24-meth-Development of Chromatographic Fingerprint Profile and Multi-elemental Analysis of Datura metel L.

Background: The Solanaceae family member Datura metel L. has been related to therapeutic benefits. The plant is widely used in Ayurveda and Siddha systems of Indian medicines. Objectives: Present study was focused to understand the phytochemical and multi elemental composition of D. metel whole plant. Materials and Methods: The whole plant of D. metel was collected, shade dried, powdered and subjected to analysis of physico-chemical parameters, thin layer chromatography, high performance thin layer chromatographic finger print profilings (HPTLC), high pressure liquid chromatographic profile at four wavelengths, X-ray fluorescence, energy dispersive X-ray analysis, X-ray photoelectron spectrometer, powder X-ray diffractometer and inductively coupled plasma optical emission spectrometer. Results: In HPTLC, 7 spots under 254 nm, 10 spots under 366 nm and 11 spots after derivatization with vanillin sulphuric acid reagent appeared. In HPLC, 9 peaks at 230 nm, 11 peaks at 254 nm, 5 peaks at 286 nm and 7 peaks at 366 nm separated. Presence of 17 elements such as copper, cobalt, nickel, manganese, zinc, iron, sodium, potassium, calcium, magnesium, phosphorus, aluminium, chlorine, carbon, oxygen, sulphur and silicon were identified. Conclusion: The elements K, Mg, Ca, Si, S and Fe play vital role on human health. Chlorine, silicon, sulfur and silica are first time identified which have significant biological functions.


Plant Material
The whole plant of D. metel (DM) was collected from natural habitat in Kumarapalayam region of Namakkal District, Tamil Nadu, India.It was authenticated by the Pharmacognosist of this Institute, dried at room temperature and powdered.

Physicochemical Analysis
The plant was analyzed for moisture content in terms of loss on drying, inorganic content in terms of total ash, water soluble ash, silicious matter in terms of acid insoluble ash, extractive values in water and alcohol as per WHO methods.

TLC/HPTLC analysis
A high performance thin layer chromatography (HPTLC) system for detection of separation; Linomat IV applicator for extract application; twin chamber for developing the TLC plate; scanner 030618 attached with WINCATS software for qualitative and quantitative scanning; visualizer for photo documentation at dual wavelengths 254 and 366 nm; in visible lights after derivatization with vanillin sulfuric acid reagent and heating till color development are from CAMAG, Muttenz, Switzerland.Analytical reagent grade solvents toluene, ethyl acetate, methanol and formic acid with 99.8% purity were obtained from E. Merck chemicals.Plant powder (100 mg) was extracted with 100 ml aqueous methanol by sonicating for 5 min, filtered using Whatman no.1 filter paper, concentrated to 1 ml using Rotavapor R-300, and used as test solution for HPTLC analysis.The mobile phases for methanol extract, ethyl acetate: toluene: formic acid (2:5:0.5,v/v/v) was finalized.Sample solution (10 μl) of was loaded as band having length of 8 mm on 4×10 Silica gel 60F 254 TLC plate using auto sampler.The sample applied plate was positioned in a presaturated twin trough chamber and the plate was developed in the mobile phase up to 90 mm.After evaporation of solvents from plate on air, the plate was viewed under photo documentation chamber at UV 254 and 366 nm and their images were captured.Vanillin sulfuric acid reagent was sprayed over the developed plate and heated at 100°C on a plate heater for developing the colored spots.Scanning of the plate was done in duel at 254 and 366 nm and after derivatization at 520 nm to record densitogram with finger prints and peak tables.

DISCUSSION
For the quantification of atropine and scopolamine from D. metel by HPLC-MS has been reported [59] but TLC or HPTLC date for the identification of the plant is not available.The correlation of elemental composition of D. metel in ICP-OES and XRF techniques with respect to Mn, Ca, Fe, K and Zn is given in Figure 7.
The disparity between XRF, EDAX, PXRD and ICP-OES values is due to the fact that range of elements which are detected by ICP-OES is wide; [60] EDAX, XRF, PXRD are surface elemental analytical technique which give different elemental composition in different locations of the sample; ICP-OES measures the content of elements in the whole sample. [60]The wide variation in elemental composition obtained using XRF, ICP-OES and EDAX has also been reported during examination of geochemical sample, [61] soil sample, [62,63] and municipal landfill. [64]espite the above facts, the ICP-OES data and some of other data are common in the detection of elements such as calcium, chlorine (as chloride in PXRD), potassium, silica and sodium.The content of Al was almost same in EDAX, XRF and ICP-OES but not identified in XPS and PXRD.The content of Ca was comparable in EDX, PXRD and ICP-OES but it was very high in XRF other techniques.Fe was not detected in XPS and PXRD.The content of K in almost double time higher in other spectral methods than ICP-OES.But the content of Na and Si, results of EDAX and XRF were comparable and similarly ICP-OES with PXRD.However, Co, Cu and S were not identified in any of the spectral technique except ICP-OES.The lower detection limits and accuracy of ICP-OES is better when compared to the XRF and SEM-EDX, [65] the multi elemental composition of D. metel is taken into consideration.D. metel plant has a high concentration of K which is vital for maintenance of cardiarhythm, [66] Mg which is essential for cardiovascular health, [67] Ca which is an important mineral normal functioning of human body, [68] silica which is indispensable for liver health, [69] permissible level of S which protects the cells in the body from heavy radiation and pollution, [70] and Fe which is important nutrient for impairing immune system. [71]rom the literature, the presence of copper, cobalt, nickel, manganese, zinc, iron, sodium, potassium, calcium, magnesium, phosphorous and aluminum have been reported in D. metel. [72]

CONCLUSION
In the presence study, in addition to earlier reported elements, chlorine, silicon, sulfur and silica are reported which also find biological applications.In addition, the TLC photo documentations would serve as a new scale for the authentication of the plant along with the pharmacopoeial standards.

Figure 1 :
Figure 1: TLC fingerprint profile at 254 nm, 366 nm and 520 nm and peak area.