Three new metabolites, asperfumigatin (1), isochaetominine (10), and 8′-O-methylasterric acid (21), together with nineteen known compounds, were obtained from the culture of Aspergillus fumigatus, an endophytic fungus from the Chinese liverwort Heteroscyphus tener (Steph.) Schiffn. Their structures were established by extensive analysis of the spectroscopic data. The absolute configurations of 1 and 10 were determined by analysis of their respective CD spectra. Cytotoxicity of these isolates against four human cancer cell lines was also determined.

A chemical investigation of the endolichenic fungus Aspergillus versicolor (125a), which was found in the lichen Lobaria quercizans, resulted in the isolation of four novel diphenyl ethers, named diorcinols F–H (1–3, resp.) and 3-methoxyviolaceol-II (4), eight new bisabolane sesquiterpenoids, named (−)-(R)-cyclo-hydroxysydonic acid (5), (−)-(7S,8R)-8-hydroxysydowic acid (6), (−)-(7R,10S)-10-hydroxysydowic acid (7), (−)-(7R,10R)-iso-10-hydroxysydowic acid (8), (−)-12-acetoxy-1-deoxysydonic acid (9), (−)-12-acetoxysydonic acid (10), (−)-12-hydroxysydonic acid (11), and (−)-(R)-11-dehydrosydonic acid (12), two new tris(pyrogallol ethers), named sydowiols D (13) and E (14), and fifteen known compounds, 15–29. All of the structures were determined by spectroscopic analyses, and a number of them were further identified through chemical transformations and electronic circular dichroism (ECD) calculations. Preliminary bioassays of these isolates for the determination of their inhibitory activities against the fungus Candida albicans, and their cytotoxicities against the human cancer cell lines PC3, A549, A2780, MDA-MB-231, and HEPG2 were also evaluated.

Riccardin D, a liverwort-derived naturally occurring macrocyclic bisbibenzyl, has been found to exert anticancer effects in multiple cancer cell types. In this study, we investigated the effect and mechanism of Riccardin D on human breast cancer. Experiments were performed on human breast cancer MCF-7 and MDA-MB-231 cells. The antitumour effects of Riccardin D were assessed by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and human breast cancer xenografts mice model. TRAPeze^® XL Telomerase Detection assay was used for the detection of telomerase activity. γ-H₂AX foci formation was tested for the induction of DNA damage response. Cell cycle distribution was analysed by flow cytometry, and cell apoptosis was determined by annexin V-FITC/PI staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay and Western blotting. Riccardin D effectively inhibited the growth of MCF-7 and MDA-MB-231 cells in vitro. And Riccardin D also effectively delayed the growth of MCF-7 and MDA-MB-231-luc-D3H2LN xenografts without significant loss of body-weight. Further analysis suggested that Riccardin D's effects may arise from its suppression of telomerase activity, which led to telomere dysfunction. Telomerase inhibition and telomere dysfunction could activate the canonical ataxia telangiectasia-mutated (ATM) kinase-mediated DNA damage response, as shown by elevated expression of γ-H₂AX, p-ATM and p-Chk2. This is finally followed by the induction of cell cycle arrest and apoptosis, as shown by the increase of TUNEL-stained cells, caspase activation, PARP cleavage and the increase of bax/bcl-2 ratio. Moreover, Riccardin D induced p53-proficient MCF-7 cells to arrest in G1 phase and p53-deficient MDA-MB-231 cells to arrest in G2/M phase. Overall, these results demonstrate that Riccardin D may inhibit human breast cancer growth through suppression of telomerase activity.

Zedoardiol (1), a new furanoguaiane sesquiterpenoid, and 3,4-dihydroxybisabola-1,10-diene (2), a new naturally occurring bisabolane sesquiterpenoid, together with six known compounds, were isolated from Curcuma xanthorrhiza Roxb. Their structures were determined on the basis of comprehensive spectroscopic analyses, mainly 1D- and 2D-NMR, MS, IR and X-ray single-crystal diffraction. Herein, the isolation and structure elucidation of the compounds are described.

The first one-pot enantioselective oxidative coupling of cyclic benzylic ethers with aldehydes has been developed. A variety of benzylic ethers were transformed into the corresponding oxygen heterocycles with high enantioselectivity. Mechanistic experiments were conducted to determine the nature of the reaction intermediates. The application of this strategy to coupling reactions with other nucleophiles besides aldehydes was also explored.

Described is a practical and universal CH functionalization of readily removable N-benzyl and N-allyl carbamates, with a wide range of nucleophiles at ambient temperature promoted by Ph₃CClO₄. The metal-free reaction has an excellent functional-group tolerance, and displays a broad scope with respect to both N-carbamates and nucleophile partners (a variety of organoboranes and CH compounds). The synthetic utility in target- as well as diversity-oriented syntheses is demonstrated.

