Characteristic cembrane-type diterpenoids with nitric oxide inhibitory activity from the gum resin of Boswellia carterii Birdw.

Five new characteristic cembrane-type diterpenoids (olibacartiols A-E, 1-5) were acquired from the gum resin of Boswellia carterii. The structures of these diterpenoids were characterized by detailed spectroscopic analysis, and compounds 1-3 were unambiguously confirmed by single-crystal X-ray diffraction experiments. The anti-inflammatory activities of the isolated compounds were evaluated using LPS-induced BV2 cell model and compounds 2-5 showed moderate NO inhibitory effects with IC50 values of 8.84 ±â€¯1.02, 9.82 ±â€¯1.95, 9.75 ±â€¯2.24, and 7.39 ±â€¯1.24 µM, respectively.

Lindenane sesquiterpenoid monomers and oligomers: Chemistry and pharmacological activities.

Lindenane sesquiterpenoid monomers and oligomers, characterized by a sterically congested cyclopentane and an unusual trans-5/6 ring junction, are mainly found in Chloranthaceae species and the genus Lindera Thunb (Lauraceae). Numerous studies have shown that lindenane sesquiterpenoid monomers and oligomers exhibit a broad range of biological activities, such as cytotoxicity, anti-inflammation, neuroprotection, antifungal, and anti-malarial activities. This review covers publications from the first identification of lindeneol in 1925-2023 and classifies the lindenane sesquiterpenoid derivatives into sesquiterpenoid monomers, sesquiterpenoid-monoterpene conjugates, sesquiterpenoid homodimers, sesquiterpenoid heterodimers, and trimeric sesquiterpenoids. In addition, their biological activities are summarized. This review will establish a scientific basis and provide guidance for utilizing this unique class of natural products as potential lead compounds to develop their application in treating diseases corresponding to inflammation, cancer, and plasmodium.

A calcium-dependent lipid binding protein, OsANN10, is a negative regulator of osmotic stress tolerance in rice.

Annexin, a multi-gene family in plants, is essential for plant growth and stress responses. Recent studies demonstrated a positive effect of annexin in abiotic stress responses. Interestingly, we found OsANN10, a putative annexin gene in rice, negatively regulated plant responses to osmotic stress. Knocking down OsANN10 significantly decreased the content of H2O2 by increasing Peroxidase (POD) and Catalase (CAT) activities, further reducing oxidative damage in rice leaves, suggesting a negative regulation of OsANN10 in protecting cell membrane against oxidative damage via scavenging ROS under osmotic stress.

A calcium-binding protein, rice annexin OsANN1, enhances heat stress tolerance by modulating the production of H2O2.

OsANN1 is a member of the annexin protein family in rice. The function of this protein and the mechanisms of its involvement in stress responses and stress tolerance are largely unknown. Here it is reported that OsANN1 confers abiotic stress tolerance by modulating antioxidant accumulation under abiotic stress. OsANN1-knockdown [RNA interference (RNAi)] plants were more sensitive to heat and drought stresses, whereas OsANN1-overexpression (OE) lines showed improved growth with higher expression of OsANN1 under abiotic stress. Overexpression of OsANN1 promoted SOD (superoxide dismutase) and CAT (catalase) activities, which regulate H2O2 content and redox homeostasis, suggesting the existence of a feedback mechanism between OsANN1 and H2O2 production under abiotic stress. Higher expression of OsANN1 can provide overall cellular protection against abiotic stress-induced damage, and a significant accumulation of OsANN1-green fluorescent protein (GFP) signals was found in the cytosol after heat shock treatment. OsANN1 also has calcium-binding and ATPase activities in vitro, indicating that OsANN1 has multiple functions in rice growth. Furthermore, yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays demonstrated that OsANN1 interacts with OsCDPK24. This cross-talk may provide additional layers of regulation in the abiotic stress response.