Pamita Bhandari

Antioxidant activity and ultra-performance LC-electrospray ionization-quadrupole time-of-flight mass spectrometry for phenolics-based fingerprinting of Rose species: Rosa damascena, Rosa bourboniana and Rosa brunonii.

Roses are one of the most important groups of ornamental plants and their fruits and flowers are used in a wide variety of food, nutritional products and different traditional medicines. The antioxidant activity of methanolic extracts from fresh flowers of three rose species (Rosa damascena, Rosa bourboniana and Rosa brunonii) was evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical method. The ability to scavenge DPPH radical was measured by the discoloration of the solution. The methanolic extract from R. brunonii exhibited maximum free-radical-scavenging activity (64.5+/-0.38%) followed by R. bourboniana (51.8+/-0.46%) and R. damascena (43.6+/-0.25%) at 100 microg/ml. Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study phenolic composition in the methanolic extracts from the fresh flowers of rose species. The phenolic constituents were further investigated by direct infusion-ESI-QTOF-MS/MS in negative ion mode. Characteristic Electrospray ionization tandem mass spectrometry (ESI-MS/MS) spectra with other diagnostic fragment ions generated by retro Diels-Alder (RDA) fragmentation pathways were recorded for the flavonoids. Distinct similarities were observed in the relative distribution of polyphenolic compounds among the three species. The dominance of quercetin, kaempferol and their glycosides was observed in all the three species.

Simultaneous determination of sugars and picrosides in Picrorhiza species using ultrasonic extraction and high-performance liquid chromatography with evaporative light scattering detection☆

Sugars play a critical role in regulating overall cellular metabolism in high altitude growing plants. These plants are shown to have high levels of sugars to enhance their tolerance to abiotic stresses such as drought and freezing temperature. In the present study, a simple, sensitive, selective and reliable HPLC method based on ultrasonic extraction and evaporative light scattering detection (ELSD) has been developed and validated for the simultaneous determination of important sugars (xylose, xylitol, mannitol, glucose and sucrose) and picrosides (picroside-I and picroside-II) in two species Picrorhiza kurroa and P. scrophulariiflora. The analysis was carried out on a Zorbax amino column (250 mm x 4.6 mm i.d., 5 microm) with isocratic elution of acetonitrile:water (78:22, v/v). The method was validated for accuracy, precision, limit of detection and quantification according to International Conference on Harmonization (ICH) guidelines. The drift tube temperature of the ELSD system was set to 81 degrees C and nitrogen flow rate was 2.0 standard liter per minute (SLM). The regression equation revealed a good linear relationship (r(2)=0.9997+/-0.0012) within test ranges. The limit of detection and quantification for seven analytes in ELSD were less than 0.98 and 2.95 microg, respectively. The method showed good reproducibility for the quantification of seven analytes in Picrorhiza species with intra- and inter-day variation of less than 2.0%.

Reversed phase-HPLC for rapid determination of polyphenols in flowers of rose species*

A rapid, simple, sensitive, robust, and improved HPLC method was developed and validated for determination of 10 polyphenols, namely gallic acid, catechin, epicatechin, rutin, m-coumaric acid, quercitrin, myricetin, quercetin, apigenin, and kaempferol in fresh flowers of Rosa bourboniana and R. brunonii and in both fresh flowers and marc (left after industrial distillation of rose oil) of R. damascena. Six polyphenols, gallic acid, rutin, quercitrin, myricetin, quercetin, and kaempferol, were detected and quantified in all extracts. The chromatographic separation of 10 polyphenols was achieved in less than 16 min by RP-HPLC (Phenomenex, Luna C18 (2) column, 5 microm, 250 mm x 4.6 mm) using linear gradient elution of water and acetonitrile (0.02% trifluroacetic acid) with a flow rate of 1 mL/min at lambda 280 nm. Standard calibration curves were linear in the range of 0.39-500 microg/mL. Good results were achieved with respect to repeatability (RSD <3%) and recovery (98.6-100.8%). The method was validated for linearity, accuracy, repeatability, LOD, and LOQ.

HPTLC determination of swertiamarin and amarogentin in Swertia species from the western Himalayas

A high-performance thin-layer chromatographic (HPTLC) method has been established for simple and rapid quantification of two secoiridoids, swertiamarin and amarogentin, in two Swertia species. HPTLC of secoiridoids was performed on precoated silica 60 F254 plates with EtOAc–MeOH–H2O, 77 + 8 + 8 (v/v), as mobile phase. Densitometric determination of the secoiridoids was performed at λ = 235 nm in reflectance/absorbance mode. The method was validated for precision, repeatability, and accuracy. Average recovery of amarogentin and swertiamarin was 94.5 and 96.5%, respectively, showing that the reproducibility of the method was excellent. The method is simple, precise, specific, sensitive, and accurate and can be used for routine quality control of raw materials and herbal formulations.

