Cytotoxic Diterpenoids from Caryopteris aureoglandulosa.

Seven new (1-7) and 11 known diterpenoids were isolated and identified from Caryopteris aureoglandulosa. These diterpenoids were structurally determined by HRESIMS and NMR spectroscopic analyses, single-crystal X-ray diffraction, and ECD data. Structurally, aureoglandulosin A (1) is a highly oxygenated abietane diterpenoid with an unprecedented 7/6/6/5-ring system. Aureoglandulosins B (2) and C (3) represent naturally occurring new diterpenoids with an unusual 6/6/6/5-ring system. Additionally, the configurations of two known abietane diterpenoids 11 and 12 were determined by X-ray crystallographic data analysis for the first time. A plausible biosynthetic pathway for compounds 1-3 is proposed. The cytotoxicity of all isolates was evaluated, and compounds 1 and 11 exhibited significant cytotoxic activity against some cell lines with IC50 values in the range 1.6-8.2 µM.

Abietane diterpenoids from Caryopteris incana (Thunb.) Miq.

Twelve new diterpenes, caryopincaolide A-L (1-4, 11-12, 16-19, 27-28), together with twenty-eight known diterpenes, have been isolated from the whole plant of Caryopteris incana (Thunb.) Miq. Their structures were elucidated on the basis of 1D and 2D NMR, IR, X-ray crystal diffraction and mass spectroscopic data, as well as ECD calculations. All compounds were tested for in vitro dipeptidyl peptidase IV (DPP-IV) inhibitory activity, with compounds 3, 4, 28, 29, and 40 exhibiting DPP-IV inhibitory effects with IC50 values ranging from 54.2 to 228.9 µM. Compounds 1, 3 and 4 also showed potent activity toward the inhibition of the growth of human cancer cells and 1 can induce apoptosis in Hey and A-549 cells.

New Iridoid Glucosides from Caryopteris incana (Thunb.) Miq. and Their α-Glucosidase Inhibitory Activities.

In our continued investigations of the plant Caryopteris incana, five new iridoid glucosides 1-5, including two cis-trans-isomers, 3 and 4, along with six known compounds 6-11, were isolated from the n-butyl alcohol (n-BuOH) soluble fraction of whole dried material of Caryopteris incana. Their structures were established by a combination of spectroscopic techniques, including 1D and 2D NMR and high resolution electrospray ionization mass spectroscopy (HR-ESI-MS). Furthermore, all isolates were evaluated for their yeast α-glucosidase inhibitory effects. Among these compounds, 4-8 and 10 exhibited potent inhibition of α-glucosidase.

Caryopincaolide M, a rearranged abietane diterpenoid with new skeleton and a new iridoid from Caryopteris incana.

Caryopincaolide M (1), a new rearranged abietane diterpenoid with an unusual pent-4-enoic acid group on a 6/6/5 tricyclic ring system, and 7-epi-8-dehydroxypatriscabrol (3), a new iridoid, together with 17 known compounds, have been isolated from the whole plant of Caryopteris incana (Thunb.) Miq. Their structures were elucidated on the basis of 1-D and 2-D NMR, IR, and mass spectroscopic data. Compounds 1-5 were evaluated for their inhibitory activities against enzyme α-glucosidase, and the results showed that only 1 has moderate inhibitory activity against enzyme α-glucosidase with IC50 at 528.3 ± 12.37 mg/L.