Crataegus turcicus is a plant endemic to Türkiye. For the first time, this study aimed to comparatively assess its flower-bearing branches, leaves, and fruits with other well-known Crataegus species (C. monogyna, C. pentagyna, and C. orientalis) in terms of chemical composition and bioactivity studies to evaluate its potential use as a food supplement. Firstly, the contents of total phenolics (TPC), flavonoids (TFC), proanthocyanidin (TPAC), and anthocyanin (TAC) in different plant parts of Crataegus species were evaluated. The highest TPAC was found in the hydroalcoholic extract of C. turcicus flower-bearing branches. Moreover, all plant parts had comparatively higher amounts of TPC, TFC, and TAC compared to other Crataegus species. The chemical screening by high-performance thin-layer chromatography (HPTLC) resulted that C. turcicus parts were rich with chlorogenic acid, neochlorogenic acid, quercetin and vitexin derivatives, epicatechin, procyanidin, etc., and their quantities were evaluated by high-performance liquid chromatography (HPLC). In terms of several in vitro antioxidant activity outcomes, the flower-bearing branches of C. turcicus showed the highest antioxidant activity by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) test among the assessed antioxidant assays. Additionally, hydroalcoholic extracts of C. turcicus significantly decreased LPS-induced nitric oxide, tumor necrosis factor-alpha, and interleukin-6 production more potently than indomethacin (positive control). In addition to its remarkable anti-inflammatory activity, C. turcicus showed analgesic activity by reducing prostaglandin E₂ levels.

Bee pollen, known as a ‘life-giving dust’, is a product of honeybees using flower pollen grains and combining them with their saliva secretions. Thus, flower pollen could be an indicator of the bee pollen botanical source. Identification of bee pollen sources is a highly crucial process for the evaluation of its health benefits, as chemical composition is directly related to its pharmacological activity. In this study, the chemical profiles, contents of phenolic marker compounds and pharmacological activities of Hedera helix L. (ivy) bee pollen samples from Türkiye and Slovenia, as well as ivy flower pollen grains, were compared. High-performance thin-layer chromatography (HPTLC) analyses revealed that pollen samples, regardless of where they were collected, have similar chemical profiles due to the fact that they have the same botanical origins. Marker compounds afzelin, platanoside and quercetin-3-O-β-glucopyranosyl-(1→2)-β-galactopyranoside, common to both bee pollen and flower pollen, were isolated from bee pollen, and their structures were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS). These three compounds, as well as chlorogenic acid and 3,5-dicaffeoylquinic acid (found in flower pollen), were quantified using high-performance liquid chromatography (HPLC) analyses. In vitro tests and effect-directed analyses were used to evaluate the xanthine oxidase inhibition and antioxidant activity of the marker compounds and extracts from flower pollen and bee pollen. This is the first report comparing chemical profiles and related bioactivities of the flower pollen and bee pollen of the same botanical origin, as well as the first report of the chemical profile and related bioactivities of ivy flower pollen.

Qualitative and quantitative differences in the chemical composition between bee pollen originated from Castanea sativa (Türkiye and Slovenia), Salix spp. (Türkiye and Slovenia), and Quercus spp. (Türkiye) and androecia of Castanea sativa, Salix alba, and Quercus pubescens (apetalous trees) were evaluated for the first time by new high-performance thin-layer chromatography (HPTLC) and ultra-performance liquid chromatography (UPLC) methods using marker compounds. N¹,N⁵,N¹⁰-tricaffeoylspermidine was isolated, and its structure was elucidated by nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS). It was the main and the marker compound common to bee pollen (≈3–41 mg/g) and androecia (≈3–6 mg/g) samples. To the best of our knowledge, this is the first report of the identification of N¹,N⁵,N¹⁰-tricaffeoylspermidine in bee pollen originated from Salix spp. and androecia of C. sativa, S. alba, and Q. pubescens. The botanical origins of bee pollen were determined via phytochemical profiling using HPTLC-image analyses showing that bee pollen from the same botanical source had almost identical profiles regardless of collection location, geographical differences, and the bee race. In vitro tests and HPTLC-effect-directed analyses (EDAs) were performed to assess antioxidant and xanthine oxidase (XO) inhibitory activities of bee pollen, androecia, and N¹,N⁵,N¹⁰-tricaffeoylspermidine. HPTLC-EDA combined with image analyses was used for comparing the activities of bee pollen, androecia, N¹,N⁵,N¹⁰-tricaffeoylspermidine, and also other marker compounds (quercetin, myricitrin, hyperoside, quercitrin, isoquercitrin, and rutin). The remarkable bioactivity of N¹,N⁵,N¹⁰-tricaffeoylspermidine was for the first time evaluated by HPTLC-EDA and in vitro tests. This is the first study performing HPTLC-XO inhibitory activity analyses on the HPTLC NH₂ F_254S plates. Further bioactivity studies on botanically and chemically well-characterized bee pollen samples are needed to aid in the use of bee pollen-containing supplements in the prevention and treatment of diseases.