Chemical constituents from Dendrobium hainanense.

A new phenolic derivative (1) and a new dihydrophenanthrene (2) were isolated from the aerial part of Dendrobium hainanense rofe, along with 12 known compounds. The structures of the new compounds were elucidated by spectroscopic analysis，and the relative configuration of compound 1 was determined by J-based configuration analysis (JBCA) method. Bioassay result indicated that compound 1 exhibited weak antibacterial activity against Canidia albicans and Ralstonia solanaceanum.

Two new alkaloids from the twigs of Trigonostemon filipes.

A phytochemical investigation of the alkaloid constituents from Trigonostemon filipes Y. T. Chang et S. L. Mo led to the isolation of two new indole alkaloids, trigonostemine G (1) and trigonostemone J (2), together with two known ones, trigonostemine A (3) and trigonostemine B (4). Their structures were determined by extensive spectroscopic methods. Compounds 1-4 exhibited moderate AChE inhibitory activity with inhibition ratio of 31.6, 31.7, 41.7, and 42.4%, respectively. In addition, compounds 1-2 showed weak cytotoxicity against K562 and BEL-7402 human cancer cell lines.

A new steroidal saponin from dragon's blood of Dracaena cambodiana.

Phytochemical study on dragon's blood of Dracaena cambodiana led to a new steroidal saponin, cambodianoside G(1), and six known ones (2-7). The structure of the new compound was elucidated on the basis of detailed spectroscopic analysis. Evaluation of antibacterial activities showed that compound 7 exhibited antibacterial activity against Staphylococcus aureus.

Monoterpenoid coumarins from the peels of Clausena lansium.

A phytochemical investigation on the peels of Clausena lansium (Lour.) Skeels led to the isolation of two new monoterpenoid coumarins, named clauslactone V (1) and clauslactone W (2), together with three known analogues (3-5). Their structures were elucidated by spectroscopic techniques (UV, IR, MS, 1D and 2D NMR). All the compounds were evaluated for hypoglycemic activity, and compounds 1-5 showed α-glucosidase inhibitory activity in vitro.

A new lignan glycoside from Trigonostemon heterophyllus.

Phytochemical investigation on the stems of Trigonostemonheterophyllus led to the isolation of a new lariciresinol-based lignan glycoside, trigonoheteran (1), together with a known lignan glycoside, aviculin (2). Their structures were elucidated by spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY, HMBC, and NOESY).

Three new phenolic compounds from Dalbergia odorifera.

Three new phenolic compounds (1-3) were isolated from the heartwood of Dalbergia odorifera T. Chen. (Leguminosae). Their structures were established based on spectroscopic methods including 1D and 2D NMR (HSQC, COSY, HMBC and ROESY). Compound 2 exhibited cytotoxicity against BEL-7402 tumor cell lines.

2-(2-phenylethyl)chromone derivatives in Chinese agarwood "Qi-Nan" from Aquilaria sinensis.

Five new 2-(2-phenylethyl)chromone derivatives, qinanones A-E (1-5), together with eight known 2-(2-phenylethyl)chromone derivatives (6-13), were isolated from the Et2O extract of high-quality Chinese agarwood "Qi-Nan" originating from Aquilaria sinensis. The structures of the new 2-(2-phenylethyl)chromones were elucidated by spectroscopic techniques (UV, IR, 1D and 2D NMR) and MS analyses. In the bioassay for acetylcholinesterase inhibitors, compounds 1-6, 10, and 12 exhibited weak inhibitory activities (inhibition percentage ranged from 10 % to 24 % at the concentration of 50 µg/mL). Compared with other agarwoods, "Qi-Nan" was different in containing 2-(2-phenylethyl)chromones with unsubstituted chromone rings.

Two new acridone alkaloids from the branch of Atalantia buxifolia and their biological activity.

