Neogenkwanines A–H: daphnane-type diterpenes containing 4,7 or 4,6-ether groups from the flower bud of Daphne genkwa

Abstract

Neogenkwanines A-H (1-8), eight daphnane-type diterpenes possessing new skeletons with 4,7-or 4,6-ether group, along with seven known ones (10-16), were isolated from Daphne genkwa. Their structures and absolute configurations were established by analysis of their NMR, X-ray crystallography, CD exciton chirality data and hydrolysis experiments. In addition, an MTT assay was used to examine the growthinhibitory effects of all the new isolates on HL-60, Hep3B, and U87 cells; Compounds 3, 4 and 5 exhibited significant inhibitory effects against Hep3B cell lines with IC 50 values of 7.61, 8.16 and 8.35 µM, respectively.

Isolation, Structural Elucidation, and Anti-HIV Activity of Daphnane Diterpenoids from Daphne odora

“…Next, the NOESY correlation between H-1β/H 3 -19 supported H-2 as being in an α-orientation. This assignment was further evident from the coupling constant of J H‑2/H‑3 = 9.5 Hz, which indicated a cis relationship between H-2 and H-3 . The occurrence of a 4β,7β-epoxy moiety led to the observation of characteristic NOESY correlations between H 2 -20/H-7 and H-7/H-14, as well as the coupling constants of J H‑7/H‑8 = 3.3 Hz and J H‑8/H‑14 = 1.4 Hz, which were in good accordance with the X-ray structure data of neogenkwanine A, which has the same relative configuration .…”

Genkwadane F—I, New Daphnane‐type Diterpenes from the Flower Buds of Daphne genkwa Sieb.et Zucc. Exhibit Anti‐tumor Activities via Inducing Apoptosis

“…Daphnane‐type diterpenes exhibited a wide range of interesting biological activities such as anti‐tumor, anti‐fertility, anti‐HIV, cholesterol‐lowering, anti‐hyperglycemic and neurotrophic activities. [ 4,5,10‐12 ] In general, most of daphnane‐type diterpenes possessing a 9,13,14‐orthoester function, showed significant cytotoxicity against various types of cancer cells. [ 4,5,10,13 ]…”

“…In our previous study, several diterpenes with anti‐tumor activities have been obtained from D. genkwa . [ 12,14,15 ] As a part of continuing projects to discover potential anti‐tumor natural products from D. genkwa , eight diterpenes ( 1 — 8 ) including four new daphnane‐type diterpenes ( 1 — 4 ) were isolated (Figure 1). In the present study, we described the isolation and structural elucidation including absolute configuration, and cytotoxicity evaluations of those diterpenes.…”

Natural Products Research in China From 2015 to 2016

“…Kadcoccinone C ( 619 ) possessed an unprecedented 6/6/9-fused carbocyclic core containing a rare oxabicyclo[4.3.1]decane system, while kadcoccinones D ( 620 ) and E ( 621 ) were two novel 18(13→12)-abeo-26-norlanostane triterpenoids (Hu et al, 2015 ). Neogenkwanines A–H ( 622 - 629 ), daphnane-type diterpenes with a 4,7- or 4,6-oxo bridge, were isolated from Daphne genkwa (Mianyang, Sichuan, China) (Li et al, 2015c ). (±)-Subaveniumins A ((±)- 630 ) and B ((±)- 631 ), two pairs of racemic neolignans with a rare 2-oxaspiro[4.5] deca-6,9-dien-8-one motif, were isolated from the bark of Cinnamomum subavenium (Laifeng, Hubei, China) (Lai et al, 2015 ).…”