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In this work, we successfully explored an unexpected dehydrogenation triggered by Pd/Cu-catalyzed C(sp 3 )-H arylation and intramolecular C-N coupling of amides to synthesize the bioactive 1,2-dihydroquinoline scaffold with good regioselectivity and good compatibility of functional groups. This strategy provides an alternative route to realize molecular complexity and diversity from simple and readily available molecules via multiple C-H bond activation. Preliminary mechanistic studies demonstrated that β,γ-dehydrogenation is triggered by the arylation of the C(sp 3 )-H bond and the intramolecular C-N coupling.

In this letter, we successfully explored a cascade Pd/Cu-catalyzed intermolecular C(sp 3 )-H arylation of amides and intramolecular C-N coupling reaction. This method provides a one-pot strategy to synthesize 3,4-2 H-quinolinone with good regioselectivity of C-H arylation and C-N coupling from C-I and C-X bonds from readily available starting materials.

Human telomeric G-quadruplex is a four-stranded structure folded by guanines (G) via Hoogsteen hydrogen bonding. The ligands which stabilize the G-quadruplex are often telomerase inhibitors and may become antitumor agents. Here, the interaction between a lignan derivative liliflorin A and human telomeric sequence dGGG (TTAGGG)3G-quadruplex HTG21 were examined by CD, FRET, and NMR spectroscopic methods. In addition, Molecular Docking was used to study the binding of liliflorin A to dTAGGG (TTAGGG)3 G-quadruplex HTG23. The CD data showed that liliflorin A enhanced HTG21 T(m). The T(m) value of G-quadruplex was enhanced 3.2 degrees C by 4.0 μmol x L(-1) liliflorin A in FRET. The NMR spectra of HTG21 showed vivid alteration after reacting with liliflorin A in 3 hours. Molecular Docking suggested liliflorin A bound to the wide groove of HTG23 at G9, G10, G16 and G17. Liliflorin A was the first lignan derivative that could stabilize HTG21 selectively and provided a new candidate for antitumor drug design targeting on human telomeric G-quadruplex.

Chemical constituents from the acetone extract of twigs of Manglietia hookeri were isolated and purified by various column chromatographic methods over silica gel and sephadex LH-20, and preparative TLC. The structures of these compounds were identified on the basis of physicochemical properties and spectral analysis, including NMR and MS spectra. Six eudesmane sesquiterpenes were obtained and their structures were identified as trans-eudesmane-4, 11-diol(1), β-eudesmol(2), (-) -10-epi-5β-hydroxy-β-eudesmol (3), epi-carrisone (4), 6-hydroxy-eudesm-4(14) -ene(5) and gynurenol(6). All the compounds were isolated from this plant for the first time. Furthermore, the 13C-NMR data of compound 3 were reported for the first time.

The title compound, C(15)H(20)O(4), is a eudesmanolide isolated from the Chinese medicinal plant Carpesium tris-te Maxim. The mol-ecule contains three rings, viz. two fused six-membered rings in chair conformations and a five-membered ring in a flattened envelope conformation. In the crystal, two hy-droxy groups are involved in the formation of intra- and inter-molecular O-H⋯O hydrogen bonds. The H atoms in these groups are split, with site-occupation factors of 0.5. The inter-molecular hydrogen bonds link mol-ecules into chains propagating in [010].

Six new lignans, 1- 6, along with six known compounds were obtained from the flower buds of Magnolia liliflora Desr. The new lignans were elucidated as (1 S*,2 R*,5 S*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (1), (1 R*,2 R*,5 R*,6 S*)-2-(3,5-dimethoxyphenyl)-6-(3,4-methylenedioxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (2), (1 R*, 2 R*,5 R*,6 S*)-2,6-bis (3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane (3), (1 R*,2 S*,5 R*,6 R*)-2-(3,4-methylenedioxyphenyl)-6-(3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane ( 4), (7' S*,8 R*,8' R*)-3,5'-dimethoxy-3',4,9'-trihydroxy-7',9-epoxy-8,8'-lignan (5), and (7' R*,8' S*)-3,3',4,5'-tetramethoxy-7-en-7',9-epoxy-8,8'-lignan (6), by the analysis of 1D and 2D-NMR as well as HRESIMS data. The capacity of compound 1 to protect against damages to the DNA of rat lymphocyte cells induced by UV irradiation was assessed by the comet assay. It showed stronger antigenotoxicity than ascorbic acid from 6×10(-3) mmol·L(-1) to 6×10(-6) mmol·L(-1)., (© Georg Thieme Verlag KG Stuttgart · New York.)