Two new acridone alkaloids, 3-methoxy-1,4,5-trihydroxy-10-methylacridone (1) and 2,3-dimethoxy-1,4,5-trihydroxy-10-methylacridone (2), were isolated from the ethanol extract of the branch of Atalantia buxifolia. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR. Compounds 1 and 2 exhibited significant antibacterial activity against Staphylococcus aureus and weak inhibitory effect on acetylcholinesterase.

A new antibacterial phenanthrenequinone from Dendrobium sinense.

A new phenanthrenequinone, named denbinobin B (1), together with three known phenanthrenes was isolated from the whole plant of Dendrobium sinense T. Tang et F.T. Wang, an endemic and endangered orchid to Hainan Island. The new compound was elucidated using a combination of 1D, 2D NMR (COSY, HMQC, and HMBC) techniques, and HR-ESI-MS analyses. Compound 1 exhibited moderate antibacterial activity against Staphylococcus aureus with the diameter of the inhibition zone of 16.5 mm.

Metabolites from the endophytic fungus Penicillium sp. FJ-1 of Ceriops tagal.

To investigate the chemical constituents of the endophytic fungus Penicillium sp. FJ-1 of Ceriops tagal, the chemical constituents were isolated by column chromatography on silica gel and Sephadex LH-20. Their structures were elucidated on the basis of spectroscopic analysis. Their antibacterial activity was tested by paper disco diffusion method. Two compounds were isolated and identified as 7-hydroxy-deoxytalaroflavone (1), and deoxytalaroflavone (2). Compound 1 is a new compound, and compounds 1 and 2 showed weak activity against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.

[Chemical constituents from stems of Aquilaria sinensis].

OBJECTIVE: To study the constituents from the stems of Aquilaria sinensis. METHOD: The chemical constituents were isolated by various column chromatographic methods. The structures were identified by spectral analysis including NMR and MS data. RESULT: Sixteen compounds were isolated and identified as threo-buddlenol C (1), thero-ficusesquilignan A (2), erythro-buddlenol C (3), (+/-) buddlenol D (4), (-) medioresinol (5), (-) pinoresinol (6), 5'-methoxy lariciresinol (7), erythro-guaiacylglycerol-beta-coniferyl ether (8), thero-guaiacylglycerol-beta-coniferyl ether (9), herpetin (10), (+) syringaresinol (11), curuilignan (12), ciwujiatone (13), coniferyl alcohol (14), 3, 4, 5-trimethoxyphenol (15) and cucurbitacin (16). CONCLUSION: All the compounds, except for 11-13 were obtained from A. sinensis for the first time.

Indole alkaloids from Kopsia hainanensis and evaluation of their antimicrobial activity.

Three new indole alkaloids, named kopsihainin D (1), kopsihainin E (2), and kopsihainin F (3), along with nine known compounds (4-12) were isolated from the twigs of Kopsia hainanensis. The structures of the new compounds were elucidated by spectroscopic methods including HRESIMS, UV, IR, and NMR. Compounds 1 - 3 and 5 showed inhibitory activity against Staphylococcus aureus with an antibacterial circle diameter of 11.2, 9.1, 10.3 and 9.7 mm, respectively.

A fatty acid glycoside from a marine-derived fungus isolated from mangrove plant Scyphiphora hydrophyllacea.

To study the antimicrobial components from the endophytic fungus A1 of mangrove plant Scyphiphora hydrophyllacea Gaertn. F., a new fatty acid glucoside was isolated by column chromatography from the broth of A1, and its structure was identified as R-3-hydroxyundecanoic acid methylester-3-O-α-l-rhamnopyranoside (1) by spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY and HMBC) and chemical methods. Antimicrobial assay showed compound 1 possessed modest inhibitory effect on Saphylococcus aureus and methicillin-resistant S. aureus (MRSA) using the filter paper disc agar diffusion method.

Metabolites from endophytic fungus A12 of Dracaena cambodiana.

