Novel Sesquiterpenoids with Renoprotective Activities from the Fruits of Alpinae oxyphylla as Potent TGF-β1/Smads Phosphorylation Inhibitors

The fruit of Alpinia oxyphylla Miq is an important food spice in southern China and has been used in the treatment of kidney disorders for centuries. In order to discover the natural products with potent renoprotective activities in A. oxyphylla and provide some references for its usage, systematic phytochemical studies were carried out and 24 new diverse sesquiterpenoids, including seven guaiane sesquiterpenoids (1-7), 10 eudesmane sesquiterpenoids (9-13, 18, 19, and 21-23), six cadinane sesquiterpenoids (31-35 and 38), and an eremophilane sesquiterpenoid (40), along with 24 known analogues were isolated and elucidated by analysis of spectroscopic data and quantum-chemical calculations. Biological evaluation showed that 6 sesquiterpenoids could significantly inhibit the expression of extracellular matrix components, α-SMA in TGF-β1 induced kidney proximal tubular cells (NRK-52e) at low concentrations, and 9 sesquiterpenoids could also downregulate fibronectin and collagen I in a concentration-dependent manner, showing their potential in renal fibrosis. Further action mechanism study displayed that TGF-β1/Smads pathway might be involved in the antifibrotic effects of active sesquiterpenoids 15 and 43. These studies suggest that A. oxyphylla may have a potential to serve as a functional food in preventing renal fibrosis-associated diseases.

Rare noreudesmane sesquiterpenoids from the fruits of Dysoxylum densiflorum

Seven rare noreudesmane sesquiterpenoids (dysoxydenones M-S, 1-7), including three 11,12,13-trinoreudesmanes, three 13-noreudesmanes and one spirovetivane-type sesquiterpenoid, along with two known analogues were isolated from the fruits of Dysoxylum densiflorum. The planar structures were elucidated by a combination of 1D, 2D NMR and HRESIMS analyses. Their absolute configurations were determined by combination of single-crystal X-ray diffraction, CD exciton chirality method and ECD calculation. All compounds were screened for anti-inflammatory activity on LPS-induced RAW 264.7 cells and IL-1β inhibitory activity.

Structurally diverse new eudesmane sesquiterpenoids with anti-inflammatory activity from the fruits of Alpinia oxyphylla

The phytochemical investigation of the fruits of Alpinia oxyphylla led to the isolation and identification of 40 structurally diverse sesquiterpenoids, including 17 new eudesmane sesquiterpenoids (1-17) and 23 known analogues (18-40). Among the isolates, 14 and 17 were unusual rearranged eudesmane sesquiterpenoids, featuring rare 5/6-fused and 6/8-fused bicyclic carbon skeleton, respectively; 15 and 16 were the novel 6,7-seco-eudesmane sesquiterpenoids isolated from plant-origin for the first time, 1 and 3-6 were rare nor-eudesmane sesquiterpenoids. Their structures were elucidated by comprehensive spectroscopic data analysis (NMR, HRESIMS, IR, UV), single crystal X-ray diffraction, and quantum chemistry calculations (ECD and ¹³C NMR). Moreover, all isolates were evaluated by measuring their inhibitory effect on nitric oxide (NO) in LPS-stimulated BV-2 cells. As a result, compounds 11, 20, 24 and 40 showed moderate to strong inhibition on NO productions, with IC₅₀ values ranging from 21.63 to 60.70 μM. Meanwhile, these compounds also partially decreased the secretion of TNF-α and IL-6 in LPS-stimulated BV-2 cells. Furthermore, 20 could down-regulate protein expressions (COX-2 and iNOS) and observably inhibit the mRNA expressions of TNF-α, IL-6, COX-2 and iNOS. In this study, the discovery of structurally diverse anti-inflammatory sesquiterpenoids from the fruits of A. oxyphylla could benefit the further development and utilization of this plant.

Structures, Occurrences and Biosynthesis of 11,12,13-Tri-nor-Sesquiterpenes, an Intriguing Class of Bioactive Metabolites

The compounds 11,12,13-tri-nor-sesquiterpenes are degraded sesquiterpenoids which have lost the C₃ unit of isopropyl or isopropenyl at C-7 of the sesquiterpene skeleton. The irregular C-backbone originates from the oxidative removal of a C₃ side chain from the C₁₅ sesquiterpene, which arises from farnesyl diphosphate (FDP). The C₁₂-framework is generated, generally, in all families of sesquiterpenes by oxidative cleavage of the C₃ substituent, with the simultaneous introduction of a double bond. This article reviews the isolation, biosynthesis and biological activity of this special class of sesquiterpenes, the 11,12,13-tri-nor-sesquiterpenes.

