Maoeriocalysins A–D, four novelent-kaurane diterpenoids fromIsodon eriocalyxand their structure determination utilizing quantum chemical calculation in conjunction with quantitative interproton distance analysis

Abstract

Maoeriocalysin A, an unprecedented 4,5-seco-3,5-cyclo-7,20-epoxy-ent-kauranoid, together with three rare 9,10-seco-ent-kauranoids, maoeriocalysins B–D, were isolated.

A critical review on the use of DP4+ in the structural elucidation of natural products: the good, the bad and the ugly. A practical guide

“…5). 40,128,169,215,216 For instance, Lee and co-workers were able to determine most of the structure of the diterpenoid 24, 215 but the experimental NMR data was inconclusive to establish the oxygenated motif (C 12 -C 13 -C 15 ). Hence, Fig.…”

Natural Sesquiterpenoids, Diterpenoids, Sesterterpenoids, and Triterpenoids with Intriguing Structures from 2017 to 2022

“…Maoeriocalysin A ( 64 ), [ 96 ] a novel rearranged ent ‐kaurane diterpenoid with an unprecedented 4,5‐ seco ‐3,5‐cyclo‐7,20‐ epoxy‐ ent ‐kaurane skeleton, have been isolated from Isodon eriocalyx . Another highly rearranged and dual‐bridged spiro ent ‐kaurane diterpenoid crokonoid A ( 65 ) has been isolated from Croton kongensis .…”

Anti-Inflammatoryent-Kaurane Diterpenoids fromIsodon serra

“…and comprising approximately 150 species, is mainly distributed in tropical and subtropical Asia . Over the last half a century, a series of phytochemical investigations of this genus have been conducted for its abundant diterpenoid constituents and their various biological activities. − As a result, over 1200 new diterpenoids have been isolated from Isodon plants, − including some ent -kauranoids with excellent antitumor and anti-inflammatory activities, such as oridonin, eriocalyxin B, and isoforretin A …”