Secondary metabolites from the roots of Beilschmiedia tsangii and their anti-inflammatory activities

Two new sesquiterpenes from Xylopia vielana

Two new sesquiterpenes (1-2) and six known analogues (3-8) were isolated from the branches and leaves of Xylopia vielana Pierre. The structures of the new compounds were identified by analyzing 1 D and 2 D NMR data and HRESIMS data, combined with induced and calculated circular dichroism experiments. In addition, compounds 1-4, 7 and 8 showed notable nitric oxide (NO) inhibitory effects (IC₅₀ < 10 μM) on the model of the lipopolysaccharide (LPS)-activated RAW 264.7 macrophages.

Chemical characteristics of the sesquiterpenes and diterpenes from Lauraceae family and their multifaceted health benefits: A review

Lauraceae is a large family with significant economic and medicinal value. Bioactive ingredients from Lauraceae plants have contributed greatly to medicines, food nutrients and fine chemical products. In recent years, quite a few sesquiterpenes and diterpenes with unique structures have been achieved from Lauraceae and their potential benefits are embodied in a wide range of health areas. To our knowledge, there is no review to summarizes these constituents and their biological effects systematically. This current work aims to classify and ascribe the structural types and bioactivities of the identified sesquiterpenes and diterpenes. Herein, a total of 362 sesquiterpenes and 69 diterpenes were comprehensively complied. The various bioactivities could be recognized as cytotoxicity, anti-proliferation and/or anti-apoptosis, anti-inflammation, anti-oxidation, anti-bacterium, etc. This updated data could serve as a catalysis of these sesquiterpenes and diterpenes for the future medical and industrial applications.

Essential Oil and Major Non-Volatile Secondary Metabolites from the Leaves of Amazonian Piper subscutatum

The essential oil and the major non-volatile secondary metabolites from the leaves of Piper subscutatum (Miq.) C. DC. (Family Piperaceae), collected in the Ecuadorian Amazon, were analyzed for the first time in the present study. The essential oil was submitted to chemical and enantioselective analyses by GC-MS and GC-FID. (E)-β-caryophyllene (25.3-25.2%), β-chamigrene (10.3-7.8%), (E)-nerolidol (8.1-7.7%), β-selinene (7.2-7.7%), δ-cadinene (2.7-3.9%), bicyclogermacrene (3.7-2.4%), and β-pinene (2.6-3.4%) were the major components. The enantioselective analysis, carried out on a β-cyclodextrin-based column, showed four scalemic mixtures in which (1R,5R)-(+)-α-pinene, (1S,5S)-(-)-β-pinene, (S)-(-)-limonene, and (1R,2S,6S,7S,8S)-(-)-α-copaene were the major enantiomers, with enantiomeric excesses of 28.8%, 77.8%, 18.4%, and 6.0%, respectively. The study was complemented with the chemical analysis of the organic fraction dissolved in the hydrolate, whose major components were 6-methyl-5-hepten-2-one (63.7-64.4%) and linalool (6.5-6.0%). Concerning the non-volatile fraction, five lignans were the major components. (-)-Beilshminol B, (-)-grandisin, (-)-3',4'-methylenedioxy-3,4,5-trimethoxy-7,7'-epoxylignan, (-)-3',4'-methylenedioxy-3,4,5,5'-tetramethoxy-7,7'-epoxylignan, and (-)-3,4,3',4'-dimethylenedioxy-5,5'-dimethoxy-7,7'-epoxylignan were identified by means of NMR spectroscopy, mass spectrometry and X-ray crystallography. The absolute configuration 7S,8S,7'S,8'S was tentatively assigned to all of them.

Identification of Beilschmiedia tsangii Root Extract as a Liver Cancer Cell-Normal Keratinocyte Dual-Selective NRF2 Regulator

Transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) plays a crucial role in regulating the expression of genes participating in cellular defense mechanisms against oxidative or xenobiotic insults. However, there is increasing evidence showing that hyperactivation of NRF2 is associated with chemoresistance in several cancers, including hepatocellular carcinoma (HCC), thus making NRF2 an attractive target for cancer therapy. Another important issue in cancer medication is the adverse effects of these substances on normal cells. Here, we attempted to identify a dual-selective NRF2 regulator that exerts opposite effects on NRF2-hyperactivated HCC cells and normal keratinocytes. An antioxidant response element driven luciferase reporter assay was established in Huh7 and HaCaT cells as high-throughput screening platforms. Screening of 3,000 crude extracts from the Taiwanese Indigenous Plant Extract Library resulted in the identification of Beilschmiedia tsangii (BT) root extract as a dual-selective NRF2 regulator. Multiple compounds were found to contribute to the dual-selective effects of BT extract on NRF2 signaling in two cell lines. BT extract reduced NRF2 protein level and target gene expression levels in Huh7 cells but increased them in HaCaT cells. Furthermore, notable combinatory cytotoxic effects of BT extract and sorafenib on Huh7 cells were observed. On the contrary, sorafenib-induced inflammatory reactions in HaCaT cells were reduced by BT extract. In conclusion, our results suggest that the combination of a selective NRF2 activator and inhibitor could be a practical strategy for fine-tuning NRF2 activity for better cancer treatment and that plant extracts or partially purified fractions could be a promising source for the discovery of dual-selective NRF2 regulators.

