Pinuseldarone, a Clerodane-Type Diterpene from Pinus eldarica Needles and Phytochemicals as Novel Agents for Regulating Brown Adipogenesis and Thermogenesis.

Phytochemical investigation of the MeOH extract of Pinus eldarica needles led to the isolation and identification of a new clerodane-type diterpene, pinuseldarone (1), along with a known flavonoid, 5,4'-dihydroxy-3,7,8-trimethoxy-6-C-methylflavone (2), through HPLC purification. The structure of the new compound 1 was elucidated using spectroscopic methods, including 1D and 2D NMR, as well as HRESIMS. Its absolute configuration was established through NOESY analysis and computational methods, including electronic circular dichroism (ECD) calculations and gauge-including atomic orbital NMR chemical shift calculations, followed by DP4+ probability analysis. The metabolic implications of the isolated compounds were assessed using a cultured brown adipocyte model derived from murine brown adipose tissue. It was observed that treatment with dihydroxy-3,7,8-trimethoxy-6-C-methylflavone (2) downregulates the adipogenic marker C/EBPδ and fatty acid transporter CD36, resulting in a significant reduction in lipid accumulation during brown adipocyte differentiation. However, pinuseldarone (1) treatment did not affect brown adipocyte differentiation. Interestingly, pretreatment with pinuseldarone (1) potentiated the pharmacological stimulation of brown adipocytes, seemingly achieved by sensitizing their response to ß3-adrenoreceptor signaling. Therefore, our findings indicate that phytochemicals derived from P. eldarica needles could potentially serve as valuable compounds for adjusting the metabolic activity of brown adipose tissue, a vital component in maintaining whole-body metabolic homeostasis.

Anti-Adipogenic Effects of Salicortin from the Twigs of Weeping Willow (Salix pseudolasiogyne) in 3T3-L1 Cells.

Salix pseudolasiogyne (Salicaceae), the "weeping willow," has been used in traditional Korean medicine to treat pain and fever due to its high concentrations of salicylic acid and salicin. The present study investigated bioactive compounds from S. pseudolasiogyne twigs to discover bioactive natural products. Phytochemical investigation of the ethanol (EtOH) extract of S. pseudolasiogyne twigs followed by liquid chromatography-mass spectrometry (LC/MS)-based analysis led to the isolation of two salicin derivatives, salicortinol and salicortin, the structures of which were determined by interpretation of their NMR spectra and data from the LC/MS analysis. To the best of our knowledge, this is the first report of salicortinol isolated from S. pseudolasiogyne. The isolated compounds were evaluated for their anti-adipogenic effects in 3T3-L1 cells. Both salicortinol and salicortin were found to significantly inhibit adipocyte differentiation in 3T3-L1 cells. In particular, salicortin exhibited a strong inhibitory effect on lipid accumulation. Furthermore, salicortin inhibited the expression of lipogenic and adipogenic transcription factors, including FASN, FABP4, C/EBPα, C/EBPß, and PPARγ, without inducing cytotoxicity. These results suggest that salicortin could be a potential therapeutic compound for the prevention or treatment of metabolic disorders such as obesity.

Labdane-type Diterpenes from Pinus eldarica Needles and Their Anti-Helicobacter pylori Activity.

Pinus eldarica is a medicinal tree used in traditional herbal medicine for the treatment of bronchial asthma and various skin diseases. As part of our ongoing search for bioactive phytochemicals with novel structures in natural products, we performed a phytochemical analysis of the methanol (MeOH) extract from P. eldarica needles collected in Iran. Phytochemical investigation of the MeOH extract, aided by liquid chromatography-mass spectrometry-based analysis, resulted in the isolation and identification of three labdane-type diterpenes (1-3), including a new and relatively unique norlabdane-type diterpene with a peroxide moiety, eldaricoxide A (1). The chemical structures of the isolated labdane-type diterpenes were elucidated by analyzing the spectroscopic data from 1D and 2D NMR and high-resolution electrospray ionization-mass spectrometry. The absolute configuration of eldaricoxide A (1) was established by employing a computational method, including electronic circular dichroism calculation and specific optical rotation. An anti-Helicobacter pylori test was conducted, where compound 3 exhibited the most potent antibacterial activity against H. pylori strain 51, inducing 72.7% inhibition (MIC50 value of 92 µM), whereas eldaricoxide A (1) exhibited moderate antibacterial activity against H. pylori strain 51, inducing 54.5% inhibition (MIC50 value of 95 µM). These findings demonstrated that the identified bioactive labdane-type diterpenes 1 and 3 can be applied in the development of novel antibiotics against H. pylori for the treatment of gastric and duodenal ulcers.