Dynamic metabolic and transcriptomic profiling reveals the biosynthetic characteristics of hydroxycinnamic acid amides (HCAAs) in sunflower pollen.

Sunflower pollen is a natural nutritious food with a long history and multiple functions, however, the main chemical components apart from flavonoids and their biosynthesis processes have not been thoroughly investigated. In this study, seven hydroxycinnamic acid amides (HCAAs) (1-7) abundant in sunflower pollen were isolated and identified as one type of the pollen's main chemicals. For a comprehensive understanding of HCAA biosynthesis in Helianthus annuus flowers, RNA-seq, metabolomics, and key genes related to biosynthesis in the sunflower were studied. A large number of compounds at different sunflower growth stages (the 7th, 14th, 21st, and 28th days) and high expression levels of related genes in the transcriptome were detected. A molecular network was constructed to clarify the synthetic pathway of HCAAs, which revealed high transcriptional levels of spermidine hydroxycinnamoyl transferase genes (HaSHT2795 and HaSHT2436) in 14-21-days-old flowers. HaSHT2795 enzymes catalyze tri-coumaroylspermidine formation, and virus-induced gene silencing to inhibit HaSHT2795 and HaSHT2436 could significantly reduce the synthesis of hydroxycinnamic acid amides in sunflower pollen. HCAAs were inferred to be related to the formation of pollen walls and the health effects of pollen. Analyzing HCAA biosynthesis and accumulation in H. annuus pollen will be helpful to understand the functions of HCAAs in the development of pollen and its nutritional value.

Cajuputones A-C, ß-Triketone Flavanone Hybrids from the Branches and Leaves of Melaleuca cajuputi.

Three new ß-triketone flavanone hybrids, cajuputones A-C were obtained from Melaleuca cajuputi (the Australian 'tea tree'). The structures of cajuputones A-C were elucidated by 1D/2D NMR spectroscopy and HR-ESI-MS analyses; and their absolute configurations were established by electric circular dichroism (ECD) calculations using TDDFT method. Structurally, cajuputones A-C feature a rare 6/6/6/6 oxatetracyclic ring system fused between an acylphloroglucinol-derived ß-triketone and a pinocembrin or strobopinin moiety via an angle-type pyran-like motif. DFT-based conformational optimization in chloroform explained the similarity of the 1D NMR data of cajuputones B and C (C-2 epimers).

Toonasindiynes A-F, new polyacetylenes from Toona sinensis with cytotoxic and anti-inflammatory activities.

The plants of genus Toona are well known for diverse limonoid secondary metabolites, while polyacetylenes are rarely found from Toona species. In this work, six new polyacetylenes toonasindiynes A-F (1-6) and six known analogues (7-12) were isolated from the root bark of Toona sinensis. Their structures and absolute configurations were elucidated by HRESIMS, 1D and 2D NMR spectroscopic analysis, modified Mosher's method, and biosynthetic consideration. These polyacetylenes share the same 4,6-diyne moiety with different side chain length and different oxidation degree. Bioactivity screening revealed the cytotoxic activity of 3, 5, 9, and 11 against U2OS cells, and the inhibitory effects on nitric oxide (NO) production of 1, 2, 5, 8, 9, and 11 in lipopolysaccharide-induced RAW 264.7 cells.

New triterpenoids, steroids and lignan from the stem barks of Entandrophragma utile.

Eight new compounds (Entanutilins O-V; 1-8), including four limonoids, two steroids, one triterpenoid and one lignan were isolated from the stem barks of Entandrophragma utile. Their structures were determined by detailed spectroscopic analyses (HRESIMS and 1D/2D-NMR). Bioactivity screening indicated that compounds 1, 6 and 7 exhibited effective in reversing resistance in MCF-7/DOX cells at a nontoxic concentration of 30 µM with 18.18-, 7.43- and 7.94-fold enhancing effect, respectively, meanwhile, compounds 5 and 6 showed moderate NO inhibitory activities in LPS-activated RAW 264.7 macrophages.

Highly oxygenated and rearranged limonoids from the stem barks of Entandrophragma utile.

Seventeen highly oxygenated and rearranged limonoids, including nine previously undescribed phragmalin-type limonoids with 1,8,9- and 8,9,30-orthesters (entanutilins C-K, 1-9), three undescribed limonoids with rare rearranged-6/6/7/5 skeleton (entanutilins L-N, 10-12), and 5 known limonoids, were isolated from the stem barks of Entandrophragma utile from Ghana (Africa). Their structures including absolute configurations were elucidated based on comprehensive spectroscopic analyses, such as HRESIMS, 1D/2D-NMR, CD exciton chirality method, time-dependent density functional theory (TDDFT)/ECD calculations, and single-crystal X-ray diffraction. Bioactivity screenings suggested that some of these compounds effectively reversed resistance in MCF-7/DOX cells at a nontoxic concentration of 30 µM with 6- to 19-fold enhancing effects.

Anti-inflammatory activity of Khayandirobilide A from Khaya senegalensis via NF-κB, AP-1 and p38 MAPK/Nrf2/HO-1 signaling pathways in lipopolysaccharide-stimulated RAW 264.7 and BV-2 cells.

BACKGROUND: Immunocytes-involved inflammation is considered to modulate the damage in various diseases. Herein, novel therapeutics suppressing over-activation of immunocytes could prove an effective strategy to prevent inflammation-related diseases. PURPOSE: The objective of this study is to evaluate the anti-inflammatory activity of Khayandirobilide A (KLA), a new andirobin-type limonoid with modified furan ring isolated from the Khaya senegalensis (Desr.) A. Juss., and to explore its potential underlying mechanisms in LPS-stimulated inflammatory models. METHODS: The structure of KLA was elucidated on the basis of 1D- and 2D-NMR spectroscopic data as well as HR-ESI-MS. As for its anti-inflammatory effect, the production of pro-inflammatory mediators and cytokines in LPS-stimulated RAW 264.7 and BV-2 cells were measured by Griess reagent, ELISA and qRT-PCR. The relevant proteins including nuclear factor κB (NF-κB), p-AKT, p-p38 and Nrf2/HO-1 were investigated by western blot. Nuclear localisations of NF-κB, activator protein-1 (AP-1) and Nrf2 were also examined by western blot and immunofluorescence. RESULTS: KLA could inhibit the production of LPS-induced NO with IC50 values of 5.04 ±â€¯0.14 µM and 4.97 ±â€¯0.5 µM in RAW 264.7 and BV-2 cells, respectively. KLA also attenuated interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein and mRNA levels. Further mechanistic studies demonstrated the activation of NF-κB and AP-1 were reduced by KLA. Moreover, KLA elevated expression of heme oxygenase-1(HO-1) via inducing Keap1 autophagic degradation and promoting Nrf2 nuclear translocation. Despite KLA induced the phosphorylation of mitogen-activated protein kinases (MAPKs) family, inhibiting the phosphorylation of p38 by its specific inhibitor SB203580 attenuated the degradation of KLA-induced Keap1, and then reduced KLA-induced Nrf2 nuclear translocation and HO-1 expression. Furthermore, SB203580, Brusatol (a Nrf2 specific inhibitor) and ZnPP (a HO-1 specific inhibitor) could partly reverse the suppressive effects of KLA on LPS-induced NO production and mRNA levels of pro-inflammatory genes. CONCLUSION: These data displayed that KLA possessed anti-inflammatory activity, which was attributed to inhibit the release of LPS-stimulated inflammatory mediators via suppressing the activation of NF-κB, AP-1, and upregulating the induction of p38 MAPK/Nrf2-mediated HO-1.