Disentangling the chemistry of Australian plant exudates from a unique historical collection.

For thousands of years, the unique physicochemical properties of plant exudates have defined uses in material culture and practical applications. Native Australian plant exudates, including resins, kinos, and gums, have been used and continue to be used by Aboriginal Australians for numerous technical and cultural purposes. A historic collection of well-preserved native Australian plant exudates, assembled a century ago by plant naturalists, gives a rare window into the history and chemical composition of these materials. Here we report the full hierarchical characterization of four genera from this collection, Xanthorrhoea, Callitris, Eucalyptus, and Acacia, from the local elemental speciation, to functional groups and main molecular markers. We use high-resolution X-ray Raman spectroscopy (XRS) to achieve bulk-sensitive chemical speciation of these plant exudates, including insoluble, amorphous, and cross-linked fractions, without the limitation of invasive and/or surface specific methods. Combinatorial testing of the XRS data allows direct classification of these complex natural species as terpenoid, aromatic, phenolic, and polysaccharide materials. Differences in intragenera chemistry was evidenced by detailed interpretation of the XRS spectral features. We complement XRS with Fourier-transform infrared (FT-IR) spectroscopy, gas chromatography­mass spectrometry (GC-MS), and pyrolysis­GC-MS (Py-GC-MS). This multimodal approach provides a fundamental understanding of the chemistry of these natural materials long used by Aboriginal Australian peoples.

Volatile Oil of Platycladus Orientalis (L.) Franco Leaves Exerts Strong Anti-inflammatory Effects via Inhibiting the IκB/NF-κB Pathway.

This study was designed to investigate the anti-inflammatory effects of volatile oil of Platycladus orientalis (L.) Franco leaves (VOPF) and the underlying molecular mechanisms by using the non-infectious inflammation rat models and infectious inflammation mouse models. Ear swelling and intraperitoneal capillary permeability in mice, and carrageenan-induced toe swelling and cotton ball-induced granuloma in rats were used to reveal anti-inflammatory effects of VOPF. Moreover, the lipopolysaccharide (LPS)-induced mouse model of acute lung injury was used to explore the anti-inflammatory mechanism of VOPF. The results showed that VOPF could significantly inhibit auricular swelling, intraperitoneal capillary permeability in mice, and reduce granuloma swelling and paw swelling in rats. Furthermore, it significantly alleviated the pathological damage of the lung tissue. In addition, VOPF could reduce the contents of IL-1ß and TNF-α and increase the content of IL-10 in the serum. It had little effect on the expression of p65 but reduced the phosphorylation level of p65 and IκB in NF-κB pathway. In conclusion, VOPF has anti-inflammatory effects and the mechanisms involve the down-regulation of the phosphorylation levels of p65 and IκB and blockage of the NF-κB signaling pathway.

Andean Prumnopitys Andina (Podocarpacae) Fruit Extracts: Characterization of Secondary Metabolites and Potential Cytoprotective Effect.

The fruits from the Chilean Podocarpaceae Prumnopitys andina have been consumed since pre-Hispanic times. Little is known about the composition and biological properties of this fruit. The aim of this work was to identify the secondary metabolites of the edible part of P. andina fruits and to assess their antioxidant activity by means of chemical and cell-based assays. Methanol extracts from P. andina fruits were fractionated on a XAD7 resin and the main compounds were isolated by chromatographic means. Antioxidant activity was determined by means of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing power (FRAP), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. The cytoprotective activity of the extract against oxidative and dicarbonyl stress was evaluated in human gastric epithelial cells (AGS). The total intracellular antioxidant activity (TAA) of the extract was determined in AGS cells. The inhibition of meat lipoperoxidation was evaluated under simulated gastric digestion conditions. Rutin, caffeic acid ß-glucoside and 20-hydroxyecdysone were identified as major components of the fruit extract. Additional compounds were identified by high-performance liquid chromatography diode-array detector mass spectrometry (HPLC-DAD-MSn) and/or co-injection with standards. Extracts showed dose-dependent cytoprotective effects against oxidative and dicarbonyl-induced damage in AGS cells. The TAA increased with the pre-incubation of AGS cells with the extract. This is the first report on the composition and biological activity of this Andean fruit.