The first one-pot enantioselective oxidative coupling of cyclic benzylic ethers with aldehydes has been developed. A variety of benzylic ethers were transformed into the corresponding oxygen heterocycles with high enantioselectivity. Mechanistic experiments were conducted to determine the nature of the reaction intermediates. The application of this strategy to coupling reactions with other nucleophiles besides aldehydes was also explored.

Chemical investigation of the Chinese liverwort Scapania ciliata led to the isolation of four new cis-clerodane lactones, named ciliatolides A–D (1–4, resp.), among which compound 1 was found to be a tetranorclerodanoid. Their structures were determined by extensive analysis of spectroscopic data, and, in the case of compound 1, together with a single-crystal X-ray diffraction analysis. The absolute configurations were established by analysis of the CD spectra and by quantum-chemical CD calculations. The cytotoxicities of compounds 1–4 were preliminarily tested against the PC3 and MCF-7 cell lines.

Bioactivity-guided fractionation of the cytotoxic extract of Aspergillus niger, an endophytic fungus from the Chinese liverwort Heteroscyphus tener (Steph.) Schiffn., afforded five new naphtho-γ-pyrones, rubrofusarin-6-O-α-D-ribofuranoside (1), (R)-10-(3-succinimidyl)-TMC-256A1 (2), asperpyrone E (3), isoaurasperone A (4), and isoaurasperone F (5), as well as four known ones, dianhydroaurasperone C (6), aurasperone D (7), asperpyrone D (8), and asperpyrone A (9), together with a cytotoxic cyclic pentapeptide, malformin A₁ (10). Their structures were determined by extensive spectroscopic analysis. The absolute configurations of dimeric naphtho-γ-pyrones 3–9 were also determined by analysis of their respective CD spectra.

One undescribed 6,7-secofusicoccane-type diterpene, albifolione (1), and one new aromadendrane-type sesquiterpenoid ketone, methyl 2-oxoaromadendra-1(10),3-dien-12-oate (2), along with four known compounds, δ-cuparenol (3), fusicoauritone (4), chiloscyphenols A and B (5 and 6, resp.), were isolated from the liverwort Bazzania albifolia Horik. The structures and relative configurations of 1 and 2 were established unequivocally on the basis of spectroscopic data analysis. Preliminary bioassay revealed that compound 5 showed quite strong cytotoxicity against the human tumor cell line MCF-7, with an IC₅₀ value of 5.6 μM.

7′-Hydroxyriccardin C (1) and marchantin E (2), two macrocyclic bisbibenzyls with a stereogenic center at the ethylene bridge from Chinese liverworts, were investigated stereochemically. Compound 1 was found to be optically active and occurred as a pair of dynamically interchangeable atropisomers at room temperature due to the low barrier of rotation around the biaryl bond, while 2 was a racemic mixture, which was successfully resolved by chiral HPLC into two enantiomers. Their absolute configurations were unequivocally assigned by analysis of temperature-dependent NMR spectra, X-ray crystallographic diffraction, and comparison of experimental and calculated ECD data.

Four new phenolic glycosides, named rebouosides A–D (1–4, resp.), along with three known ones 2-(3,4-dihydroxyphenyl)ethyl 2-O-α-L-rhamnopyranosyl-β-D-allopyranoside (5), 2-(3,4-dihydroxyphenyl)ethyl β-D-allopyranoside (6), 2-(3,4-dihydroxyphenyl)ethyl β-D-glucopyranoside (7), and a nucleoside, inosine (8), were isolated from Chinese liverwort Reboulia hemisphaerica. Their structures were elucidated by acidic hydrolysis and extensive spectroscopic methods, including 2D-NMR techniques.

A new diterpene, (7α,11β,14β,16R)-7,11,14-trihydroxy-ent-kaur-15-one (1), and a new sesquiterpene, polyanthuslide (2), were isolated from the Chinese liverwort Chiloscyphus polyanthus. Their structures were determined on the basis of extensive spectroscopic analyses, and the configuration of 2 was established by X-ray crystallographic analysis.

Biotransformation of dihydroresveratrol by crude Momordica charantia peroxidase provided six new acyclic bis[bibenzyls] 1–6. Their structures were established on the basis of NMR and MS analyses as CC, COC, and CCH₂C dimers of dihydroresveratrol. Compounds 1–6 were tested for antiproliferative activity against human prostate cancer PC3 cell line in vitro, and 2 and 6 were found to be more potent than the parent compound.

Phytochemical investigation of the exudates of Commiphora opobalsamum led to the isolation of three new sesquiterpenoids, 2α-methoxy-6-oxogermacra-1(10),7(11)-dien-8,12-olide (1), 5β-10α-hydroxy-2α-methoxy-6-oxoguaia-7(11),8-dien-8,12-olide (2), and furanocadina-1(10),6,8-triene-4-ol (3), together with six known compounds. Their structures were elucidated on the basis of spectroscopic methods.