangxi University of Chinese Medicine. In this experiment， CSF2 was used as a control material which was compared with other samples. Reagents including chloroform， ethyl acetate and nbutanol were all analytical pure.
Instruments
Sartorius BS214D electronic analytical balance （Sartorius Scientific Instruments（Beijing） Co.， Ltd.）; DF20 desktop continuous feeding mill （Wenling Linda Machinery Co.， Ltd.）; HH4 digital thermostat water bath （Guohua Electric Appliance Co.， Ltd.）; 101A3E electrothermal blowing dry box （Shanghai Testing Instrument Co.， Ltd.）; SX2 chamber electric furnace （Shanghai Testing Instrument Co.， Ltd.）; SK2200LHC ultrasonic cleaning instrument （Shanghai Kudos Ultrasonic Instrument Co.， Ltd.）; DM2500M biological microscope （Leica Instrument Co.， Ltd.）.
Experiment methods
The parts of fresh L. bulbifera materials with a diameter of 3-10 mmwere taken and prepared into permanent slides by paraffin sectioning and double staining. The root and the leaf samples were also dried， pulverized and sieved with a 60 mesh sieve， and prepared into slides with dilute glycerin. The slides were observed and imaged with a DM2500M biological microscope. Extract， moisture and ash were determined in accordance with the 2015 editionof Chinese Pharmacopoeia （the fourth part）.
Results and Analysis
Observation of fresh L. bulbifera
Stem transection
The stem transection is round and has five longitudinal edges. There is one column of epidermal cells， and the cell wall located at the edges is obviously thickened; and bristles can be observed. A series of collenchyma cells are arranged closely inside the epidermis. The cortex is narrow， and there are several rows of parenchyma cells. The phloem is narrow; the vascular bundles are of different sizes; the ray part is wide， and there are more than 2 to 20 columns of cells; and at the junction of the ray and the cortex， there are often scattered secretory cells. The center is a broad medulla （Fig. 1）. Power characteristics
The powder is brown. There are many starch grains， in the shape of umbilical point， exhibiting with obvious laminated striation， and they are often gathered or stored in parenchyma cells， and have a diameter of 5-40 μm. There are visible halfcompound starch grains. The bristles are unicelluar， containing yellow substance， 150-180 μm in length， and have warty protrusions and expanded base. The fibers are bundled， the cells are large， and the pits are obvious. They also can be scattered， and the cells are linear. The vessels are spiral vessels， bordered pit vessels and scalariform vessels， with a diameter of 15-100 μm.The secretory cells are round and have a diameter of 110-180 μm. The epidermal cells are in the shape of an elongated spindle， in a mosaic arrangement， and the cell wall is slightly thickened （Fig. 2）.
Extract determination
The extracts were obtained by cold extraction method and hot extraction method with water and 95% ethanol， respectively， and then determined according to "extract determination method" in Chinese Pharmacopeoia （2015 edition）. Six batches of extracts were obtained， and the determination results are shown in Table 1-Table 4.
In summary， the results of various extraction methods were compared and analyzed. Combined with the chemical composition pretest， the results showed that the extraction amount of the hot extraction method with water was higher than that of cold extraction method. With ethanol as the solvent， the extraction amount of the hot extraction method was not much different from that of cold extraction method. Therefore， it was determined that the extract content of the product can be determined by cold ethanol extraction method or hot water extraction method. When water is used as the solvent， and the limit of the hot extraction method should not be less than 12.00%， which is included in the standard; and when ethanol is used as the solvent， and the limit of cold extraction method should not be less than 3.00%， which is included in the standard.
Moisture determination
Moisture was determined according to "the first method for determination of moisture" in Chinese Pharmacopeoia （2015 edition）. The results are shown in Table 5.
It can be seen from the above results that the moisture contents of the 6 batches of samples were the highest at 13.73% and the lowest at 12.86%. The moisture content of this product should not be more than 16.50%， which is included in the standard. Total ash determination
The total ash contents were determined according to "ash determination method" in Chinese Pharmacopeoia （2015 edition）. The results are shown in Table 6.
It can be seen from the above results that the total ash contents of the 6 batches of samples were the highest at 11.31% and the lowest at 8.53%. The total ash content of this product should not be more than 14.00%， which is included in the standard.
Acidinsoluble ash
Acidinsoluble ash was determined according to "Acidinsoluble ash determination method" in Chinese Pharmacopeoia （2015 edition）. The results are shown in Table 7.
Agricultural Biotechnology 2020
It can be seen from the above results that the acidinsoluble ash contents of the 6 batches of samples were the highest at 2.04%and the lowest at 0.58%. The acidinsoluble ash content of this product should not be more than 2.50%， which is included in the standard.
In summary， the results of various extraction methods were compared and analyzed. Combined with the chemical composition pretest， the results showed that the extraction amount of hot extraction with water as solvent was higher than that of cold extraction method. The amount of hot extraction with ethanol as solvent was not much different from that of cold extraction method. Therefore， it is determined that the content of the product can be determined by cold ethanol extraction method and hot water extraction method. When water is used as the solvent， the limit of hot extraction method should not be less than 12.00%， which is included in the standard; and when ethanol is used as the solvent， the limit of cold extraction method should not be less than 3.00%， which is included in the standard.