Silica‐based monolithic column with evaporative light scattering detector for HPLC analysis of bacosides and apigenin in Bacopa monnieri

A high performance liquid chromatographic method using a silica-based monolithic column coupled with evaporative light scattering detector (HPLC-ELSD) was developed and validated for simultaneous quantification of bacosides (bacoside A, bacopaside I, bacoside A(3), bacopaside II, bacopaside X, bacopasaponin C) and apigenin in Bacopa monnieri. The chromatographic resolution was achieved on a Chromolith RP-18 (100x4.6 mm) column with acetonitrile/water (30:70) as mobile phase in isocratic elution at a flow rate of 0.7 mL/min. The drift tube temperature of the ELSD was set to 95 degrees C, and the nitrogen flow rate was 2.0 SLM (standard liter per minute). The calibration curves revealed a good linear relationship (r(2) > 0.9988) within the test ranges. The detection limits (S/N = 3) and the quantification limits (S/N = 10) for the compounds were in the range of 0.54-6.06 and 1.61-18.78 microg/mL, respectively. Satisfactory average recovery was observed in the range of 95.8-99.0%. The method showed good reproducibility for the quantification of these compounds in B. monnieri with intra- and inter-day precision of less than 0.69 and 0.67%, respectively. The validated method was successfully applied to quantify analytes in nine accessions of B. monnieri and thus provides a new basis for overall quality assessment of B. monnieri.

Evaluation of Picrorhiza kurrooa accessions for growth and quality in north western Himalayas

Different accessions of Picrorhiza kurrooa were evaluated for growth and marker compound accumulation pattern under field conditions at village Chuner, Sub Tehsil, Holi, Distt. Chamba (HP) located at an elevation of 2538 m during 2006 to 2010. Six accessions with higher Picroside content and vegetative growth were identified for further multiplication. Accession IHBT-PK-8 recorded higher leaf numbers/plant (250), length of 6th leaf (5.4 cm) stolon girth (7.5 mm) and plant spread in N-S direction (50.0 cm). Picroside content in leaf and rhizome of different accessions was determined by high-performance liquid chromatography (HPLC). It was found that leaves of P. kurrooa are good source of picrosides. Picroside-I (P-I) content in leaf was higher in IHBT-PK-2 (3.89%) followed by IHBT-PK-11 (3.72%) and IHBT-PK-21 (3.70%). Picroside -II (P-II) content in leaf was higher in IHBT-PK-5 (4.82%). P-I content in rhizomes of P. kurrooa varied from 0.20 to 4.14% and P-II varied from 0.83 to 7.29% in different accessions. Higher P-I in rhizome was found in IHBT- PK-16 (4.14%). Rhizomes showed higher amount of P- II as compared to P-I.

Dammarane triterpenoid saponins from Bacopa monnieri

Bacopa monnieri is a well-known Ayurvedic Indian medicinal plant traditionally used as a memory enhancer. Its memory-enhancing effect is mainly attributed to dammarane triterpenoid saponins. In the present study, two new dammarane-type triterpenoid saponins, bacopaside-XI (1) and bacopaside-XII (2), together with known compounds, bacopaside IV, bacopaside V, and apigenin, were isolated from the aerial parts of the B. monnieri. The structures of the new saponins were elucidated as 3-O-[α-L-arabinofuranosyl(1→3)]-6-O-sulfonyl-β-D-glucopyranosyl pseudojujubogenin (1) and 3-O-{β-D-glucopyranosyl(1→3)[α-L-arabinofuranosyl(1→2)]-β-D-glucopyranosyl}-20-O-α-L-arabinopyranosyl pseudojujubogenin (2) on the basis of extensive investigations of 1D and 2D NMR (HMQC and HMBC), ESI-QTOF-MS/MS spectroscopic methods, and chemical evidences.

Online antioxidant activity and ultra-performance LC-electrospray ionisation-quadrupole time-of-fight mass spectrometry for chemical fingerprinting of Indian polyherbal formulations

A HPLC–DAD–DPPH method was developed for evaluating the 1, 1-diphenyl-2-picryl hydrazyl free radical scavenging activity of ethylacetate extracts of different polyherbal formulations (draksarista, draksava, lohasava and arvindasava) by using RP-18e column. The ethylacetate extract from polyherbal, ‘draksarista’ exhibited maximum free radical scavenging activity (99.9 ± 0.38%) followed by draksava (99.8 ± 0.34%), lohasava (98.5 ± 0.30%) and arvindasava (42.3 ± 0.34%) at 100 μg mL− 1. Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionisation-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study chemical composition of the ethylacetate extracts of formulations. The characteristic electrospray mass ionisation reveals the dominance of polyphenols and their glycosides in the four polyherbal formulations.