Phytochemical Profiling and Evaluation of Pharmacological Activities of Hypericum scabrum L.

Lan Jiang,Khayrulla Bobakulov,Sodik Numonov,Haiqing Zhao,Haji Aisa,Muhammad Qureshi

doi:10.3390/molecules200611257

Abstract

Phytochemical investigations of ethyl acetate-soluble part of the aerial part of Hypericum scabrum L. delivered eight pure phenolic compounds 1–8. The pure compounds were identified through physico-chemical, NMR (1D, 2D) and mass spectrometric studies as: 3-8′′-bisapigenin (1), quercetin (2), quercetin-3-O-α-l-arabinofuranoside (3), quercetin-3-O-α-l-rhamnoside (4), quercetin-3-O-β-d-glucopyranoside (5), quercetin-3-O-β-d-galactopyranoside (6), (−)-epicatechin (7), (+)-catechin (8). Total polyphenolic compounds and total flavonoids contents were determined in the extract as 0.107 mg∙mg−1 and 0.023 mg∙mg−1 of the dried extract, respectively. Antioxidant activity using DPPH free radical scavenging assay delivered very strong activity for compounds 2 and 5, 6 and crude extract 10. Protein tyrosine phosphatase 1B (PTP-1B) inhibition experiment of isolated compounds and crude extracts resulted in significant inhibition activity for samples 2, 7a, 8a, 11 and 12 with IC50 values ranging from 1.57 to 2.91 µM. Antimicrobial activity of the pure compounds and extracts produced average results against Staphylococcus aureus, Escherichia coli and Candida albicans strains. From our literature survey, it appears that all pure compounds except 2 were isolated and reported for the first time in H. scabrum.

Highlights

Medicinal plants have a long history of use in traditional systems of medicines, and are considered the primary sources of important medicines [1]
From our literature survey it appears that all the pure compounds except 2 were isolated and reported for the first time in H. scabrum
The study confirmed the presence of bioactive compounds like quercetin glycosides, bisapigenin, catechin and epicatechin in the aerial part of H. scabrum in sufficient amounts to be isolated employing routinely applied chromatographic procedures

Summary

Introduction

Medicinal plants have a long history of use in traditional systems of medicines, and are considered the primary sources of important medicines [1]. Flavonoids belong to a group of natural substances with variable phenolic structures and are found in fruit, vegetables, grains, bark, roots, stems, flowers, tea, and wine [2,3] These natural products were known for their beneficial effects for health as crude plant material or plant extracts long before flavonoids were isolated in pure forms as effective compounds for various pharmacological activities such as antioxidant, antidiabetic, antimicrobial etc. Herbs, vegetables, cereals, nuts, and other plant materials rich in phenolic compounds are increasingly of interest in the food industry [6] They are the group of compounds which received considerable attention from the researchers as depicted from the scientific literature. They are present in plants as glycosides but can be isolated in free aglycon form [7,8]

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