A new drimane sesquiterpene, 1α,7α-dihydroxyconfertifolin (1), along with two known compounds 2 and 3, was isolated from endophytic fungus A12 of Dracaena cambodiana. The new compound was elucidated by HR-ESI-MS and spectroscopic techniques (IR, UV, 1D, and 2D NMR). Compound 2 showed inhibitory bacterial activity against Staphylococcus aureus with diameter of the inhibition zone of 13.5 mm.

A new tetranortriterpenoid from the roots of Atalantia buxifolia.

A new tetranortriterpenoid, named 6-deacetyl-severinolide, together with six known tetranortriterpenoids severinolide, acetyl-isoepiatalantin, 7-isovaleroylcycloepiatalantin, cycloepiatalantin, 7-isovaleroylcycloseverinolide, and atalantin, was isolated from the ethanol extract of the roots of Atalantia buxifolia collected in Hainan. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR (HMQC, ¹H-¹H COSY, HMBC, and NOESY).

Two new meroterpenes from endophytic fungus A1 of Scyphiphora hydrophyllacea.

Two new meroterpenes, guignardone D (1) and guignardone E (2), were isolated from endophytic fungus A1 of Scyphiphora hydrophyllacea Gaertn. F. Their structures were established based on spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY, HMBC, and ROESY).

Two new antimicrobial flavanes from dragon's blood of Dracaena cambodiana.

Two new flavonoids, named cambodianins D (1) and E (2), together with two known flavanes (2S)-7,4'-dihydroxy-6,8-dimethylflavane (3) and (2S)-7,3'-dihydroxy-4'-methoxy-8-methylflavane (4), were isolated from dragon's blood of Dracaena cambodiana. The new compounds were determined by HR-ESI-MS and spectroscopic techniques (UV, IR, 1D, and 2D NMR). Compounds 1-3 exhibited antimicrobial activities.

Two new triterpenoid saponins from the leaves of Ilex kudingcha.

Two new triterpene saponins, ilekudinchosides F (1) and G (2), along with three known saponins were isolated from the leaves of Ilex kudingcha C. J. Tseng. The new compounds were characterized as 3ß,19α-dihydroxy-12α-ethoxy-urs-13(18)-ene-28,20ß-lactone-3-O-[ß-D-glucopyranosyl(1 → 3)]-[α-L-rhamnopyranosyl(1 → 2)]-α-L-arabinopyranoside (1) and 3ß,19α-dihydroxy-12α-methoxy-urs-13(18)-ene-28,20ß-lactone-3-O-[α-L-rhamnopyranosyl(1 → 2)]-α-L-arabinopyranoside (2). The new structures were elucidated by spectroscopic methods including 1D and 2D NMR, HR-TOF-MS, and CD spectrometry, and the known compounds were identified by the comparison of their NMR and HR-TOF-MS data with those reported in the literature.

Triterpenes and triterpenoid saponins from the leaves of Ilex kudincha.

One new triterpene, kudinchalactone A (1), and four new triterpenoid saponins, ilekudinchosides A-D (2- 5), were isolated from the leaves of Ilex kudincha C. J. Tseng along with eight known triterpenoids. These new compounds were elucidated by spectroscopic methods including 1D and 2D NMR, HR-TOF-MS, and CD spectra. Compounds 2, 3, 12, and 13 showed antibacterial activities against Staphylococcus aureus (SA) and methicillin-resistant Staphylococcus aureus (MRSA).

Cytotoxic cardenolide glycosides from the seeds of Antiaris toxicaria.

Bioassay-guided fractionation of the ethanolic extract from the seeds of Antiaris toxicaria led to the isolation of three new cardiac glycosides named toxicarioside J, toxicarioside K, and toxicarioside L, together with a known glucostrophalloside. The structures of the new compounds were elucidated by spectroscopic methods including HRESIMS, UV, IR, and 1D, 2D NMR techniques. The cytotoxic activities of these cardiac glycosides against human gastric (SGC-7901) and human hepatoma (SMMC-7721) cell lines were evaluated, and all of them exhibited significant cytotoxicity.