Chromatographic analysis of salicylic compounds in different species of the genus Salix

Abstract

The separation of nine phenol glycosides--salicin, salicortin, 2'-acetylsalicortin, populin, tremulacin, salidroside, triandrin, picein and helicin--by normal phase (NP), reversed phase (RP) HPLC techniques and a coupling of NP and RP monolithic silica columns was studied. Among the above nine compounds only five--salicin, populin, tremulacin, salidroside and triandrin--were resolved in an NP system with a mobile phase comprising hexane/isopropanol/methanol (87:12:1, v/v/v). Optimized separation was performed with two coupled monolithic silica columns of different polarity (bare silica and RP-18). The method was applied to verify the presence of salicylic compounds and other phenolic derivatives in the bark of six species from the genus Salix, namely S. purpurea, S. daphnoides clone 1095, S. alba clone 1100, S. triandra, S. viminalis, and S. herbacea. Gradient elution with a mobile phase composed of acetonitrile and water containing 0.05% of trifluoroacetic acid, with increasing acetonitrile concentration from 3% to 48%, was chosen as optimal. For the selective detection of the salicylic compounds, an evaporative light scattering detector was employed along with a UV detector. The differences in the composition of phenols in the different plant materials were confirmed. Additionally, it must be emphasized that for the first time the presence of 2'-acetylsalicortin was revealed in S. alba clone 1100. Furthermore, an SPE-HPLC method was developed for the rapid analysis of the salicin content, analyzed as free and total fraction, in willow barks. The determined concentrations of total salicin varied from 25.4 mg/g in S. alba clone 1100 to 96.47 mg/g in S. daphnoides clone 1095.

Comprehensive analysis of commercial willow bark extracts by new technology platform: Combined use of metabolomics, high-performance liquid chromatography–solid-phase extraction–nuclear magnetic resonance spectroscopy and high-resolution radical scavenging assay

“…The HPLC method described above was used for the quantification of salicin and validated for precision (intra-day and inter-day repeatability tests), accuracy, linearity, and sensitivity (limit of detection, LOD, and limit of quantitation, LOQ) [11]. Thus, intra-day and inter-day reproducibility tests were performed by quantitative analysis of three concentrations of salicin (0.5, 1.0 and 2.0 mg/mL) on three consecutive days.…”

“…Thus, 200 L of 0.1 M NaOH was added directly to the HPLC vial and the mixture were heated on a water bath at 60 • C for 1.5 h. The sample was neutralized with 20 L of 1 M HCl and subsequently analyzed by HPLC. The method has been adapted after [11]. Injection volumes were 20 L for samples containing herbal preparations as well as for salicin standard solutions.…”

“…Several studies have focused on phytochemical investigation of Salix species used for preparing the final willow bark products, and, e.g., Salix daphnoides, Salix pentadra, Salix purpurea, Salix alba, and Salix fragilis have been investigated for their content of phenolic glycosides [9][10][11]. In addition to salicylates, flavonoids and condensed tannins constitute the major groups of secondary metabolites in Salix species, and these compounds are believed to contribute to the analgesic and anti-inflammatory effect of willow bark [12,13].…”

Biodiversity of Salix spp. Honeydew and Nectar Honeys Determined by RP‐HPLC and Evaluation of Their Antioxidant Capacity

“…Salicylic acid (5) is a typical constituent of Salix spp. bark [24], so its presence in willow honeydew can be explained with the activity of sap-sucking insects that extract this type of plant biochemical compounds when phloem vessels are punctured. Salicylic acid (5) was detected in honeydew (3.6 -4.9%) and in nectar (0.2 -0.8%) willow honey volatiles [5] [6], and in several other honeys (e.g., chestnut, eucalyptus, fir, oak) ranging from 0.249 to 7.059 mg/kg [25] [26].…”

RAPD Markers Reveal Genetic Diversity inSalix purpureaL.

“…Salicylic glycosides present in the bark have an analgesic, antipyretic, and anti-infl ammatory eff ect (Bisset and Wichtl, 2001). In addition to diff erences in the salicylic glycoside content of bark between various species (Pobłocka-Olech et al, 2007), published sources indicate that this attribute also varies signifi cantly within each species (Sulima et al, 2006). In addition to diff erences in the salicylic glycoside content of bark between various species (Pobłocka-Olech et al, 2007), published sources indicate that this attribute also varies signifi cantly within each species (Sulima et al, 2006).…”