The title eremophilenolide, C(15)H(22)O(3), is a natural compound isolated from Senecio laetus Edgew. The two cis-fused six-membered rings have chair confomations and the five-membered ring has a planar envelope conformation [maximum deviation = 0.010 (1) Å]. The β-hy-droxy group participates in inter-molecular O-H⋯O hydrogen bonding, forming mol-ecular chains along the a axis.

Objective: The study was to provided the reference for further development and utilization of Ligularia hodgsonii., Methods: The crude polysaccharide LW was extracted from Lugularia hodgsonii with hot water, and prectated by ethanol. The crude polysaccharide has been fractionted and purified, so LW21 was got. Its homogeneity was confirmed by chromatography on Sepharose CL-4B, paper chromatography and cellulous actate electrophoresis. The scavenging effets of the polysacehardes on * OH and O2-* were determined by fluorescence method., Results: Antioxidative experiment shows that LW and LW21 were effective in scavenging superoxide radical and hydroxyl radical. The scavenging capacity for superoxide radical and hydroxyl radical of LW21 had higher than that of LW., Conclusion: The polysaceharide from Ligularia hodgsonii had stronger antioxidant actioxdant activities, and their antioxidant activities had certain dose-relationship.

The title compound, C(18)H(26)O(7), is an eremophilenolide which has been isolated from the plant Ligularia duciformis for the first time. The present study confirms the atomic connectivity assigned on the basis of (1)H and (13)C NMR spectroscopy. The mol-ecule contains three fused rings, two six-membered rings in chair confomations and a five-membered ring in a flattened envelope conformation. Two hy-droxy groups are involved in formation of intra- and inter-molecular O-H⋯O hydrogen bonds. The latter ones link mol-ecules into chains propagating in [010].

Objective: To investigate the chemical constituents of Pteris multifida., Methods: All compounds were isolated and purified by normal column chromatography, paper thin layer chromatography and sephadex chromatography. The chemical structures were mainly elucidated by ESI mass and NMR spectra., Results: Seven compounds were isolated from the methanol extracts of Pteris multifida. In addition to a glycoside of sesquiterpene pterosin C-3-O-beta-D-glucoside(1), six flavonoids were isolated from S. barbata as fouows: apigenin(2), luteolin(3), apigenin-7-O-beta-D-glucoside(4), apigenin-7-O-beta-D-glucosyl-4'-O-alpha-L-rhanrnoside(5), apigenin-4'-O-alpha-L-rhanrnoside(6) and luteolin-7-O-beta-D-glucoside(7)., Conclusion: Compound(2), (3) and (5), (6) are isolated from Pteris multifida for the first time.

Objective: To study flavonoids in Scutellaria barbata and elucidate their structures., Method: Compounds were isolated and purified by normal column chromatography, paper thin layer chromatography and Sephadex chromatography. The chemical structures were elucidated by ESI mass and NMR spectra., Result: Five flavonoids were isolated from S. barbata and identified as apigenin (1), luteolin (2), ethyl-7-O-apigenin-glucuronate (3), apigenin-7-O-beta-glucoside (4), and apigenin-7-O-neohesperidoside (5), in addition to benzyaldehyde (6)., Conclusion: Flavonoidglycoside (3), (4) and (5) were isolated from S. barbata for the first time.

Five olean-12-ene triterpenes (1-5) were isolated from the whole plant of Ligulariopsis shichuana. Their structures were elucidated by spectroscopic methods, including IR, EIMS positive HRSIMS, 1DNMR, and 2DNMR. Among them, 16beta,28-dihydroxyolean-12-en-3-one (3), olean-12-en-3beta,6beta,16beta,28-tetraol (4), 6beta,16beta-dihydroxyolean-12-en-3-one (5) are new compounds. In addition, compounds 4 and 5 showed cytotoxic activities on human hepatomacells (SMMC-7721), human ovarian neoplasm cells (HO-8910) and human hepatocytes cells (LO2).

Two new diterpenes were isolated from Juniperus przewalskii, together with 17 known terpense. Their structures were elucidated by spectroscopic methods (IR, MS, 1H, 13C and 2DNMR). In addition, 3 alpha-hinokiol (3) and 3 alpha-hydroxymannol (9) exhibited effective antitumor activities to cervical carcinoma (HeLa) and human ovarian carcinoma (HO-8910) cell lines.