The Secondary Metabolites And Their Bioactivities From Seven Endophytes In Plants

The endophytic bacteria in plants can product many types of the secondary metabolitism with bioactivity. It is a major source of bioactivity compounds and important for the discovery of lead compounds in medicine.In this work, the secondary metabolites from seven endophytes isolated from different plants and their activitis were also investigated. The seven endophytes include of four Streptomycetes sp. YIM66142, YIM66047, YIM66262, YIM67032, one Trichoderma sp. YIM Jing-8, a Nigrospora sp. E121 and Aspergillus cristatus T2-10.11 compounds, including of 97 different compounds ?seven of them were new compounds?, were obtained and their structure were elucidated by spectroscopic methods. Some of the compounds were investigated on the antimicrobial activity, photo-antimicrobial activity, cytotoxic activity, inhibition of acetylcholine esterase, free radical scavenging activity and inhibition of seed germination. The main results as follows:Eighty compounds, including four new compounds, have been isolated from 4 strains of Strepomyces sp. YIM66142, YIM66047, YIM66262 and YIM67032 which were isolated from Dendrobium chrysotoxum, Abelmoschus sagittifolius, Rabdosia loxothyrsa and Anemone rivularis, respectively. These compounds include of herbicidins, nonactic acid derivitives, cyclic lipopetides, anthraquinones, isoflavones, cyclic peptides and nucleosides etc.. Medelamine C and herbicidin B shown good antibacteril activity against B. subtilis and E. coli with MICs at 32 ?g/mL; desotamide showed antibiotical activity against B. subtilis, E. coli and S. aureus with MICs at 64,64, 128 ?g/mL, respectively. Herbicidins shown inhibition of seed germination about cabbage, and it was the first time to be reported on the phytotoxic activity for 2'-O-demethylherbicidin F and 8'-epi-herbicidin F with the MICs at 12.5-50 ?g/mL. The photo-antibiotical activity of anthraquinones isolated from Strepomyces sp. YIM66262 and YIM66043 were investigated, the results showed that the anthraquinone derivitives had the stronger antibacterial activity under irradiation than dark condition. Among them, antibacterial activity of chrysophanol was enhanced by photo-induce, with MIC decreased from 512 ?g/mLto 32 ug/mL against S. aureus, MIC from 128 ?g/mL to 8 ?g/mL against E. coli; kwanzoquinone G has obvious antibacterial activity with MIC decreased from 512 ?g/mL to ?g/mL aganinst E. coli.Thirty eight compounds, including three new compounds, isolated from 3 strains fungus, Jing-8, E121 and T2-10. These fungi were isolated from the stem of Panax notoginseng, Hydrocharis dubia and Gastrodia elata, respectively. These compounds include of alternariols, anthraquinones, ceramides, sesquiterpenes etc.. Alternariol and 1-hydroxymethyl-alternariol monomethyl ether from fungal Jing-8 showed significant DPPH radical-scavenging activities with IC₅₀ at 12 ?g/mL.1-Hydroxymethyl-alternariol monomethyl ether, a-acetylorcinol and cerebroside C show inhibition of seed germination of cabbage with MICs< 3 ?g/mL. Questin from fungus T2-10 had the antibacterial activity to B. subtilis, S. aureus and E. coli with MICs at 128,64 and 64 ?g/mL, respectively.In the end, the secondary metabolites from rare actinomycetes including mainland and marine were summarized from 2005 upto now.