Study On Bioactive Secondary Metabolites Of Bipolaris Sorokiniana A606 And Diaporthe Longicolla A616, The Endophytic Fungi From Pogostemon Cablin

Pogostemon cablin is a traditional folk medicinal plants with significant local characteristics, can be used for treat dampness in the resistance, Shushi fatigue, chest discomfort, cold summer closure, diarrhea, abdominal pain and headache Biyuan. For Patchouli, researching focus on the chemical composition and pharmacological activities of medicinal herbs, while studing the activity of endophytic fungi and their metabolites has been reported rarely.Endophytes are the chemical synthesizers inside plants. The secondary metabolites produced by endophytes associated with medicinal plants can be exploited for curing many diseases. The various natural products produced by endophytic fungi possess unique structures and bioactivities, thus representing a huge reservoir which offers an enormous potential for exploitation in agricultural and industrial areas.By screening fermentation crude extract cytotoxicity of SF-26, MCF-7, NCI-H460, and Hep G-2 for the endophytic fungus Bipolaris sorokiniana A606 and Diaporthe longicolla A616, which were isolated from the medicinal plant Pogostemon cablin, the crude extracts inhibited the growth rate 91.1%, 88.9%, 85.6%, 82.5%, and 92.3%, 82.8%, 882.8, 69.1% in the concentration 100g/m L, respectively.29 compounds(see Fig.1 and Fig.2) were isolated from the culture extracts of strains Bipolaris sorokiniana A606 and Diaporthe longicolla A616 by repeated column chromatography(CC) on silica gel, RP-18, Sephadex LH-20, HPLC, preparative thin layer chromatography(PTLC), and recrystallization and so on. The structures of these compounds were elucidated by means of spectroscopic techniques, including ESI-MS, HR-ESI-MS, 1D-NMR(1H-NMR, 13 C-NMR, DEPT) and 2D-NMR(1H-1H COSY, HSQC, HMBC, NOESY) as well as chemical method.19 compounds were isolated from A606 and identified as isocochlioquinones D-E(1-2), cochlioquinones G-I(3-5), isocochlioquinone C(6), cochlioquinone C(7), cochlioquinone D(8), cochlioquinone E(9), cochlioquinone B(10), precochlioquinol D(11),(22E,24R)-ergosta-4,6,8(14)-22-tetraen-3-one(12), 2-[4-(2-aminoethoxy)phenyl]ethanol(13), Di-(2-ethylhexyl)phthalate(14), 5-(hydroxymethyl)furan-2-carbaldehyde(15), 3,5-Dihydroxytoluene(16), 2-(4-Hydroxyphenyl)ethanol(17),(5-methylfuran-2-yl)methanol(19), 3,4,6-trimethylcyclohex-3-en-1-ol(19). 10 compounds were isolated from A616 and identified as 1,3-diamino-1,3-dimethylurea(20),(7R,9R)-7-hydroxy-9-propyl-5-nonen-9-olide(21), Ergosta-5,7,22-trien-3β-ol(22),(22E,24R)-ergosta-4,6,8(14)-22-tetraen-3-one(23),(22E,24R)-3β,5α-Dihydroxy-6β-ergosta-7,22-diene(24), citreoisocoumarin(25), glycerol monolinoleate(26), 1-(2-hydroxyethoxy)ethyl(E)-octadec-9-enoate(27), cyclo-(L-Pro-L-Ala)(28), cyclo(L)-Pro-(L)-Val(29). Compounds 1-10 are a series of cochlioquinones derivatives. Compounds 1-5 are new compounds. Compounds 12-15 and 18-19 were obtained from Bipolaris genus for the first time. Compounds 25-29 were isolated from Diaporthe genus for the first time.These compounds were preliminary evaluated for their cytotoxic by the SRB assay. The results indicated that compounds 3-4, 7-10 and 23-24 showed strong cytotoxicity against SF-26, MCF-7, NCI-H460, and Hep G-2. Compound 3 showed cytotoxic activity against tumor cell line Hep G-2 with IC50 values of 11.3 μM. Compound 4 showed cytotoxic activity against four tumor cell lines SF-268, MCF-7, NCI-H460 and Hep G-2 with IC50 values of 6.4, 8.6, 15.5, 7.6 μM, respectively. Compounds 7-10 showed cytotoxic activity against three tumor cell lines SF-26、MCF-7 and Hep G-2 with IC50 values of 1.2-13.1 μM. Compounds 23 and 24 showed cytotoxic activity against four tumor cell lines with IC50 values of 5.3, 6.5, 12.2, 6.1 μM and 8.2, 5.2, 6.1, 9.4 μM, respectively.In conclusion, 29 compounds were isolated from the endophytic fungi A606 and A616 from Pogostemon cablin, 5 of them were identified as new compounds, 8 compounds were proved to have significant bioactivty. This research provides a scientific theoretical basis for the development of the endophytic fungus.