Synergistic inhibition effects of bamboo leaf extract/major components and iodide ion on the corrosion of steel in H3PO4 solution

The corrosion inhibition by Dendrocalamus brandisii leaves extract (DBLE)/major flavonoid of cold rolled steel (CRS) in trichloroacetic acid (Cl3CCOOH) solution was investigated by weight loss, electrochemical techniques and atomic force microscope (AFM). The adsorption mode of four major compounds (rutin, vientin, isovientin and orientin) on Fe (001) surface was theoretically investigated by molecular dynamics (MD). The results show that DBLE is a good inhibitor, and the maximum inhibition efficiency is higher than 95%. The adsorption of DBLE on CRS surface obeys Langmuir isotherm with exothermic process. DBLE behaves as a mixed inhibitor. AFM results confirm that DBLE could retard the corrosion of CRS in Cl3CCOOH. The inhibitive action of each flavonoid is lower than DBLE, and follows the order: rutin > vientin > isovientin > orientin. The major flavonoids in DBLE are adsorbed onto Fe (001) surface through FBS (flavones backbone structure) with a nearby flat orientation.

Inhibition effect of bamboo leaves extract on cold rolled steel in Cl3CCOOH solution

A reversed phase high performance liquid chromatography (RP-HPLC) method was described for simultaneous determination of seven effective constituents (orientin, isoorientin, vitexin, isovitexin, chlorogenic acid, caffeic acid and ferulic acid) in Bamboo leaf from nine cultivars of Phyllostachys pubescens. The seven compounds were simultaneously determined by HPLC with Sunfire C18 ODS column (4.6 × 250 mm, 5 μm) by gradient elution using acetonitrile (A) and 0.8% acetic acid (B) as the mobile phase. The flow rate was 1.0 mL·min-1; the detection wavelength was 335 nm with column temperature at 25°C. Finally, these effective components were separated clearly and respectively in 28 min, the linear ranges of orientin, isoorientin, vitexin, isovitexin,chlorogenic acid, caffeic acid and ferulic acid were 0.093 to 0.623 μg (r i¼ 0.9994), 0.058 to 0.385 μg (r i¼ 0.9994), 0.045 to 0.301 μg (r i¼ 0.9987), 0.041 to 0.272 μg (r i¼ 0.9992), 0.059 to 0.396 μg (r i¼ 0.9997), 0.046 to 0.312 μg (r i¼ 0.9992), 0.103 to 0.684 μg (r i¼ 0.9983), respectively; The average recoveries (n = 3) were 98.75, 98.34, 98.32, 99.70, 98.61, 98.20 and 99.31%, respectively. The validated method is simple, accurate and can be widely applied to quantification of the four flavonoids and three phenolic acid compounds in 9 different cultivars of P. pubescens.

	 

	Key words: Reversed phase high performance liquid chromatography (RP-HPLC), orientin, isoorientin, vitexin, isovitexin, chlorogenic acid, caffeic acid, ferulic acid.

https://www.academicjournals.org/article/article1380542750_Jin et al.pdf

Simultaneous determination of seven effective constituents in the leaves of bamboo by reversed phase high performance liquid chromatography (RP-HPLC)

Background: A high-performance liquid chromatography fingerprint of different variants of Phyllostachys pubescens was developed for the source discrimination and quality control of Phyllostachys pubescens medicines produced in Zhejiang Province, China. Materials and Methods: Samples of Phyllostachys pubescens collected from nine cultivars in Zhejiang Province were used to establish the fingerprint. Taking the chromatographic peak (isoorientin) as the reference peak, the chromatographic column was Sunfire C 18 ODS (250 mm×4.6 mm, 5 ΅m) at a column temperature of 25°C. The mobile phase was acetonitrile 0.8% acetic acid water solution (in a gradient elution mode) at a flow rate of 1 ml/min. The detection wavelength was 330 nm. Results: 20 common peaks were established in the chromatographic fingerprints of Phyllostachys pubescens. And then by comparing the UV and standard substance with those of the authentic standards and literature, eight main peaks in the fingerprints were identified. Data of nine cultivars were evaluated statistically using similarity analysis, hierarchical cluster analysis (HCA) in order to establish a similarity standard of fingerprint for quality control of Phyllostachys pubescens, then to classify the samples. The similarity indexes were all above 0.95 between reference chromatogram and each sample's chromatogram. Conclusion: in this study, the methods established are reliable, and could be used to evaluate the quality and to identify the species of Phyllostachys pubescens in the future.

A novel high-performance liquid chromatography fingerprint approach to discriminate Phyllostachys pubescens from China.

Phytoestrogens have been shown to affect the reproductive hormone levels in both humans and animals. As the main category of phytoestrogens, total flavonoids have a particularly important impact on female animals. To investigate the potential relationship between the total flavonoids in bamboo and the reproductive hormones in female giant pandas, urinary samples and dietary bamboo samples were collected from three main breeding locations (Beijing, Shaanxi and Sichuan). The chemical constituents of the total flavonoids in the bamboo were analysed and quantified using high-performance liquid chromatography coupled with a diode array detector (HPLC-DAD). Estradiol (E2), progestin (P), testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) were measured via radioimmunoassay (RIA). The results revealed that the total flavonoids in the bamboo from Sichuan were significantly higher than those in the bamboo from Beijing and Shaanxi, and the concentration in bamboo from Shaanxi was higher than that from Beijing (P < 0.05). The urinary E2, P, T, FSH and LH levels in pandas from Beijing were significantly lower than those in pandas from Sichuan and Shaanxi (P < 0.05). The concentrations of six reproductive hormones were positively associated with the total flavonoid contents in bamboo. In addition, the birth rate of pandas in Sichuan was significantly higher than the birth rate of pandas in Beijing and Shaanxi (P < 0.05). Thus, the flavonoids of bamboo may be related to reproduction and giant pandas might retain a sensitive adaptation to phytoestrogens from bamboo. The total flavonoids of bamboo may play a distinct role in the reproductive success of giant pandas.

Total flavonoid contents in bamboo diets and reproductive hormones in captive pandas: exploring the potential effects on the female giant panda (Ailuropoda melanoleuca).

AIM: To determine the contents of orientin,isoorientin,isovitexin in Bamboo Leaf from different sources. METHODS : Orientin,isoorientin,isovitexin were determined by HPLC. The mobile phase was MeOH-H_2O-HAc (35∶65∶1). The detective wavelength was at 340nm. RESULTS : The highest content of three favonoids was 0.89% and the lowest content was 0.07% from different sources. CONCLUSION : This method is simple,quick and accurate for determination of the three favonoids in Bamboo Leaf from different sources.

Shou Dian

Papers

Determination of orientin,isoorientin,isovitexin in Bamboo Leaf from different sources by HPLC