Chemical constituents from the twigs and leaves of Picrasma quassioides

Two new compounds, including a norsesquiterpenoid, annuionone H (1), and a quassinoid, picraqualide G (2), along with eleven known compounds (3-13), were isolated from the twigs and leaves of Picrasma quassioides. Comprehensive spectroscopic analyses and NMR calculation with DP4+ analysis were used to identify their structures. Moreover, of all these compounds, compound 4 showed a week inhibition rate in the anti-inflammatory screening results against mouse macrophage J774A.1 cell.

Structurally Diverse Metabolites from the Marine-Derived Streptomyces sp. DS-27 Based on Two Different Culture Conditions

Nine new compounds, including streptothiomycin A-E (1-5), two cyclopentenones (6, 7), one α-pyrone (8), wailupemycin Q (20), along with sixteen known compounds were identified from a rhizosphere strain Streptomyces sp. DS-27 derived from the marine cordgrass Spartina alterniflora under two different culture conditions. All of the structures were elucidated by extensive analysis of 1D/2D NMR and HR-ESI-MS data. The absolute configurations were determined by NOESY analysis, ECD, specific rotation and GIAO NMR calculations, and DP4+ probability analysis. Bioactivity investigation showed that compounds 5 and 7 exhibited significant inhibitory effects on LPS-induced NO production in a dose-dependent manner, which indicates their anti-inflammatory potential.

A new butylphthalide from Ligusticum striatum DC

One new butylphthalide ligusticumolide H (1), together with the known butylphthalides senkyunolide I (2), senkyunolide H (3), (3 R,3'S)-3'-hydroxy-3-butylphthalide (4), (3 R)-4-hydroxy-3-butylphthalide (5) and senkyunolide C (6) was isolated from the rhizome of Ligusticum striatum DC. Their structures were determined by extensive spectroscopic analyses including HR-ESI-MS, 1D and 2D NMR, and the absolute configuration of 1 was established by NMR and ECD calculations. Their effect on NO production in IL-1β-stimulated chondrocytes was also evaluated.

Monoterpene Alkaloids from Incarvillea delavayi Bureau et Franchet and Their Inhibition against LPS Induced NO Production in BV2 Cells

Three new monoterpene alkaloids, delavatines C-E (1-3), along with five known ones (4-8), were separated from the whole plants of Incarvillea delavayi. All compounds were deduced by interpretation of comprehensive NMR spectral data and X-Ray single crystal diffraction, in combination with a quantum chemical calculation of NMR chemical shift coupled with an advanced statistical procedure DP4+. Compounds 1-8 were assessed NO suppressive effect in LPS-stimulated BV2 microglia cells. Compounds 2, 3, 6, and 8 exhibited significant inhibition against NO production in LPS-induced BV2 cells with IC₅₀ values of 25.62, 17.29, 19.94 and 23.88 μM, stronger than or comparable to the positive control (AG) with IC₅₀ value of 26.13 μM.

Four new polycyclic polyprenylated acylphloroglucinols from Hypericum wilsonii and their glucose uptake bioactivities

Wilsonglucinols H-K (1-4), four new polycyclic polyprenylated acylphloroglucinols (PPAPs), and eight known compounds (5-12) were isolated and identified from the aerial parts of Hypericum wilsonii. Their planner structures were confirmed via extensive NMR and HRESIMS data analysis. The absolute configurations of the new compounds were mainly determined by NMR calculation and electronic circular dichroism (ECD) calculation. Compounds 1, 6, 8, and 10 showed glucose uptake activities at 30 μg/mL, in which compound 6 showed the strongest effect and increased the glucose uptake by 2.73 folds.

Synthesis and DFT-NMR-guided structure revision of cremenolide

The structure of an anti-plant pathogenic and plant growth-promoting nonenolide, namely cremenolide, was revised by an efficient combination of DFT-based theoretical NMR calculations and synthesis of a target diastereomer. Initially, the planar structure of cremenolide was reconsidered by an individual analysis of the reported NMR spectra. Subsequently, the relative configuration was predicted using NMR calculations of all possible diastereomers based on the ωB97X-D functional. Finally, the relative configuration of cremenolide was unambiguously confirmed by preparation of the proposed structure.

Aplydactylonins A-C, three new sesquiterpenes from the Vietnamese sea hare Aplysia dactylomela and their cytotoxicity

Aplydactylonins A-C (1-3), three new sesquiterpenes, were isolated from the Vietnamese sea hare Aplysia dactylomela. Their structures and absolute configurations were elucidated based on spectroscopic analysis, X-ray crystallography, and density functional theory (DFT) calculations of NMR and ECD data. Compound 2 exhibited cytotoxicity against HepG2, DU145 and A549 cells with respective IC₅₀ values of 4.08 ± 0.63, 38.64 ± 1.04 and 12.33 ± 0.95 µM. In addition, HepG2 cells treated with 5 μM compound 2 for 48 h showed a significant increase in early apoptotic cells (P < 0.05) and increased caspase 3 activity (P < 0.01). Moreover, compound 2 induced sub-G1 phase arrest in HepG2 cells.

Agallochin P, a new diterpene from Vietnamese mangrove Excoecaria agallocha L

A new diterpene (1) along with eight known compounds (2-9) were isolated from Excoecaria agallocha leaves. The structure and relative configuration of new compound were established on the basis of spectroscopic data analysis and confirmed by NMR chemical shifts calculation with DP4+ probability. Cytotoxicity of the isolated compounds were also evaluated.

Terpenylated coumarins from the root bark of Ailanthus altissima (Mill.) Swingle

Seven undescribed terpenylated coumarins, named altissimacoumarin I-O, together with seven known compounds, altissimacoumarin C, altissimacoumarin E, altissimacoumarin G, altissimacoumarin H, puberulin, 7-(3-Methyl-2-butenyloxy)-6-methoxycoumarin and artelin were isolated from the root bark of Ailanthus altissima (Mill.) Swingle. Their structures were elucidated by comprehensive spectra data analysis, NMR calculation, DP4+ analysis and ACD/Structure Elucidator software simulation. The absolute configurations of altissimacoumarins K, L, M and N were determined by modified Mosher's method. All isolates were tested for their cytotoxic effect against two hepatoma carcinoma cell lines (HepG2, Hep3B). Altissimacoumarin C exhibited moderate cytotoxic effect against Hep3B cells, with IC₅₀ of 45.21 μM.

Miscellaneous lanostane triterpenoids with cytotoxicities from fruiting bodies of the basidiomycete Stereum sp

Ten new highly oxygenated lanostane triterpenoids, stereinones A-J (1-10), were isolated from the fruiting bodies of the basidiomycete Stereum sp. Compounds 3 and 4 are structurally characterized as intact lanostane-type triterpenoids containing unusual 1,2-diketone functionality at C-11 and C-12, while compound 10 is a 24-methylene-lanostane. The structures of these new compounds were established based on detailed 1D and 2D NMR spectroscopic analyses, along with quantum chemical NMR calculations. All isolates were evaluated for their in vitro cytotoxicities against five human tumor cell lines (including HL-60, A-549, SMMC-7721, MCF-7, and SW480 cell lines). Compound 4 showed moderate cytotoxic activities against tumor cell lines SMMC-7721 and SW480 with IC₅₀ values of 9.1 and 9.8μM, respectively.