Diterpenoids caryopterisoids D - Q and iridoid glucoside derivatives caryopterisides F - H from Caryopteris glutinosa

A new abietane diterpene tuurgan a from caryopteris mongholica

Five abietane diterpenes compounds were separated from petroleum ether extraction sites of ethanol extract of Caryopteris Mongholica, and Compound 1 was identified as a new abietane diterpenes compound by NMR and mass spectrometry, named as Tuurgan A of Caryopteris Mongholica; and Compounds 2-5 separated from Caryopteris Mongholica for the first time were identified as Ferruginol (2), Taxodione (3), Caryopterisoid Q (4), and Huperphlegmarin B (5). The anti-lung cancer activity of the Compounds 1-5 were determined, which results showed that they all had high A549 cytotoxicity.

Antifibrotic pyridine-containing monoterpene alkaloids from Caryopteris glutinosa

Three undescribed dimeric pyridine-containing alkaloids, caryopterisines C - E, and four unreported cyclopenta[c]pyridine-derived alkaloids, caryopterisines F - I, were identified from Caryopteris glutinosa Rehder (Lamiaceae), together with two known monoterpene alkaloids. Caryopterisine C, featuring with an unprecedented 6/5/6/6/5 pentacyclic rings scaffold, may biosynthetically stem from a Diels-Alder reaction of two cyclopenta[c]pyridine-containing monomers and a following aromatization rearrangement reaction. Caryopterisines D and E, possessing an unprecedented 6/6/6/6/5 fused rings framework, may originate from a same Diels-Alder reaction of two monomers and subsequent aromatization arrangement, Baeyer-Villiger oxidation, and a set of tailoring reactions. Caryopterisine C showed strong inhibition on collagen accumulation in NIH3T3 cells (IC₅₀ = 14.26 ± 1.46 μM). Caryopterisines G and I reduce collagen accumulation with IC₅₀ values 88.91 ± 0.95 μM and 33.09 ± 1.38 μM, respectively. The Western blotting of the transforming growth factor-β-activated signaling pathways revealed that caryopterisine C inhibits collagen expression and accumulation via suppression of the phosphorylation of ERK1/2, P38, and SMAD2/3. The present works indicate caryopterisine C is a potential lead compound for the development of antifibrotic drugs.

(±)-Caryopterisines A and B, dimeric monoterpene alkaloids with unprecedented 6/5/5/5/6 pentacyclic rings scaffold from Caryopteris glutinosa

(±)-Caryopterisines A (1) and B (2) featuring an unprecedented 6/5/5/5/6 pentacyclic rings system were isolated from Caryopteris glutinosa. The structures were determined by spectroscopic and X-ray crystallographic data analyses as well as theoretical calculations. Chiral HPLC resolution of both racemic 1 and 2 afforded their corresponding enantiotropic enantiomers. A plausible biogenesis for 1 and 2 may be originated from Diels-Alder reaction between pyridine-containing oxerine derivatives. The enantiotropic conversion mechanism of the enantiomers was demonstrated by H-D exchange and ¹⁸O incorporation studies. Compounds 1 and 2 showed moderate inhibition of estrogen E2 biosynthesis in human ovarian granulosa-like KGN cells. These two alkaloids reduced kynurenine biosynthesis at moderate level via inhibition of indoleamine 2,3-dioxygenase. Alkaloid 2 exhibited moderate inhibition of the release of interleukin-1β.