Synthesis and biological profiling of half-calycanthaceous alkaloid analogues.

During our continuous efforts to pursue antifungal agents, some calycanthaceous alkaloid analogs showed diverse and promising bioactivities. Therefore, 34 new calycanthaceous alkaloid derivatives were further prepared and screened for bioactivities. As a result of the evaluation against a great deal of plant pathogen fungi, bacteria and human pathogenic fungi, a majority of them displayed potent bioactivity. In particular, compound b6 displayed remarkably activity and might be novel potential leading compound for further development of antifungal agent. The relationship between structure and biological activity was also discussed.

Fischeriana A, a meroterpenoid with an unusual 6/6/5/5/5/6/6 heptacyclic carbon skeleton from the roots of Euphorbia fischeriana.

Fischeriana A (1), a new meroterpenoid with a rare carbon skeleton, along with one of its known biosynthesis-related compounds 2,4-dihydroxy-6-methoxyacetophenone (2) and two known ent-abietane-type diterpenoids (3-4), were isolated from the roots of Euphorbia fischeriana. Their structures, including the stereochemistry, were elucidated using comprehensive spectroscopic methods, single-crystal X-ray diffraction, and electronic circular dichroism analysis. Compound 1 was found to be made up of an unusual heptacyclic ring system (6/6/5/5/5/6/6) featuring a modified ent-abietane diterpene with a phloroglucinol moiety. A possible biogenetic pathway for 1 was proposed. Compound 1 exhibited marked anti-tumor activities against the HepG2 cell line.

Daturanolide A-C, Three New Withanolides from Datura metel L. and Their Cytotoxic Activities.

Three new withanolides (1-3), named as daturanolide A-C, along with six known withanolides (4-9) were isolated from the flowers of Datura metel L. Their structures with absolute configurations were elucidated by a series of spectroscopic methods, electronic circular dichroism (ECD) analyses, and X-ray crystallography. All the isolates were evaluated for cytotoxicity against five human cancer cell lines (HCT116, U87-MG, NCI-H460, BGC823, and HepG2), and 6 exhibited marked cytotoxicity.

Stelleratenoids A-F, macrocyclic daphnane orthoesters with anti-HIV activity from the roots of Stellera chamaejasme L.

Six undescribed macrocyclic daphnane orthoesters, stelleratenoids A-F (1-6), were isolated from the roots of Stellera chamaejasme L. Their structures were elucidated by extensive spectroscopic analyses, including HRESIMS and NMR spectra. Compound 1 features an unusual terminal double bond at C-2/C-19 in the 1α-alkyldaphnane lactone skeleton. Compounds 2-4 are unique in the presence of different long chain fatty acyl groups. Compounds 5 and 6 are unique examples of modified macrocyclic daphnane diterpenoids. All the isolates were evaluated for anti-HIV activity in MT-2 cells. Among them, compounds 1, 5 and 6 exhibited highly potent anti-HIV activity with EC50 values of 66.70, 10.62 and 55.10 nM, respectively, possessing high potential to develop new anti-HIV drugs.

Antioxidative, cytoprotective and whitening activities of fragrant pear fruits at different growth stages.

Pear is one of the most popular fruits in the world. With the fruit ripening, a series of physiological changes have taken place in fragrant pear, but up to now, the research on the metabolism and biological activity of phenolic compounds in different growth stages of fragrant pear is still lacking. In this study, four kinds of Xinjiang pears were selected as research objects, and the changes of phenolic content, antioxidant capacity, cell protection and whitening activity during fruit development were analyzed. The results showed that the phenolic content and antioxidant capacity of four pear varieties presented a decreasing trend throughout the developmental stages. The phenolic content and antioxidant activity of the four pears in the young fruit stage were the highest, and the active ingredients of the Nanguo pear were higher than the other three pear fruits. Pear extract could protect cells by eliminating excessive ROS in cells, especially in young fruit stage. The western blot results showed that the extract of fragrant pear in the young fruit stage could inhibit the expression of TYR, TYR1 and MITF in B16 cells, and it was speculated that the extract of fragrant pear in the young fruit stage might have good whitening activity. Therefore, the findings suggest that young pear display a good antioxidant potential and could have a good application prospect in food preservation and health product industry.

Two new sesquiterpenoids from endophytic fungus J3 isolated from Mangrove Plant Ceriops tagal.

Two new sesquiterpenoids, named 2α-hydroxyxylaranol B (1) and 4ß-hydroxyxylaranol B (2), together with a known diterpenoid 3,4-seco-sonderianol (3) were isolated from the fermentation of endophytic fungus J3 of Ceriops tagal. Their structures were elucidated based on spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY and HMBC). All compounds were evaluated for their cytotoxic activities by MTT method, and compound 3 exhibited cytotoxic activities against K562, SGC-7901, and BEL-7402 cell lines.