Medicinal Flowers. XXXX.¹⁾ Structures of Dihydroisocoumarin Glycosides and Inhibitory Effects on Aldose Reducatase from the Flowers of <i>Hydrangea macrophylla</i> var. <i>thunbergii</i>

Abstract

Key words florahydroside; Hydrangea macrophylla var. thunbergii; medicinal flower; dihydroisocoumarin glycoside; aldose reductase; acylated quinic acid analogThe Saxifragaceae plant, Hydrangea (H.) macrophylla Seringe var. thunbergii Makino, is native to Japan. The processed leaves of this plant (Hydrangea Dulcis Folium) are currently used as a natural medicine for an oral refrigerant and as a sweetener for diabetic patients. In addition, these preparations are listed in the Japanese Pharmacopoeia. Previously, we reported the isolation and structure determination of many chemical constituents with anti-diabetic, anti-allergic, and anti-bacterial activities from the processed leaves and the dried leaves of this plant.2-6) However, a full chemical analysis of the flowers from this plant has not yet been performed. In the course of our chemical and pharmacological studies on Hydrangea plants [2][3][4][5][6][7][8] and medicinal flowers, [9][10][11][12][13][14] we recently reported the isolation and structure elucidation of secoiridoid glycosides named hydrangeamines A and B with a pyridine ring from the flowers of H. macrophylla var. thunbergii cultivated in Nagano prefecture, Japan.15) As a continuing study, six dihydroisocoumarin glycosides, florahydrosides I (1) and II (2), thunberginol (5), and thunberginol D 3′-O-β-dglucopyranoside (6), were isolated from the flowers of H. macrophylla var. thunbergii together with 20 known compounds including five acylated quinic acid analogs. Furthermore, the inhibitory effects of the isolated compounds and its related compounds on aldose reductase were investigated. This paper deals with the structure elucidation of the new dihydroisocoumarin glycosides (1-6) and the inhibitory effects of the constituents and their related compounds, acylated quinic acid analogs, on aldose reductase.A methanol (MeOH) extract (32.2% from the flowers of H. macrophylla var. thunbergii cultivated in Nagano province) was partitioned between EtOAc-H 2 O (1 : 1) to furnish an EtOAc-soluble fraction (8.8%) and an aqueous layer. The aqueous layer was further extracted with 1-butanol

Highly sensitive determination of new metabolite in rat plasma after oral administration of swertiamarin by liquid chromatography/time of flight mass spectrometry following picolinoyl derivatization

“…Although belonging to the dihydroisocoumarin, the biological activity of HMIO has rarely been reported. It has been reported that dihydroisocoumarins show very important bioactivities, such as selective inhibition of aromatase (Endringer et al ., ), anticancer activity (Higgins et al ., ) and inhibitory effects on aldose reducatase (Liu et al ., ). It is probable that HMIO also plays an important role for the pharmacological effects of STM in vivo .…”

New analytical method for the study of metabolism of swertiamarin in rats after oral administration by UPLC‐TOF‐MS following DNPH derivatization

“…Although it belongs to the dihydroisocoumarins, the biological activity of ECR is rarely reported. It has been reported that dihydroisocoumarins show very important bioactivities, such as selective inhibition of aromatase (Denise et al, 2008), anticancer (Higgins et al, 2009) and inhibitory effects on aldose reductase (Liu et al, 2013). It is probable that ECR also plays an important role in the pharmacological effects of STM in vivo.…”

Cataract Preventive Role of Isolated Phytoconstituents: Findings from a Decade of Research

“…Caffeoylquinic acid analog, 4,5-Di- O -trans-caffeoyl- d -quinic acid isolated from Hydrangea macrophylla var. thunbergii (bigleaf hydrangea) and Ilex paraguariensis (Yerba mate) showed the strongest inhibitory activity against RLAR at IC 50 value of 0.29 µM [ 55 ]. Inhibitory effect of quinic acid with two caffeoyl groups assisted the potency.…”