Butenolides, triterpenoids and phenylethanoid glycosides from Plantago depressa
Graphical abstract
Twenty-nine compounds including four new ones of two butenolides, a triterpenoid and a phenylethanoid glycoside, were isolated from Plantago depressa. Selective compounds showed anti-inflammatory and antiradical activities.
Introduction
Plantago depressa Willd. is an herbal plant commonly found in Asia; both its seeds and the plant as a whole are used in China for traditional therapies, as they have a variety of medicinal properties, such as clearing internal heat and eliminating phlegm (Flora of China Editorial Committee of Chinese Academy of Sciences, 2002; National Pharmacopoeia Committee, 2015). P. depressa is rich in phenylethanoid glucosides (Yan et al., 2009; Feng et al., 2017), iridoid glucosides (Zhang et al., 1996; Sun et al., 2010) and polysaccharides (Olennikov et al., 2011), according to published reports. Our preliminary chemical investigation has revealed the presence of lipid constituents in the ethanolic extract of this plant, and a subsequent fractionation of the ethyl acetate sub-extract returned 19 fatty acid derivatives (Song et al., 2018). Apart from the abovementioned lipid molecules, an intensive study on the remaining fractions led to the separation and identification of two new butenolides (1 and 2), a new arborinane triterpenoid (3) and 13 known triterpenoid analogues (5–17) (Fig. 1). Additionally, the polar constituents in the n-BuOH partition were further investigated, and 13 phenylethanoid glycosides, including one new glycoside (4) and 12 known structurally related glycosides (18–29) (Fig. 1), were obtained. The structures of these compounds were elucidated by comprehensive spectroscopic analyses, and the absolute configuration of the sugar moiety in 4 was determined by chiral HPLC comparison of its hydrolysis derivatives with prepared standard samples. Some compounds showed anti-inflammatory and antiradical properties. Herein, this paper describes the isolation, structure characterization and biological evaluation of these natural products.
Section snippets
Results and discussion
Compound 1 was assigned the molecular formula of C18H30O5 by (+)-HR-ESIMS analysis at m/z 349.1983 ([M + Na]+, calcd 349.1985), indicating four degrees of unsaturation. The 1H NMR data (Table 1) revealed the presence of a methoxyl [δH 3.67 (s)], two methyl [δH 1.82 (s), 1.94 (s)], and ten methylene [δH 1.16 (1H, m), 1.32 (1H, m), 1.22–1.35 (12H, m), 1.61 (2H, m), 1.75 (1H, m), 1.97 (1H, m), 2.30 (2H, t, J = 7.5 Hz)] groups. The 13C NMR data (Table 1) showed signals of two carbonyl (δC 174.6,
General experimental procedures
IR spectra were recorded on an FT-IR VERTEX 70 instrument (Bruker BioSpin AG, Fremont, USA). Optical rotations were measured on a Rudolph VI polarimeter (Rudolph Research Analytical, Hackettstown, NJ, USA) with a 10 cm length cell. NMR experiments were recorded on a Bruker Avance DRX600 spectrometer (Bruker BioSpin AG, Fallanden, Switzerland) and referenced to residual solvent peaks (CD3OD: δH 3.31, δC 49.00; CDCl3: δH 7.26, δC 77.16). ESIMS analyses were carried out on an Agilent 1260–6460
Conflict of interest
The authors declare no conflict of interest.
Acknowledgements
Financial support from the Natural Science Foundation of Shandong Province (No. JQ201721), the Young Taishan Scholars Program (No. tsqn20161037) and Shandong Talents Team Cultivation Plan of University Preponderant Discipline (No. 10027) are greatly acknowledged. We also thank Prof. Jie Zhou for the identification of the plant materials and Elsevier Webshop for the language editing service.
References (30)
- et al.
Triterpenes from Licania licaniaeflora
Fitoterapia
(2001) - et al.
Phenylethanoid glycosides from Plantago asiatica
Phytochemistry
(1991) - et al.
Nine phenethyl alcohol glycosides from Stachys sieboldii
Phytochemistry
(1991) - et al.
Phenolic compounds from Plantago asiatica
Phytochemistry
(1990) - et al.
Hydroxycinnamic acid esters of phenethylalcohol glycosides from Rehmannia glutinosa var. Purpurea
Phytochemistry
(1989) - et al.
Phenolic bisabolane sesquiterpenoids from a Thai mangrove endophytic fungus, Aspergillus sp. xy02
Fitoterapia
(2018) - et al.
Phenylethanoid and aliphatic alcohol glycosides from Acanthus ilicifolius
Phytochemistry
(2003) - et al.
In vitro antiprotozoal activity of triterpenoid constituents of Kleinia odora growing in Saudi Arabia
Molecules
(2013) - et al.
Biologically active arborinane-type triterpenoids and anthraquinones from Rubia yunnanensis
J. Nat. Prod.
(2011) - et al.
Study on separation and purification of phenylethanoid glycosides from Plantago herba by macroporous resin
Chin. J. Tradit. Chin. Med. Pharm.
(2017)
The Flora of China
New arborane type triterpenoids from Rubia cordifolia var. pratensis and R. oncotricha
Chem. Pharm. Bull.
Triterpene acids from the leaves of Planchonella duclitan (blanco) bakhuizan
J. Chin. Chem. Soc.
A new 2,3-dimethyl butenolide from the brittle star Ophiomastix mixta
Chem. Pharm. Bull.
New glycosides from Cistanche salsa
Helv. Chim. Acta
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These authors contributed equally.