Steroids and dihydroisocoumarin glycosides from Xylaria sp. by the one strain many compounds strategy and their bioactivities / 中国天然药物

The fungus Xylaria sp. KYJ-15 was isolated from Illigera celebica. Based on the one strain many compounds (OSMAC) strategy, the strain was fermented on potato and rice solid media, respectively. As a result, two novel steroids, xylarsteroids A (1) and B (2), which are the first examples of C28-steroid with an unusual β- and γ-lactone ring, respectively, along with two new dihydroisocoumarin glycosides, xylarglycosides A (3) and B (4), were identified. Their structures were elucidated by spectroscopic methods, X-ray diffraction and electronic circular dichroism (ECD) experiments. All isolated compounds were evaluated for cytotoxicity, DPPH radical scavenging activity, acetylcholinesterase inhibitory and antimicrobial effect. Compound 1 exhibited potent AChE inhibitory activity with an IC50 value of 2.61 ± 0.05 μmol·L-1. The β-lactone ring unit of 1 is critical for its AChE inhibitory activity. The finding was further confirmed through exploring the interaction of 1 with AChE by molecular docking. In addition, both compounds 1 and 2 exhibited obvious antibacterial activity against Bacillus subtilis with a minimum inhibitory concentration (MIC) of 2 μg·mL-1. Compounds 3 and 4 exhibited antibacterial activities against Staphylococcus aureus with MICs of 4 and 2 μg·mL-1, respectively, which also exhibited DPPH radical scavenging activity comparable to the positive control with IC50 values of 9.2 ± 0.03 and 13.3 ± 0.01 μmol·L-1, respectively.

Coumarins from Skimmia arborescens and its anti-inflammatory effect / 中国中药杂志

To investigate chemical constituents contained in Skimmia arborescens. The chemical constituents were separated by silica gel column chromatography, pharmadex LH-20, RP-C18, and 1H, 13C-NMR spectroscopic analysis were employed for the structural elucidation. Six coumarin compounds were separated from S. arborescens. Their structures were elucidated as umbelliferone (1), scopoletin (2), scopolin (3), nodakenetin (4), skimmin (5), 6, 7-dimethoxycoumarin (6), and all compounds were separated from the plant for the first time. Using the model of ear swelling caused by xylol of mice, the anti-inflammatory effect of its total extract was evaluated. The result indicated that middle and high dose groups of its total extract could obviously inhibit the ear swelling caused by xylol of mice.

Chemical constituents from the seed coat of Juglans regia / 中国中药杂志

Fifteen compounds were isolated from the seed coat of Juglans regia by silica gel, MCI gel and Sephadex LH-20 gel column chromatography, as well as high preparative performance liquid chromatography. Their structures were identified as salidroside (1), (6S, 9S)-roseoside (2), (6S, 9R)-roseoside (3), blumenol C glucoside (4), byzantionoside B (5), 5-hydroxy-2-methoxy-1, 4-naphthoquinone (6), gallic acid (7), glycerol 1-(9Z-octadecenoate)-2-(9Z, 12Z-octadecadienoate)-3-(9Z, 12Z, 15Z-octadecatrienoate) (8), glycerol 1, 2, 3-tri-(9Z, 12Z-octadecadienoate) (9), glycerol 1, 2, 3-tri-(9Z, 12Z, 15Z-octadecatrienoate) (10), glycerol 1-hexadecanoate-2, 3-di-(9Z, 12Z-octadecadienoate) (11) on the basis of EI-MS, FAB-MS and NMR spectra. Moreover, 35 volatile compounds were identified by GC-MS.

Sesquiterpenes and an intermediate 1alpha, 6beta, 11-eudesmanetriol in the biosynthesis of geosmin from Streptomyces sp / 药学学报

One new sesquiterpene was isolated from the fermentation broth of Streptomyces sp. and the structure was elucidated by spectral analysis as caryolane-1, 6beta-diol (1). An intermediate 1alpha, 6beta, 11-eudesmanetriol (2) in the biosynthesis of geosmin was also found in this strain which proved sequence for the reactions, especially bicyclization preceding dealkylation.

Two diterpenoids from herbs of Huperzia serrata / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the constituents from Huperzia serrata.</p><p><b>METHOD</b>Two diterpenoid compounds were isolated by column chromatography with silica gel and Sephadex LH-20. The structures were elucidated by spectral analysis and X-ray crystallographic analysis.</p><p><b>RESULT</b>Their structures were determined as (15R)-12, 16-epoxy-11, 14-dihydroxy-8, 11, 13-abietatrien-7-one (1) and 3beta-hydroxysandaracopimaric acid (2).</p><p><b>CONCLUSION</b>Compound 1 was a new natural abietane-type diterpenoid, compound 2 was isolated from this plant for the first time.</p>

Two compounds from Drymaria diandra / 中草药

Objective To investigate the chemical costituents from Drymaria diandra. Methods Compounds were separated and purified by repeated column chromatographies on macroporous resin D101,silica gel, and RP-18.Two compounds were identified by spectral analysis. Results Two compounds were isolated from D. diandra. Theirs structures were identified as 6-carboxymethy1-5,7,4'-trihydroxyflavone (Ⅰ) and l-O-β-D-glucopyranosyl-(2S,3R,4E,8E)-Z-N-(2'-hydroxypalmitoyl) octadecasphinga-4,8-dienine(soya cerebroside Ⅰ,Ⅱ). Conclusion Compound I is a new compound. Compound Ⅱ is obtained from this plant for the frist time.