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[en] The Andes-endemic Barnadesioideae lineage is the oldest surviving and phylogenetically basal subfamily of the Asteraceae (Compositae), a prolific group of flowering plants with world-wide distribution (∼24,000 species) marked by a rich diversity of sesquiterpene lactones (STLs). Intriguingly, there is no evidence that members of the Barnadesioideae produce STLs, specialized metabolites thought to have contributed to the adaptive success of the Asteraceae family outside South America. The biosynthesis of STLs requires the intimate expression and functional integration of germacrene A synthase (GAS) and germacrene A oxidase (GAO) to sequentially cyclize and oxidize farnesyl diphosphate into the advanced intermediate germacrene A acid leading to diverse STLs. Our previous discovery of GAO activity conserved across all major subfamilies of Asteraceae, including the phylogenetically basal lineage of Barnadesioideae, prompted further investigation of the presence of the gateway GAS in Barnadesioideae. Herein we isolated two terpene synthases (BsGAS1/BsGAS2) from the basal Barnadesia spinosa (Barnadesioideae) that displayed robust GAS activity when reconstituted in yeast and characterized in vitro. Despite the apparent lack of STLs in the Barnadesioideae, this work unambiguously confirms the presence of GAS in the basal genera of the Asteraceae. Phylogenetic analysis reveals that the two BsGASs fall into two distinct clades of the Asteraceae's GASs, and BsGAS1 clade is only retained in the evolutionary closer Cichorioideae subfamily, implicating BsGAS2 is likely the ancestral base of most GASs found in the lineages outside the Barnadesioideae. Taken together, these results show the enzymatic capacities of GAS and GAO emerged prior to the subsequent radiation of STL-producing Asteraceae subfamilies. - Highlights: • Sesquiterpene lactones are characteristic metabolites in Asteraceae family. • Barnadesioideae is the basal lineage of all Asteraceae plants, producing sesquiterpene lactones. • Two germacrene A synthases (GASs) were identified and characterized from Barnadesia spinosa. • A phylogenetic analysis showed two sub-clades of GASs have evolved in Asteraceae. • GAS enzymes evolved prior to the divergence and global dispersal of the modern Asteraceae.
[en] Highlights: • Large size and high quality MAPbI3 crystal grown from γ-butyrolactone. • An order enhanced photocurrents was observed on (112) plane. • (112) plane was more excellent in optoelectronic performances than (100) plane.
[en] Herein, poly(ε-caprolactone) (PCL) mats with different amounts of nanohydroxyapatite (nHAp) were produced using rotary-jet spinning (RJS) and evaluated in vitro and in vivo. The mean fiber diameters of the PCL, PCL/nHAp (3%), PCL/nHAp (5%), and PCL/nHAp (20%) scaffolds were 1847 ± 1039, 1817 ± 1044, 1294 ± 4274, and 845 ± 248 nm, respectively. Initially, all the scaffolds showed superhydrophobic behavior (contact angle around of 140oC), but decreased to 80° after 30 min. All the produced scaffolds were bioactive after soaking in simulated body fluid, especially PCL/nHAp (20%). The crystallinity of the PCL scaffolds decreased progressively from 46 to 21% after incorporation of 20% nHAp. In vitro and in vivo cytotoxicity were investigated, as well as the mats’ ability to reduce bacteria biofilm formation. In vitro cellular differentiation was evaluated by measuring alkaline phosphatase activity and mineralized nodule formation. Overall, we identified the total ideal amount of nHAp to incorporate in PCL mats, which did not show in vitro or in vivo cytotoxicity and promoted lamellar bone formation independently of the amounts of nHAp. The scaffolds with nHAp showed reduced bacterial proliferation. Alizarin red staining was higher in materials associated with nHAp than in those without nHAp. Overall, this study demonstrates that PCL with nHAp prepared by RJS merits further evaluation for orthopedic applications. .
[en] Garcinia mangostana Linn,(Family; Guttiferae) is known to be a rich source of bioactive molecules including flavonoids, benzophenones and lactones. A variety of xanthones have been isolated from mangosteen plants and fruits include the hull, rind heartwood and flesh. The fruit hull is used as an astringent and also used against cholera, dysentery and diarrhoea in traditional medicinal system. Petroleum ether extraction of the dried and powered fruit hulls followed by column chromatographic separation afforded two compounds, namely, gartanin (1) (0.48% in yield, mp 146-152 ) and mangostin (2) (0.97% in yield, mp (179-180). The structures of these two compounds have been identified by UV, FT-IR, NMR and EIMS. These identifications were confirmed by comparison of melting point values with reported data in the literature
[en] Recent advances in the synthesis of macrocycles with musk scent via catalytic olefin metathesis are presented with a particular emphasis on advantages offered by the metathesis technology. The review includes short historical background about musks and olefin metathesis to introduce the subject. Substantial emphasis is given on ring-closing metathesis (RCM) as a tool for the synthesis of cyclic compounds such as civetone, muscone, exaltolide, ambrettolide/isoambrettolide, and yuzu lactone. The bibliography includes 106 references. (paper)