Geranyl phenyl ethers from Illicium micranthum and their anti-HBV activity.

Fourteen new geranyl phenyl ethers (1-14) along with three known compounds (15-17) were isolated from Illicium micranthum, and their structures were elucidated by comprehensive spectroscopic methods. Illimicranins A-H (1-8) were characterized as geranyl vanillin ethers, while 9 and 10 were dimethyl acetal derivatives. Illimicranins I and J (11 and 12) were rare geranyl isoeugenol ethers. Illimicranins K and L (13 and 14) represented the first example of geranyl guaiacylacetone ether and geranyl zingerone ether, respectively. Compounds 1, 2 and 15 exhibited anti-HBV (hepatitis B virus) activity against HBsAg (hepatitis B surface antigen) and HBeAg (hepatitis B e antigen) secretion, and HBV DNA replication.

Lignans and Neolignans with Antioxidant and Human Cancer Cell Proliferation Inhibitory Activities from Cinnamomum bejolghota Confirm Its Functional Food Property.

In the aim to evaluate the functional food property of Cinnamomum bejolghota, seven new lignans and neolignans, bejolghotins A-G (1-4 and 9-11), along with 14 known ones (5-8 and 12-21), were isolated and their structures including absolute configurations were elucidated by extensive spectroscopic data and electronic circular dichroism (ECD) analyses. All of the isolates were tested for antioxidant and human cancer cell proliferation inhibitory activities. Twenty compounds showed comparable antioxidant activity to the positive controls, and three significantly inhibited the growth of three cancer cell lines HCT-116, A549, and MDA-MB-231 with IC50 values of 0.78-2.93 µM, which confirmed its health benefits.

(±)-Meliviticines A and B: Rearranged prenylated acetophenone derivatives from Melicope viticina and their antimicrobial activity.

Two new prenylated acetophenone derivatives racemates, meliviticines A (1) and B (2) with unprecedented rearranged skeletons, were isolated from Melicope viticina. Subsequent chiral resolution led to the separation of two pairs of enantiomers, (±)-meliviticines A (1a/1b) and (±)-meliviticines B (2a/2b). Their structures including absolute configurations were elucidated by extensive spectroscopic data, electronic circular dichroism analysis, and X-ray crystallography. A plausible biosynthetic pathway of 1 and 2, involving ring cleavage and rearrangement of the prenylated acetophenone backbone was proposed. All the isolates showed moderate antimicrobial activities with MIC values of 25-50 µg/mL against several bacterial and fungal strains.

Cytotoxic arylalkenyl α,ß-unsaturated δ-lactones from Cryptocarya brachythyrsa.

Three new arylalkenyl α,ß-unsaturated δ-lactones, cryptobrachytones A-C (1-3), together with one known analogue kurzilactone (4), were isolated from the leaves and twigs of Cryptocarya brachythyrsa. Their structures were elucidated based on extensive spectroscopic data and electronic circular dichroism (ECD) analysis. All the isolates were evaluated in vitro for anti-proliferative activity against a panel of five human cancer cell lines and one human normal cell, respectively, and the results showed 1, 2 and 4 possessing significant selective cytotoxicity toward the human cancer cell lines with IC50 values from 5.41 to 15.43 µM. This is the first study for C. brachythyrsa.

Two spiroketal derivatives with an unprecedented amino group and their cytotoxicity evaluation from the endophytic fungus Pestalotiopsis flavidula.

Two new spiroketal derivatives with an unprecedented amino group, 2'-aminodechloromaldoxin (1) and 2'-aminodechlorogeodoxin (2), along with one known analogue dechloromaldoxin (3), were isolated from the plant endophytic fungus Pestalotiopsis flavidula. Their structures were elucidated on the basis of extensive spectroscopic analysis. The purification was cytotoxicity-guided which indicated the extract, fractions and compounds were evaluated in vitro for anti-proliferative activity against a panel of human cancer cell lines. The results showed compounds 1 and 2 with moderate cytotoxicity while 3 was inactive, which suggested -NH2 group might play a very important role for their cytotoxicity. This is the first study for P. flavidula and the first time to report the spiroketal derivatives as alkaloids from the Pestalotiopsis genus.