Noreudesmane sesquiterpenoids from Artemisia hedinii and their anti-inflammatory activities

Ten undescribed noreudesmane-type sesquiterpenoids, including eight 12,13-dinoreudesmanes and a pair of 11,12,13-trinoreudesmane epimers were isolated from the whole plant of Artemisia hedinii. Their structures were elucidated by extensive analysis of spectroscopic data, including MS, 1D and 2D NMR, and their absolute configurations were confirmed by X-ray diffraction experiments and DFT calculations. Compounds 1-5, 7-10 were evaluated for their anti-inflammatory activities in lipopolysaccharide (LPS)-stimulated murine macrophages RAW264.7 cells, and all of them could significantly inhibit the LPS induced CCL2 mRNA expression in a dose-dependent manner.

Eudesmane and Eremophilane Sesquiterpenes from the Fruits of Alpinia oxyphylla with Protective Effects against Oxidative Stress in Adipose-Derived Mesenchymal Stem Cells

Alpinia oxyphylla Miquel (Zingiberaceae) has been reported to show antioxidant, anti-inflammatory, and neuroprotective effects. In this study, two new eudesmane sesquiterpenes, 7α-hydroperoxy eudesma-3,11-diene-2-one (1) and 7β-hydroperoxy eudesma-3,11-diene-2-one (2), and a new eremophilane sesquiterpene, 3α-hydroxynootkatone (3), were isolated from the MeOH extract of dried fruits of A. oxyphylla along with eleven known sesquiterpenes (4–14). The structures were elucidated by the analysis of 1D/2D NMR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and optical rotation data. Compounds (1–3, 5–14) were evaluated for their protective effects against tert-butyl hydroperoxide (tBHP)-induced oxidative stress in adipose-derived mesenchymal stem cells (ADMSCs). As a result, treatment with isolated compounds, especially compounds 11 and 12, effectively reverted the damage of tBHP on ADMSCs in a dose-dependent manner. In particular, 11 and 12 at 50 µM improved the viability of tBHP-toxified ADMSCs by 1.69 ± 0.05-fold and 1.61 ± 0.03-fold, respectively.

Ethnopharmacological uses, phytochemistry, biological activities, and therapeutic applications of Alpinia oxyphylla Miquel: A review

ETHNOPHARMACOLOGICAL USAGES

Fructus Alpiniae oxyphyllae (A. oxyphylla) is an important medicinal plant that is used not only as an edible fruit, but also as an important traditional medicine for benefiting cognitive performance and alleviating a wide spectrum of diseases. Such as; warming kidney, securing essence and arresting polyuria, as well as warming the spleen and stopping diarrhea and saliva.

AIMS

The purpose of this review is to provide updated, comprehensive and categorized information on the traditional uses, phytochemistry and pharmacological research of A. oxyphylla in order to explore their therapeutic potential and establish a solid foundation for directing future research.

MATERIALS AND METHODS

All the available information on A. oxyphylla was collected via electronic search (using Pubmed, SciFinder, Scirus, Google Scholar and Web of Science) and additionally a number of unpublished resources, (e.g. books, Ph.D. and M.Sc. dissertations, government reports).

RESULTS

Phytochemical research on A. oxyphylla has led to the isolation of components such as essential oils, terpenes, diarylheptanoids, flavones, nucleobases and nucleosides, steroids and others. Crude extracts, fractions and phytochemical constituents isolated from A. oxyphylla showed a wide spectrum of in vitro and in vivo pharmacological activities like neuroprotective, anti-diarrheal, anti-diuretic, anti-neoplastic, anti-oxidant, anti-inflammatory, anti-allergic, viscera protective and anti-diabetic activities. Neuroprotective, anti-cancer, anti-diarrheal and anti-diuretic effects are major areas of research conducted on A. oxyphylla.

CONCLUSIONS

Modern pharmacological studies have supported many traditional uses of A. oxyphylla, including nervous system, urinary system and gastrointestinal system disease. There was convincing evidence in experimental animal models in support of its neuroprotection, secure essence, reduce urination, and anti-carcinogenic effects. However, all the reported pharmacological activities were carried out at pre-clinical level and the authors urge further investigation in clinical trials about these therapeutic fields of A. oxyphylla.

An overview of chemical constituents from Alpinia species in the last six decades

Alpinia species is one of the most important genera of the Zingiberaceae family. Up to 2015, 544 compounds with various bioactivities were isolated, the major components are diarylheptanoids (143) and sesquiterpenoids (132).