Studies On The Secondary Metabolites From Streptomyces Sp. W112, An Endophytic Actinomycetes Of Camptotheca Acuminata

The secondary metabolites of actinomycetes has become an important sour ce of drugs. Because of the special habitat, endophytic actinomycetes, makes th em differentiate with the soil actinomycetes in the ways of metabolism and fun ctions. Thus, endophytic actinomycetes can produce some new compounds with special biological activities and phamaceutical values. The active substances sho w antibacterial, antitumor and anti-inflammatory activities. These all have show n that endophytic actinomycetes research have outstanding contributions and sig nificances in the field of new drug development, agriculture and biology, etc.In this paper, the secondary metabolites of endophytic actinomycetes Strept omyces sp. W112 mutant strain were chemically studied. A total of 22 compou nds including 8 new ones were isolated by column chromatography on silica g el, RP-18, Sephadex LH-20 and HPLC. The structures were identified by the a pplication of spectroscopy technologies and X-ray. Parts of compounds were te sted for the inhibitions of Type III secretion system (Type three secretion syste m, T3SS).The div8 gene overexpressed mutant strain Streptomyces sp. W112div8OE was cultured in Waksman agar medium and Oatmeal agar medium respectively. 10 compounds were isolated and elucidated from the Waksman agar medium e xtract, including one indolecarboxylic acid (WG-1), two benzoic acid derivative s (WG-3, WG-4), one betaine analogue (WG-5), four ansamycin derivatives (W G-6, WG-12, WG-15, WG-17) and one sesquiterpene (WG-13). Among them, WG-12, WG-15 and WG-17 are all new compounds.13 compounds were isola ted and elucidated from Oatmeal agar medium extract, including one benzoic a cid derivative (N-1), six Divergolide A derivatives (YS-181, YS-182, YS-361, YS-342, D2-1, D2-2), three Divergolide C derivatives (YS-351, YS-352, YS-38) and three Divergolide D derivatives (B4, YS-22, YS-12). YS-342、D2-1、D2-2、YS-22 and YS-12 are all new compounds.The results in this paper showed that the secondary metabolites of endoph ytic actinomycetes is one of the important resources for looking for drug lead compounds. The modification of the biosynthesis gene cluster encoded for the secondary metabolites of actinomycetes has a great of significance.