You-Xing Zhao

Five New Compounds from Dendrobium longicornu

A novel bibenzyl, a new bibenzyl, two new phenanthrenes, and a new lignin glycoside, namely longicornuol A (1), 4-[2-(3-hdroxyphenol)-1-methoxyethyl]-2,6-dimethoxyphenol (2), 5-hydroxy-7-methoxy-9,10-dihydrophenanthrene-1,4-dione (3), 7-methoxy-9,10-dihydrophenanthrene-2,4,5-triol (4) and erythro-1-(4-O-beta-D-glucopyranosyl-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2,6-dimethoxyphenoxy]-1,3-propanediol ( 5), together with 14 known compounds, were isolated from the stems of Dendrobium longicornu. All structures were elucidated by spectroscopic methods (NMR, MS, UV and IR). Anti-platelet aggregation activities of compounds 1 - 5 were also tested.

Meroterpenes from Endophytic Fungus A1 of Mangrove Plant Scyphiphora hydrophyllacea

Four new meroterpenes, guignardones F–I (1–4), together with two known compounds guignardones A (5) and B (6) were isolated from the endophytic fungus A1 of the mangrove plant Scyphiphora hydrophyllacea. Their structures and relative configurations were elucidated by spectroscopic data and single-crystal X-ray crystallography. A possible biogenetic pathway of compounds 1–6 was also proposed. All compounds were evaluated for inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus.

Anti-allergic prenylated hydroquinones and alkaloids from the fruiting body of Ganoderma calidophilum

Six new prenylated hydroquinones named ganocalidin A–F (1–6) and two new compounds of ganocalicine A (7) and B (8), together with sixteen known compounds (9–24) were isolated from an EtOAc extract of the fruiting body of Ganoderma calidophilum. The new compound structures were elucidated on the basis of spectroscopic data analysis including 1D, 2D NMR and MS. Compounds 1 and 7 showed inhibitory activity effects on β-hexosaminidase activity (IC50 9.44 and 9.14 μM, respectively), and significantly reduced the production of IL-4 and LTB4 by RBL-2H3 cells in response to antigen stimulation, suggesting that 1 and 7 possess anti-allergic activity.

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.

Cytotoxic and Antibacterial Flavonoids from Dragon's Blood of Dracaena cambodiana

Chemical studies on the constituents from the dragons blood of Dracaena cambodiana led to the discovery of three new flavonoid derivatives (1- 3) and six known compounds (4- 9). The structures of the three new compounds were elucidated by NMR and MS spectroscopic analyses. All compounds were evaluated for their growth inhibitory activity against human cell lines K-562, SMMC-7721, and SGC-7901, as well as antibacterial activities against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). As a result, compounds 1, 2, 5, 7, and 9 showed cytotoxicity against K-562, SMMC-7721, and SGC-7901 cell lines. All these compounds were observed to exhibit antibacterial activities against S. aureus, and compounds 1- 4, 6, 8, and 9 were observed to exhibit antibacterial activity against MRSA.

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.

Steroidal saponins from dragon's blood of Dracaena cambodiana.

Six new steroidal saponins, cambodianosides A-F (1-6), together with seven known ones, were isolated from the dragons blood of Dracaena cambodiana. The structures of 1-6 were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR techniques and chemical methods. The cytotoxicities of all the isolated compounds were evaluated in vitro against three human cancer cell lines, and compounds 7, 8, and 11 showed significant inhibitory activities.

Lanostane triterpenoids with cytotoxic activities from the fruiting bodies of Ganoderma hainanense

Twelve lanostane triterpenoids (1–12) including a new one 16α,26-dihydroxylanosta-8,24-dien-3-one (1) were isolated from the fruiting bodies of Ganoderma hainanense. The structure of the new compound was elucidated by 1D and 2D NMR and MS spectroscopic analyses. All isolates were evaluated for their cytotoxicities against human tumor cell lines K-562, SMMC-7721, and SGC-7901 and five compounds (1, 2, 5,7, and 9) showed definite cytotoxicities against K-562 cell line. Meanwhile, compounds 2, 5,7, and 9 exhibited cytotoxic activities against SMMC-7721 and SGC-7901 cell lines.

Lanostanoids with acetylcholinesterase inhibitory activity from the mushroom Haddowia longipes

Nine lanostanoids, together with nine known ones, were isolated from the ethyl acetate extract of the fruiting bodies of the mushroom Haddowia longipes. Their structures were elucidated as 11-oxo-ganoderiol D, lanosta-8-en-7,11-dioxo-3β-acetyloxy-24,25,26-trihydroxy, lanosta-8-en-7-oxo-3β-acetyloxy-11β,24,25,26-tetrahydroxy, lanosta-7,9(11)-dien-3β-acetyloxy-24,25,26-trihydroxy, lanosta-7,9(11)-dien-3β-acetyloxy-24,26-dihydroxy-25-methoxy, 11-oxo-lucidadiol, 11β-hydroxy-lucidadiol, lucidone H and lanosta-7,9(11),24E-trien-3β-acetyloxy-26,27-dihydroxy by analysing their 1D/2D NMR and MS spectra. In addition, bioassays of inhibitory activity against acetylcholinesterase (AChE) of all compounds showed that thirteen compounds possessed inhibitory activity against AChE with the percentage inhibition ranging from 10.3% to 42.1% when tested at 100 μM.