| Polar has a unique climate and geographical features,perennial light radiation,covered by snow and ice.Seasonal light time,the cold climate gives the polar microbiological special biological characteristics.Polar microbial resources are novel and diverse in terms of scientific research and application development and other fields are of great significance,and gradually by domestic and foreign researchers attention.The study of resource utilization and active chemical composition of polar microbes has also become one of the hotspots in the international microbiology.In the previous study,our group selected a variety of cytotoxic activity of the polar marine fungi Aspergillus sp.S-3-62 and Geomyces sp.3-1,Based on this background,the chemical constituents of the fermentation products of fungi S-3-62 and 3-1 were studied.The strain Aspergillus sp.S-3-62 attempted to explore the fermentation medium by changing the fermentation medium using the OSMAC strategy.Under the same culture conditions,five different media were selected.The optimum fermentation conditions were obtained by comparing the p H value of the fermentation end point,the dry weight of mycelia,the total extract weight of the fermentation broth,and the total extract composition(TLC and HPLC-UV).The optimum culture conditions were Aspergillus sp.S-3-62: 24 ?C,inoculation amount 10 %,rotation speed 120 r/min,shaking 8 d,using CYA(liquid)The strain Aspergillus sp.S-3-62 was fermented 350 L at the optimized conditions.After the fermentation,the fermentation broth was centrifuged at high speed,and the mycelia and Fermentation broth were obtained.The Fermentation broth were extracted 3 times with equal volume of butyl acetate.(90 min / time),the extract was concentrated to no organic solvent,mixed with water and extracted with ethyl acetate.The mycelia were extracted with ethanol for two times.Extract about 8 g.By comparing the crude extracts of the crude TLC layer of the fermentation broth solution,it was found that the crude extract of the two extracts was basically the same,and the extract was combined to obtain the total extract of about 50 g.The strain Geomyces sp.3-1: Bottle fermentation of the total fermentation of 42 L,with the same method of S-3-62.Because the TLC spots was similar,we obtained the combined extract in a total of 9.3 g of Geomyces sp.3-1.The chromatographic techniques were carried out by silica gel column chromatography,ODS reverse phase silica gel column chromatography,gel column chromatography and high performance liquid chromatography.Finally,more than 30 monomeric compounds were obtained.The structure of 18 compounds was identified by means of high resolution mass spectrometry and nuclear magnetic resonance(1D-NMR 2D-NMR),and the structures were as follows: ?-carboline(1),N-(2-Hydroxypropanoyl)-2-aminobenzoic acid amide(2),Cyclo-(Pro-8-hydroxy-Ile)(3),Cyclo-(Pro-Ile)(4),2-Acetyl-4(3H)-quinazolinone(5),4-Hydroxybenzaldehyde(6),Benzeneacetic acid,2-hydroxy-1-methylpropyl ester(7),Palitantin A(8),Palitantin B(9),Palitantin(10),Paulownin(11),Demethylincisterol A3(12),Ergosta-7,22-dienen-3,6-dione(13),Citreoanthrasteroid B(14),19-Norergosta-5,7,9,22-tetraene-3?-ol(15),(22E)-5?,8?-Epidioxyergos ta-6,22-dien-3?-ol(16),(3?,5?,6?,22E)-6-Methoxyergosta-7,22-diene-3,5-diol(17)and Ergosta-7,22-dien-3?-ol(18).Compounds 8 and 9 are new compounds,compound 7 is a new natural product,and compound 12-17 were isolated from polar Geomyces sp.for the first time.These compounds were tested against antibacterial,cytotoxic and PTP-1B.The results showed that compounds 10,11 and 12 had strong PTP-1B inhibitory activity,IC50 were 23.74 ± 0.43,34.32 ± 0.28 and 17.24 ± 0.28 ?M,respectively.The positive control oleanolic acid IC50 was 8.31 ± 0.31 ?M.Compound 12 showed better inhibition of cell proliferation in human gastric cancer cell 7901 and human hepatoma cell 7721 with IC50 of 13.94 ± 0.33 and 11.40 ± 0.41(IC50 of paclitaxel was 1.59 ± 0.25 and 0.36 ± 0.10,respectively);The results of antibacterial activity showed that compound 12 had a strong inhibitory effect on Escherichia coli,Bacillus subtilis and Methicillin-resistant Staphylococcus aureus(MRSA),with MIC of 7.79 ?M,7.79 ?M and 9.97 ?M,respectively,while the rest compounds only have weak inhibition.The chemical structure of 18 compounds were as follows:... |
PDF Full Text Request