New iridoid glycosides from Viburnum punctatum

Iridoid Constituents of Viburnum brachybotryum

“…The planar structure of 2 was fully characterized by 2D NMR spectroscopic data analysis (Figure S1, Supporting Information). Similarly, the identical J 1,9 (5.2 Hz) and J 5,9 (8.1 Hz) values of 2 with reported iridoids 5,8,10,30,35 implied an αorientation for H-1 and β-orientations for H-5 and H-9, which was supported by the ROESY correlations of H-1/H-9 and H-5/H-9 (Figure S1, Supporting Information). Additionally, the ROESY spectrum revealed strong cross peaks of H-1/H-10b and H-9/−OCH 2 CH 3 , confirming the α-orientation of H 2 -10 and the β-orientation of the OEt-8 group.…”

“…A comprehensive 2D NMR spectroscopic data analysis (Figure S2, Supporting Information) revealed 3 to have the same planar structure as that of 1, suggesting the two compounds to be isomeric. A βcis-fused cyclopentanopyran ring system and an α-oriented H-1 were also deduced by the similar chemical shifts and coupling constants of the corresponding protons 5,8,10,30,35 and by the ROESY correlations of H-1/H-9 and H-5/H-9 (Figure S2, Supporting Information). Different from those of 1 and 2, the ROESY experiment of 3 showed cross peaks of H-5/H-10a and H-9/H-10b, which suggested the β-orientation of H 2 -10.…”

“…The IR spectrum revealed the presence of hydroxy (3466 cm –1 ) and carbonyl groups (1744 cm –1 ). The 1 H and 13 C NMR data (Tables and ) with the aid of the HSQC spectrum displayed the presence of a keto carbonyl (δ C 215.8, C-7), an enol ether moiety [δ H 6.47 (s), δ C 142.1, CH-3 and δ C 111.3, C-4], a hemiacetal methine [δ H 6.34 (d, J = 3.4 Hz), δ C 87.5, CH-1], an oxygenated quaternary carbon (δ C 78.0, C-8), two oxygenated methylenes [δ H 3.82 (d, J = 12.3 Hz) and 3.78 (d, J = 12.3 Hz), δ C 63.4, CH 2 -10; δ H 4.68 (d, J = 12.5 Hz) and 4.43 (d, J = 12.5 Hz), δ C 63.7, CH 2 -11], two aliphatic methines [δ H 3.20 (ddd, J = 9.5, 8.6, 4.5 Hz), δ C 26.0, CH-5 and δ H 2.70 (dd, J = 8.6, 3.4 Hz), δ C 45.6, CH-9], and an aliphatic methylene [δ H 2.76 (dd, J = 19.5, 9.5 Hz) and 2.62 (dd, J = 19.5, 4.5 Hz), δ C 38.8, CH 2 -6], suggesting that 1 is a typical iridoid of the genus Viburnum . − The iridoid skeleton was then confirmed by 2D NMR spectroscopic data analysis (Figure ). The 1 H– 1 H COSY correlations of H-1/H-9, H-9/H-5, and H-5/H 2 -6 indicated the connections of these proton-linked carbons as shown in Figure .…”

“…The genus Viburnum belongs to the Adoxaceae (formerly Caprifoliaceae) family and consists of about 200 species mostly distributed in temperate and subtropical regions of Asia and South America . Many species of Viburnum have been used as folk medicines all over the world for the treatment of coughs, diarrhea, rheumatic arthralgia, allergic dermatitis tumefaction, kidney cramps, and bone fractures. − Previous investigations on Viburnum species have reported a large number of natural products containing iridoids, − vibsane-type diterpenoids, ,− triterpenoids, , and lignans and neolignans, − with a wide range of biological activities such as antidiabetic, ,, anti-inflammatory, ,, antioxidant, , estrogen inhibitory, neurite outgrowth-promoting, ,, cytotoxic, − ,, and HSP90 inhibitory ,, effects, which have led to a further design, synthesis, and cancer-related activity study …”

Recent Advance on Chemistry and Bioactivities of Secondary Metabolites from Viburnum Plants: An Update

“…ceanothoids , and 172 can inhibit estrogen biosynthesis [47] . Three new valeriana‐type iridoids with disaccharides, namely, viburpunosides A–C ( 173 – 175 ) were separated from Viburnum punctatum [48] . In addition to 178 discovered from V. ternatum , [16] another two iridoids ( 176 and 177 ) with the dioxatricyclodecane skeleton were obtained from the leaves of Viburnum formosanum subsp.…”