Six novel lactone derivatives, cryptolaevilactones A-F (1-6), were isolated from Cryptocarya laevigata. Their unique spiro[3.5]nonane moiety by hetero [2 + 2] cyclization with monoterpene and polyketide was found for the first time in nature. Structural elucidation using various nuclear magnetic resonance (NMR) techniques revealed that 1-3 and 4-6 are diastereomers and partially established the absolute configurations.

While intensive efforts are made to prepare carbon fiber reinforced plastics from renewable sources, less emphasis is directed towards elaborating green approaches for carbon fiber surface modification to improve the interfacial adhesion in these composites. In this study, we covalently attach lignin, a renewable feedstock, to a graphitic surface for the first time. The covalent bond is established via aromatic anchoring groups with amine functions taking part in a nucleophilic displacement reaction with a tosylated lignin derivative. The successful grafting procedures were confirmed by cyclic voltammetry, X-ray photoelectron spectroscopy, and field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. Both fragmentation and microdroplet tests were conducted to evaluate the interfacial shear strength of lignin coated carbon fiber samples embedded in a green cellulose propionate matrix and in a commercially used epoxy resin. The microdroplet test showed ~27% and ~65% increases in interfacial shear strength for the epoxy and cellulose propionate matrix, respectively. For the epoxy matrix covalent bond, it is expected to form with lignin, while for the cellulosic matrix hydrogen bond formation might take place; furthermore, plastisizing effects are also considered. Our study opens the gates for utilizing lignin coating to improve the shear tolerance of innovative composites.

Carbon fiber reinforced composites have exceptional potential to play a key role in the materials world of our future. However, their success undoubtedly depends on the extent they can contribute to advance a global sustainability objective. Utilizing polymers in these composites that can be potentially derived from biomasses would be certainly vital for next-generation manufacturing practices. Nevertheless, deep understanding and tailoring fiber-matrix interactions are crucial issues in order to design carbon fiber reinforced sustainable resource-based biocomposites. In this study, cellulose derivatives (cellulose propionate and cellulose acetate butyrate) are utilized as model polymer matrices that can be potentially fabricated from biomasses, and the mechanical properties of the prepared short carbon fiber reinforced composites are engineered by means of a functional biobased lignin coating on the fiber surface. Furthermore, polyamide 6 based composites are also prepared, the monomer of this polymer could be obtained using C6 sugars derived from lignocellulosic biomasses in the future (through 5-hydroxymethylfurfural). Lignin was successfully immobilized on the carbon fiber surface via an industrially scalable benign epoxidation reaction. The surface modification had a beneficial impact on the mechanical properties of cellulose propionate and polyamide 6 composites. Furthermore, our results also revealed that cellulose-based matrices are highly sensitive to the presence of rigid fiber segments that restrict polymer chain movements and facilitate stress development. It follows that the physicochemical properties of the cellulosic matrices (molecular weight, crystallinity), associated with polymer chain mobility, might need to be carefully considered when designing these composites. At the same time, polyamide 6 showed excellent ability to accommodate short carbon fibers without leading to a largely brittle material, in this case, a maximum tensile strength of ~136 MPa was obtained at 20 wt% fiber loading. These results were further contrasted with that of a petroleum-based polypropylene matrix exhibiting inferior mechanical properties. Our study clearly indicates that carbon fiber reinforced polymers derived and designed using biomass-derived resources can be promising green materials for a sustainable future.

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A new chromone, 2-(2-hydroxy-2-phenylethyl)chromone (), was isolated together with ten known phenylethyl chromones from MeOH extracts of agarwood (). The selected compounds were evaluated in an antiproliferative assay against five human tumor cell lines, including a multidrug-resistant cell line. They were also tested for antitumor promoting activity, as mediated by 12--tetradecanoylphorbol-13-acetate-induced activation of the Epstein-Barr virus early antigen in Raji cells. Among all compounds, 4',7-dimethyoxy-6-hydroxychromone () displayed broad spectrum antiproliferative activity against all tumor cell lines tested with IC values of 25-38 µM, while was selectively inhibitory against multidrug-resistant cells. All tested compounds suppressed tumor promotion at noncytotoxic concentrations. 4',6-Dihydroxyphenylethylchromone () exhibited the most potent effect with an IC value of 319 mol ratio relative to 12--tetradecanoylphorbol-13-acetate. This study is the first to report the antitumor promoting activity of 2-(2-phenylethyl)chromone derivatives, as well as the selective antiproliferative activity of against a multidrug-resistant tumor cell line.