New Anti-inflammatory Flavonol Glycosides from Lindera akoensis Hayata

Inflammation is related to many diseases. Lindera akoensis Hayata was often used in folktherapy in Taiwan for inflammation. In this study, three new flavonol acyl glycosides, namelykaempferol-3-O--D-4",6"-di-(E)-p-coumaroylglucoside (1), 3"-(E)-p-coumaroylafzelin (2) and 40-Omethyl-2",4"-di-(E)-p-coumaroylquercitrin (3), and three components, 3-dodecyl-4-hydroxy-5-methyldihydrofuran-2-one (4), 2-acetoxyclovan-9-ol (5), (1,4,6)-trihydroxyeudesmane(6) that were isolated from the natural product for the first time were obtained along with 25 knowncompounds from L. akoensis. Their structures were determined by comprehensive spectroscopicanalyses (1D and 2D NMR, EI-, ESI- and HRESI-MS). The ability of 1 to decrease the LPS-stimulatedproduction of nitrite in RAW264.7 cell was evaluated, showing an IC50 value of 36.3 ± 3.2 μM.This result supports the value of L. akoensis as a traditional medicine resource.

Unusual constituents from the medicinal mushroom Ganoderma lingzhi

Extensive studies have revealed that triterpenoids, meroterpenoids, and polysaccharides are the main constituents of the well-known traditional Chinese medicinal mushroom Ganoderma. In this study, we report seven previously undescribed sesquiterpenoids, including six gymnomitranes (1–6) and a novel type of sesquiterpenoid (8), together with a polyketide (7) and a known steroid (9) from the fruiting bodies of Ganoderma lingzhi, a fungus used as traditional medicine and food supplement in East Asia for ages. The structures of 1–8 were deduced by analysis of spectroscopic data, X-ray single crystal diffractions and TDDFT/ECD calculations. Compound 8 possessed an unusual 14(7→6)-cuparane scaffold. Compound 9 exhibited weak cytotoxicity against the five human cancer cell lines HL-60, MCF-7, SW480, A549, and SMMC-7721 with IC₅₀ values of 18.0–32.3 μM. A simple structure-activity-relationship (SAR) investigation by acetylating the 5-OH of 9 (9a) suggested that the 5-OH is essential for its cytotoxicity. Additionally, the biosynthetic pathways for compounds 2 and 8 are discussed.

Extensive studies have revealed that triterpenoids, meroterpenoids, and polysaccharides are the main constituents of the well-known traditional Chinese medicinal mushroom Ganoderma.

Chemical Structures of Lignans and Neolignans Isolated from Lauraceae

Lauraceae is a good source of lignans and neolignans, which are the most chemotaxonomic characteristics of many species of the family. This review describes 270 naturally occurring lignans and neolignans isolated from Lauraceae.

Divergent Diels-Alder Reactions in the Biosynthesis and Synthesis of Endiandric-Type Tetracycles: A Computational Study

Endiandric acids and related polyketide natural products arise from polyene precursors and occur naturally as fused and bridged tetracycles. In some cases, the intramolecular Diels-Alder reactions that produce fused and bridged tetracycles result from a diene tether that may act as either a 4π or 2π component in the cycloaddition. To examine the preference for fused or bridged products, we applied density functional theory (using the M06-2X and B3LYP functionals) to reactants with various substituents for both fused and bridged transition states. Fused products were generally preferred except when disfavored by extreme steric hindrance (e.g., a tert-butyl group). These computational results are consistent with experimental data and suggest the existence of as-yet undiscovered natural products.

