Caulophyine A, a Rare Azapyrene Alkaloid from the Roots of Caulophyllum robustum.

A novel alkaloid caulophyine A (1) was isolated from the roots of Caulophyllum robustum Maxim., along with six known alkaloids 2-7. The structure of 1 was elucidated by extensive NMR and high resolution-time-of-flight (HR-TOF)-MS analyses, it is a rare nitrogen containing polycyclic aromatic hydrocarbon. The in vitro bioassays revealed that 2 presented remarkable cytotoxicity against A549 with an IC50 value of 3.83 µM in comparison with the positive control etoposide (IC50 = 11.63 µM). Compounds 1 and 2 also displayed weak Acetylcholinesterase (AChE) inhibitory activity with IC50 values of 123.03 and 80.74 µM respectively.

Asperfloketals A and B, the First Two Ergostanes with Rearranged A and D Rings: From the Sponge-Associated Aspergillus flocculosus 16D-1.

Asperfloketals A (1) and B (2), two 1(10 → 6)-abeo-14,15-secosteroids featuring a novel trioxahexaheterocyclic ring system, were isolated from the sponge-associated fungus Aspergillus flocculosus 16D-1. Their structures were elucidated by extensive spectroscopic analysis and NMR chemical shifts calculations, supported by DP4+ probability analysis, and their absolute configurations were determined by ECD calculations and the modified Mosher's method. Asperfloketals A and B showed strong anti-inflammatory activity in the CuSO4-induced transgenic fluorescent zebrafish but displayed no cytotoxicity against HeLa, HepG2, and SW480 cell lines.

Asperflotone, an 8(14→15)- abeo-Ergostane from the Sponge-Derived Fungus Aspergillus flocculosus 16D-1.

A novel 8(14→15)- abeo-ergostane-type steroid, asperflotone (1), and an ergostane steroid, asperfloroid (2), were isolated from the solid culture of Aspergillus flocculosus 16D-1. Their structures and absolute configurations were determined by high-resolution electrospray ionization mass spectrometry, 1D/2D NMR, X-ray crystallography, and quantum chemical calculations. Compound 1 is an unprecedented ergosteroid featuring a rearranged bicyclo[4.2.1]non-2-ene ring system that could result from α-ketol rearrangement during biosynthesis. Compounds 1 and 2 showed inhibitory activity toward IL-6 production in the induced THP-1 cells.

Preussins with Inhibition of IL-6 Expression from Aspergillus flocculosus 16D-1, a Fungus Isolated from the Marine Sponge Phakellia fusca.

New pyrrolidine alkaloids, preussins C-I (1-7) and (11 R)/(11 S)-preussins J and K (8 and 9), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. The structures and configurations of these preussins were elucidated by detailed spectroscopic analysis, modified Mosher's method, and comparisons with literature data. These compounds showed strong to moderate inhibitory activity toward IL-6 production in lipopolysaccharide-induced THP-1 cells with IC50 values ranging from 0.11 to 22 µM, but were inactive against normal tumor cell lines and fungi.

Constituents with potent α-glucosidase inhibitory activity from Pueraria lobata (Willd.) ohwi.

One new flavone hydrate named lobatflavate (1), one new chromone named lobatchrosin (2), and one new isoflavone named 3S,4R-tuberosin (3), along with four known isoflavone analogues (4-7), were isolated from the traditional Chinese medicinal plant of Pueraria lobata (Willd.) ohwi. Their structures were elucidated by extensive spectroscopic methods of IR, UV, HR-ESI-MS, 1D and 2D NMR. The absolute configuration of 3 was determined by CD spectrum associated with TD-DFT calculation analysis. All compounds except for 2 were assayed the inhibitory activity against α-glucosidase. Every tested compound was proved to be more active than positive control of acarbose. Of which 1 and 4 showed significant activity with IC50 value of 1.79µM and 23.01µM (IC50 of acarbose was 1998.79µM). Enzyme kinetic experiments revealed that 1 was irreversible whereas 4 was reversible and non-competitive α-glucosidase inhibitors. Moreover, structure-activity relationship was discussed and the docking studies of 1, 3 and 4 were also carried out.

Ochrasperfloroid, an ochratoxin-ergosteroid heterodimer with inhibition of IL-6 and NO production from Aspergillus flocculosus 16D-1.

A novel ochratoxin-ergosteroid heterodimer, ochrasperfloroid (1), together with a known mycotoxin, ochratoxin A (2), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. The structure of 1 was determined on the basis of 1D/2D NMR, HRESIMS/MS, and LC-UV/MS analysis of its alkaline hydrolyzates, quantum-chemical 13C NMR calculation, and comparison with literature data. Of note, the ergosteroid embedded in 1 is also a new structure. Ochrasperfloroid (1) showed potent inhibitory activity towards IL-6 production in lipopolysaccharide (LPS)-induced THP-1 cell line, with an IC50 value of 2.02 µM, and NO production in LPS-activated RAW264.7 macrophages, with an IC50 value of 1.11 µM.

Aspersecosteroids A and B, Two 11(9 → 10)- abeo-5,10-Secosteroids with a Dioxatetraheterocyclic Ring System from Aspergillus flocculosus 16D-1.

Two 11(9 → 10)- abeo-5,10-secosteroids possessing an unprecedented dioxatetraheterocyclic ring system, aspersecosteroids A (1) and B (2), and a new ergosteroid, asperflosterol (3), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. Their structures were determined by spectroscopic analysis, X-ray diffraction, and computational methods. Compounds 1-3 demonstrated inhibitory effects on key pro-inflammatory cytokine production in THP-1 cells. A biogenetic pathway with oxidative cleavage, Wagner-Meerwein rearrangement, and sequential acetalization as key steps is proposed for 1 and 2.