Thinlayer chromatography identification
Because no specific index components were found in L. bulbifera， so the control medicinal material was used as a control. The coarse powder of the product was sieved with a No. 2 sieve， and a certain amount of the obtained powder （2 g） was added with 20 ml of 95% ethanol， and refluxextracted for 60 min with heating. The extracting system was filtered， obtaining the filtrate， which was a test solution. The control medicinal material was also taken and prepared according to this method to a control solution. Testing was then carried out according to 0502 thinlayer chromatography under "chromatography" in Chinese Pharmacopeoia （2015 edition）. Specifically， 10 μl was taken from the above two solutions and applied on the same silica gel G thin layer plate， respectively. Development was performed with petroleum etheracetone （2∶ 1） as a developing solvent， followed by taking out and air drying. The silica gel G thin layer plate was then sprayed with 5% phosphomolybdic acid solution and heated at 105 ℃ until the spots were clear. The results showed that in the chromatogram of each test sample， the same fluorescent spots were displayed at the positions corresponding to the chromatogram of the control medicinal material， and the reproducibility was good. Durability test： ① The developing effects of the selfmade plate and prefabricated plate （provided by Qingdao Haiyang Chemical Co.， Ltd.， lot number： 20111216） were investigated. ② Different developing temperatures （5 and 28 ℃） were investigated. ③ The dotlike and striplike sample applying methods were investigated. The results of the investigations showed that the durability of the method was good.
Different developing systems were compared， including ethyl acetate：petroleum ether （3∶ 1）， chloroform∶ methanol （5∶ 1）， chloroform∶ methanol∶ formic acid （3∶ 1∶ 0.5） and petroleum ether∶ acetone （2∶ 1）. Finally， petroleum ether∶ acetone （2∶ 1） was selected as the developing agent as it showed a better development effect with separated and clear spots. Therefore， the system was selected as the developing agent for thin layer identification. Amongvarious developing methods， spraying 5% phosphomolybdic acid solution followed by heating at 105 ℃ until the spots are clear was selected.
From the thin layer identification chromatograms of the 6 batches of L. bulbifera， it can be seen that for each batch of L. bulbifera， spots were observed at the same positions as the control medicinal material， as shown in Fig. 3.
Conclusions and Discussion
According to the microscopic results， the stem transection is round and has five longitudinal edges at which the cell wall is obviously thickened. Bristles can be observed. A series of collenchyma cells are arranged closely inside the epidermis. There are several rows of parenchyma cells. The vascular bundles are of different sizes; and the ray part is wide， and at the junction of the ray and the cortex， there are often scattered secretory cells. The center is a broad medulla. The powder is brown. There are many starch grains. The bristles are unicelluar， and have warty protrusions and expanded base. The fibers are bundled， and the cells are large. The epidermal cells are in the shape of an elongated spindle， in a mosaic arrangement， and the cell wall is slightly thickened.
The results of various determination items showed that the moisture content， total ash content， acidinsoluble ash content and watersoluble extract and alcoholsoluble extract contents of the L. bulbifera medicinal materials were in accordance with related requirements for the first method for determination of moisture （drying method）， ash determination method and extraction determination method in Chinese Pharmacopeoia （2015 edition）. The moisture contents of the 6 batches of samples were the highest at 13.73% and the lowest at 12.86%. The moisture content of this product should not be more than 16.50%， which is included in the standard. The total ash contents of the 6 batches of samples were the highest at 11.31% and the lowest at 8.53%. The total ash content of this product should not be more than 14.00%， which is included in the standard. The acidinsoluble ash contents of the 6 batches of samples were the highest at 2.04% and the lowest at 0.58%. The acidinsoluble ash content of this product should not be more than 2.50%， which is included in the standard.
Chromatographic conditions： Silica gel G thin layer plate （Qingdao Haiyang Chemical Co.， Ltd.， lot number： 20111216， specification： 10 cm×20 cm）; dotlike sample application， sample application amount： 10 μl; temperature： 26 ℃ （±2 ℃）; relative humidity： 68RH% （±4%）; the developing agent： petroleum ether：acetone （2∶ 1）.
Fig. 3 TCL image of L. bulbifera （natural light）
The results of thin layer identification showed that in the chromatograms of L. bulbifera， each batch of L. bulbifera showed spots of the same colors at the same positions in the chromatogram of the control material HGT5. The reproducibility was good.
References
[1] Editorial Board of Flora of China， Chinese Academy of Sciences. Flora of China[M]. Beijing： Science Press， 1995. （in Chinese）
[2] Editorial Board of Chinese Materia Medica， State Administration of Traditional Chinese Medicine. Chinese materia medica[M]. Shanghai： Shanghai Scientific and Technical Publishers， 1999. （in Chinese）
[3] DAI B. Chinese modern Yao medicine[M]. Nanning： Guangxi Science and Technology Press， 2009： 216-217. （in Chinese）
[4] ZHU L， MA L， ZHU HY， et al. Study on chemical constituents of ethnodrug Laportea bulbifera （Sieb. et Zucc.） Wedd.[J]. Journal of Chinese Medicinal Materials， 2011， 34（2）： 223-225. （in Chinese）
[5] MA L， LIANG B， ZHU Z， et al. Study on the pharmacological analgesic effects of alcohol extract of ethnodrug Laportea bulbifera （Sieb. et Zucc.） Wedd.[J]. Journal of Guiyang College of Traditional Chinese Medicine， 2012， 34（1）： 24-26. （in Chinese）