Hypofolins A – L, ent‐Labdane Diterpenoids from the Roots of Hypoestes phyllostachya ‘Pink Splash’

Abstract

Twelve new ent-labdane diterpenoids, hypofolins A - F (1 - 6) and hypofolins G - L (7a/7b, 8a/8b, and 9a/9b), were isolated from the roots of Hypoestes phyllostachya 'Pink Splash'. Their structures were elucidated by extensive 1D- and 2D-NMR spectroscopic and HR-MS data. The absolute configurations of 1, 2, 5, and 7a/7b were determined by single crystal X-ray diffraction and ECD analysis, as well as chemical transformations. Compounds 7a/7b, 8a/8b, and 9a/9b were isolated as three pairs of interconverting mixture of two isomers between ketone and hemiketal types. Compound 1 showed weak cytotoxicity against SMMC-7721 cell line with IC value of 31.40 μm.

Asymmetric syntheses of ent-pimarane diterpenoids

“…This ketal tautomerism is also observed in structurally similar ent -labdane diterpenoids, hypofolins I and J. 19…”

Hypoestins A–D: highly modified fusicoccane diterpenoids with promising Cav3.1 calcium channel inhibitory activity from Hypoestes purpurea

“…7,[19][20][21][22][23][24][25] However, the chemical constituents of H. purpurea were barely investigated, and only a few labdane diterpenoids, triterpenoids, and lignans were reported. 21 As part of our ongoing efforts to discover bioactive ingredients from the genus Hypoestes, 19,26 four highly modified fusicoccane diterpenoids with two unreported carbon scaffolds, hypoestins A-D (1-4), were isolated from the aerial parts of H. purpurea, as well as two previously undescribed ones (Fig. 1).…”

Hypopurolides A – G, Labdane Diterpenoids from Hypoestes purpurea and Their Nitric Oxide Inhibitory Activity

“…Among them, hypopurin A, a furanolabdane diterpenoid, was found to exhibit moderate cytotoxicity against epidermoid carcinoma KB cell lines with an IC 50 value of 9.4 μM [3] . As part of a research program to discovery bioactive compounds from Hypoestes species, [2,17−19] chemical ingredients from the aerial part of H. purpurea were investigated, resulting in the discovery of seven new labdane‐type diterpenoids, hypopurolides A−G ( 1 – 7 ) ( Figure 1), and one known analog, hypopurin D ( 8 ) [3] . Herein, we present the isolation, structure characterization, and biological screening of 1–8 .…”