Search Results (5)

Callicarpa giraldii Hesse ex Rehd. is an endemic plant in China and has long been used as a traditional medicine in several provinces. Although the plant has been reported to contain flavonoids, triterpenes, and alkaloids, this study represents the first report of the isolation of phyllocladane-type diterpenoids, a relatively rare class of compounds. In this study, 18 new phyllocladane-type diterpenoids (7–24) were isolated and structurally elucidated, including eight uncommon 3,4-seco phyllocladane-type diterpenoids (15–22) and two unusual phyllocladane-type diterpene dimers (23–24), along with six known analogues (1–6). Their structures were elucidated by a comprehensive analysis of 1D and 2D NMR, IR, and HRESIMS data. The absolute configurations were determined by single crystal X-ray diffraction experiments, DFT NMR calculations, and TDDFT ECD calculations. Based on the obtained and reported spectroscopic data, we refined a rule to distinguish phyllocladane-type diterpenoids from their diastereomeric ent-kaurane-type compounds. Additionally, the isolated compounds were evaluated for their in vitro anti-neuroinflammatory activity against lipopolysaccharide (LPS)-induced inflammation in BV-2 microglial cells. Compounds 5, 10, 13, 18, 19, and 20 showed moderate inhibitory activity at the concentration of 20 μM, with compounds 5 and 13 markedly reducing the mRNA levels of the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α at this concentration. Full article

Psoriasis, an immune-mediated inflammatory skin disorder, seriously affects the quality of life of nearly four percent of the world population. Euphorbia helioscopia L. is the monarch constituent of Chinese ZeQi powder preparation for psoriasis, so it is necessary to illustrate its active ingredients. Thus, twenty-three diterpenoids, including seven new ones, were isolated from the whole herb of E. helioscopia L. Compounds 1 and 2, each featuring a 2,3-dicarboxylic functionality, are the first examples in the ent-2,3-sceo-atisane or the ent-2,3-sceo-abietane family. Extensive spectroscopic analysis (1D, 2D NMR, and HRMS data) and computational methods were used to confirm their structures and absolute configurations. According to the previous study and NMR data from the jatropha diterpenes obtained in this study, some efficient ¹H NMR spectroscopic rules for assigning the relative configurations of 3α-benzyloxy-jatroph-11E-ene and 7,8-seco-3α-benzyloxy-jatropha-11E-ene were summarized. Moreover, the hyperproliferation of T cells and keratinocytes is considered a key pathophysiology of psoriasis. Anti-proliferative activities against induced T/B lymphocytes and HaCaT cells were tested, and IC₅₀ values of some compounds ranged from 6.7 to 31.5 μM. Compounds 7 and 11 reduced the secretions of IFN-γ and IL-2 significantly. Further immunofluorescence experiments and a docking study with NF-κB P65 showed that compound 13 interfered with the proliferation of HaCaT cells by inhibiting the NF-κB P65 phosphorylation at the protein level. Full article

Two undescribed ent-kaurene diterpenes, named guidongnins I (1) and J (2), were isolated from the medicinal plant Isodon rubescens. Compound 1 was determined to contain an unprecedented 23 carbons in the skeleton by bearing an extra isopropyl group at C-17 out of the diterpenoid parent structure, and compound 2 was the first example of 6,7-seco-7,20-olide-ent-kaurenes with two fused-tetrahydrofuran rings formed between C-6 and C-19/C-20 through oxygen bridges. Their structures, including their absolute configurations, were determined using the analyses of the spectroscopic and X-ray diffraction data. Guidongnins I (1) and J (2) were assessed for their anti-cancer activities against the growth of various cancer cell lines, and 2 displayed cytotoxic potency against HepG2 at IC₅₀ 27.14 ± 3.43 μM. Full article

Castanea crenata (Fagaceae) is a species of chestnut tree that is endemic to the Republic of Korea and Japan. While its kernels are consumed, chestnut by-products such as shells and burs, which account for 10–15% of the total weight, are discarded as waste. Phytochemical and biological studies have been carried out to eliminate this waste and develop high-value products from its by-products. In this study, five new compounds (1–2, 6–8) along with seven known compounds were isolated from the shell of C. crenata. This is the first study to report diterpenes from the shell of C. crenata. Comprehensive spectroscopic data including 1D, 2D NMR, and CD spectroscopy were used to determine the compound structures. All isolated compounds were examined for their ability to stimulate dermal papilla cell proliferation using a CCK-8 assay. In particular, 6β,7β,16α,17-Tetrahydroxy-ent-kauranoic acid, isopentyl-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside, and ellagic acid exhibited the most potent proliferation activity of all. Full article

A new atisane-type diterpene, ent-16α-hydroxy-atisane-3,4-lactone (4) and three known diterpenes, ent-16α-hydroxy-atisane-3-one (1), ent-atisane-3β,16α-diol (2), ent-3,4-seco-16α-hydroxyatis- 4(19)-en -3-oic acid (3) were isolated from the bark of the mangrove plant Excoecaria agallocha. Their structures and relative stereochemistry were elucidated by means of extensive NMR and MS analysis. Compound 3 exhibited significant anti-microfouling activity against the adherence of Pseudomonas pseudoalcaligenes, with an EC₅₀ value of 0.54 ± 0.01 ppm. Full article