•Mono-functionalized copillar[5]arenes were synthesized.•Their rotation mode can be induced and controlled by mono-bulky substituent.•Conformational freedom depends on the size and length of substituent.•Their binding properties can be maintained as symmetrical pillar[5]arenes.Two types of copillar[5]arenes bearing mono-functionalized bulky substituents such as phenyl and naphthyl groups were synthesized and their conformational characteristics were studied by 1H NMR spectroscopy. Their rotation mode can be induced and controlled by the bulky substituents. The OCH3 groups on phenolic units, the same side as the bulky substituent, were rotating regularly in the mode of OR-opposite-the-annulus rotation while the mode of OR-through-the-annulus was seen for the other OCH3 groups on the other side. Furthermore, their excellent binding properties with 1,4-dibromobutane(DBB) can be maintained as the fully symmetrical pillar[5]arenes.

In an attempt to search for new natural products-based antifungal agents, a series of novel dehydroabietic acid derivatives bearing a 1,3,4-thiadiazole-thiazolidinone moiety were designed and synthesized. The primary bioassay used showed that at a concentration of \(50\,\upmu \hbox {g}/\hbox {mL}\), the target compounds 3c, 3f, and 3n exhibited excellent antifungal activity (91.3 % inhibition) against Gibberellazeae, which was equivalent to the commercial antifungal drug azoxystrobin (positive control).

In an attempt to search for natural product-based insecticidal agents, a series of novel dehydroabietic acid derivatives bearing 1,3,4-thiadiazole moiety were designed and synthesized. Their structures were characterized by IR, MS, 1H-NMR, 13C-NMR, and elemental analysis. The insecticidal activities against cotton bollworm (Helicoverpa armigera), corn borer (Ostrinia nubilalis Hübner), and diamondback moth (Plutella xylostella (L.)) were evaluated. The bioassay test showed that some of the target compounds exhibited excellent insecticidal activities at the concentration of 200 µg/ml; compound 3a had the best mortality rate of 90.0 and 80.0 % against H. armigera and O. nubilalis Hübner, respectively.

A new type of cellulose derivative, cellulose dehydroabietate (CDA), was synthesized by the O-acylation reaction of cellulose with dehydroabietic acid chloride (DHAC) using ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) as a solvent and 4-dimethyl-aminopyridine (DMAP) as a catalyst. The resulting CDA was characterized by means of FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and elemental analysis. Also, some properties of CDA were determined. These results showed that CDA has better solubility, water-repellency, and resistance to acids and bases than raw cellulose, and these properties increase with the DS of CDA.Graphical abstractCellulose dehydroabietate (CDA), a new type of cellulose derivative, was synthesized by the O-acylation reaction of cellulose with dehydroabietic acid chloride (DHAC) using ionic liquid 1-butyl-3-methylimidazolium bromide ([bmim]Br) as a green reaction solvent. CDA with high DS value has potential applications in the field of water barrier and hydrophobic material.Highlights► Cellulose dehydroabietate (CDA)—a new type of cellulose derivative was synthesized. ► Ionic liquid [bmim]Br was used as an effective green reaction solvent. ► CDA has better solubility, water-repellency and the resistance to acids and bases. ► These properties increase with the degree of substitution of CDA.

A new type of chitosan derivative, dehydroabietic acid-modified chitosan (DAMC), was synthesized by the acylation reaction of chitosan with dehydroabietic acid chloride (DHAC) under microwave irradiation. The resulting product (DAMC) was characterized by FT-IR, UV, 1H NMR, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and elemental analysis. The degree of substitution (DS) of DAMC was 16.5%. And chitosan and DAMC were used as carriers of fenoprofen calcium (FC), and their controlled release behavior in artificial intestinal juice was studied. The results showed that the controlled release of FC from the carrier of DAMC is better than that from original chitosan.

In the presence of the ionic liquid [bmim]Br/AlCl3 as green reaction medium, methyl 12-benzoyldehydroabietate was synthesized through Friedel-Crafts acylation reactions on the aromatic ring of methyl dehydroabietate. The optimum synthetic conditions of the target product were found to be as follows: molar ratio of methyl dehydroabietate to [bmim]Br to AlCl3 to benzoyl chloride 1:4:8:8, reaction temperature 40°C, reaction time 2 h. The target product was analyzed and characterized by means of IR, MS, NMR and elemental analysis. The results show that this novel method has the advantages of mild condition, short reaction time and environmental benignity.