Chemical Composition and Anti-phytopathogenic Activity of the Essential Oil of Beilschmiedia miersii

Beilschmiedia miersii (Gay) Kosterm. (Lauraceae) (“Belloto del Norte”) is a little-studied tree endemic of the Central Zone of Chile. Hydrodistillation of leaves and stem bark of B. miersii yielded 0.2% essential oil. GC-MS analysis allowed identification of 31 components. The most abundant compounds were three phenylpropanoids: Sarisan (45.8%), eugenol methyl ether (27.7%) and safrole (5.8%). The oil of B. miersii showed high antioxidant content (TEAC: 750.8 ± 9.6 μmol/100 g of essential oil). The anti-phytopathogenic activity was evaluated against pathogens of plants: Fungi (Botrytis cinerea, Gibberella fujikuroi and Phytophthora cinnamomi) and bacteria: (Erwinia carotovora, Pseudomonas syringae and Agrobacterium tumefaciens). The oil showed anti-phytopathogenic activity against all tested bacteria and fungi, especially against A tumefaciens (IC50 = 5 μg / mL) and P. cinnamomi (IC50 = 200 μg / mL). This study demonstrates that the essential oil of B. miersii has great potential for applications in food and agricultural industries.

Chemical constituents and bioactivity of Formosan lauraceous plants

Taiwan is rich in lauraceous plants. A review of 197 references based on the chemical analysis and bioactivity of indigenous lauraceous plants carried out by native scientists from 1963 to 2014 has been compiled. About 303 new compounds and thousands of known compounds comprising alkaloids and non-alkaloids with diverse structures have been isolated or identified from indigenous plants belonging to the 11 lauraceous genera. The volatile components, however, have been excluded from this review. This review provides an overview of the past efforts of Taiwan scientists working on secondary metabolites and their bioactivity in native lauraceous plants. The potential of lauraceous plants worthy of further study is also noted. The contents will be helpful for the chemotaxonomy of Lauraceae and be of value for the development of native Formosan lauraceous plants.

Endiandric Acid Derivatives and Other Constituents of Plants from the Genera Beilschmiedia and Endiandra (Lauraceae)

Plants of the Lauraceae family are widely used in traditional medicine and are sources of various classes of secondary metabolites. Two genera of this family, Beilschmiedia and Endiandra, have been the subject of numerous investigations over the past decades because of their application in traditional medicine. They are the only source of bioactive endiandric acid derivatives. Noteworthy is that their biosynthesis contains two consecutive non-enzymatic electrocyclic reactions. Several interesting biological activities for this specific class of secondary metabolites and other constituents of the two genera have been reported, including antimicrobial, enzymes inhibitory and cytotoxic properties. This review compiles information on the structures of the compounds described between January 1960 and March 2015, their biological activities and information on endiandric acid biosynthesis, with 104 references being cited.

Endiandric acid analogues from Beilschmiedia ferruginea as dual inhibitors of Bcl-xL/Bak and Mcl-1/Bid interactions

A rapid screening by (1)H and (1)H-(13)C HSQC NMR spectroscopy of EtOAc extracts of Endiandra and Beilschmiedia species allowed the selection of Beilschmiedia ferruginea leaves and flowers extract for a chemical investigation, leading to the isolation of 11 new tetracyclic endiandric acid analogues, named ferrugineic acids A-K (1-11). Their structures were determined by 1D and 2D NMR spectroscopic analysis in combination with HRMS data. These compounds were assayed for Bcl-xL and Mcl-1 binding affinities. Ferrugineic acids B, C, and J (2, 3, and 10) exhibited significant binding affinity for both antiapoptotic proteins Bcl-xL (Ki = 19.2, 12.6, and 19.4 μM, respectively) and Mcl-1 (Ki = 14.0, 13.0, and 5.2 μM, respectively), and ferrugineic acid D (4) showed only significant inhibiting activity for Mcl-1 (Ki = 5.9 μM).

Kingianic acids A-G, Endiandric acid analogues from Endiandra kingiana

A phytochemical investigation of the methanolic extract of the bark of Endiandra kingiana led to the isolation of seven new tetracyclic endiandric acid analogues, kingianic acids A–G (1–7), together with endiandric acid M (8), tsangibeilin B (9) and endiandric acid (10). Their structures were determined by 1D- and 2D-NMR analysis in combination with HRMS experiments. The structure of compounds 9 and 10 were confirmed by single-crystal X-ray diffraction analysis. These compounds were screened for Bcl-xL and Mcl-1 binding affinities and cytotoxic activity on various cancer cell lines. Compound 5 showed moderate cytotoxic activity against human colorectal adeno-carcinoma (HT-29) and lung adenocarcinoma epithelial (A549) cell lines, with IC₅₀ values in the range 15–17 µM, and compounds 3, 6 and 9 exhibited weak binding affinity for the anti-apoptotic protein Mcl-1.

Natural sesquiterpenoids

This review covers the isolation, structural determination, synthesis and chemical and microbiological transformations of natural sesquiterpenoids. The literature from January to December 2012 is reviewed, and 471 references are cited.