the following embodiments further illustrate the present invention , rather than limiting the present invention . 1 . seed culture medium ( as well as fermentation culture medium ): each liter of culture medium comprised ( by weight ) 15 g of soluble starch , 5 g of soybean meal , 15 g of peptone , 15 g of glycerin , 2 g of caco 3 , 30 g of marine salt and the balance of water , and the ph was 7 . 4 . the above components were uniformly mixed , and sterilized for 30 min at 121 ° c . for later use . 2 . 1 seed culture : inoculating an activated streptomyces sp . scsio 10355 into 250 ml conical culture flasks , each flask containing 50 ml of the seed culture medium , culturing the inoculated seed culture medium at 28 ° c . and 200 rpm for 72 h to obtain a seed liquid . 2 . 2 . fermentation culture : inoculating the seed liquid into 20 l of fermentation medium according to an inoculation amount with a volume fraction of 10 %, and performing shaking culture of the inoculated fermentation culture medium at 28 ° c . and 180 rpm for 10 days to prepare a fermentation culture . 3 . extraction : separating a fermentation liquid fraction of the fermentation culture from a mycelia - containing fraction thereof by centrifugation ( 3500 rpm , 8 min ). extracting the fermentation liquid for four times with ethyl acetate , collecting ethyl acetate extract and performing decompressing distillation concentration to obtain an extract a ( 21 . 5 g ); leaching the mycelia with ethanol for three times , 15 min each time , collecting mycelia leaching solution , and performing decompressing to recover the ethanol from the mycelia leaching solution wherein an aqueous solution remains after said recovering of ethanol ; extracting the aqueous solution with ethyl acetate , performing decompressing distillation concentration of ethyl acetate extract to obtain an extract b ( 10 . 4 g ). mixing the extract a and the extract b to obtain a crude extract ( 31 . 9 g ). subjecting the crude extract ( 31 . 9 g ), prepared by mixing extra a and the extra b , to medium - pressure liquid chromatography over octadecylsilyl silica gel ( ymc - gel ods - a ), performing a gradient elution on the ods column containing said extract by eluting the silica gel column with water : methanol in a volume ratios that begins at 100 : 0 and ends at 0 : 100 ; collecting a 50 % methanol ( i . e ., the volume ratio of methanol : water is 1 : 1 ) fraction ( 0 . 7 g ); performing gel column chromatography ( over sephadex lh - 20 ) on the 50 % methanol fraction wherein the gel column chromatography is eluted with chloroform : methanol in a volume ratio of 1 : 1 to obtain a second fraction ; performing preparative thin - layer chromatography ( prep . tlc ) on the second fraction , wherein development is conducted for three times with chloroform - acetone ( volume ratio of 10 : 1 ) as a developing solvent , collecting compound having a rf value ( retention factor value ) of about 0 . 5 , and thereby strepsesquitriol ( 5 . 4 mg ) was obtained . structural identification : strepsesquitriol was obtained as a white amorphous powder , and its nmr data was as shown in table 1 ; the high resolution mass spectrum hresims thereof presented an adduct ion peak at m / z 277 . 1776 ([ m + na ]), which suggested the molecular formula c 15 h 26 o 3 , accounting for three degrees of unsaturation . the 1 h nmr spectrum exhibited one oxygenated methine at δ h 3 . 79 ( 1h , d , j = 6 . 3 hz , h - 2 ), and one doublet and three singlet methyls ( δ h 1 . 02 , 1 . 03 s , 1 . 09 s , and 1 . 48 s , each 3h , me - 4a , 9a , 9b , 10a ), wherein these signal peaks were supported by resonances in 13 c nmr spectrum at δ c 80 . 1 ( ch , c - 2 ), 14 . 6 ( ch 3 , c - 4a ), 23 . 3 ( ch 3 , c - 10α ), 21 . 8 ( ch 3 , c - 9b ), and 30 . 2 ( ch 3 , c - 9a ). all together , the 1 h , 13 c and dept nmr spectrum gave 15 signals including four quaternary carbons [ two were oxygenated : δ c 87 . 3 ( c - 5 ) and 85 . 0 ( c - 10 )], three methines , four methylenes and four methyls ( table 1 ). given that the 15 carbons are all sp 3 hybridized carbons , strepsesquitriol was concluded to bear three rings in its structure . in the 1 h — 1 h cosy spectrum thereof , we found two correlated long chains : h - 2 ( δ h 3 . 79 )/ h - 3β ( δ h 2 . 41 )/ h - 4 ( δ h 2 . 21 )/ h - 4a ( δ h 1 . 02 ) and h - 6β ( δ h 1 . 87 )/ h - 7β ( δ h 1 . 43 )/ h - 7α ( δ h 1 . 84 )/ h - 8 ( δ h 1 . 52 )/ h - 11β ( δ h 1 . 13 ), which allowed the assembly of two segments : c - 2 / c - 3 / c - 4 / c - 4a and c - 6 / c - 7 / c - 8 / c - 11 . these two fragments could be connected based on the key hmbc correlations originated from four methyls , one oxymethine ( h - 2 ), and two methylenes ( h - 6 and h - 11 ), which constructed the planar structure as 4 , 9 , 9 , 10 - tetramethyl - 2 , 5 , 10 - trihydroxyltricyclo [ 6 . 2 . 1 . 0 1 , 5 ] undecane . for further confirmation on the structure , we dissolved strepsesquitriol a in dmso - d 6 , performed spectrum analysis a second time and found the correlations of 5 - oh ( δ h 5 . 61 s ) to c - 5 / c - 4 / c - 1 / c - 6 , 2 - oh ( δ h 4 . 11 , d , j = 9 . 9 hz ) to c - 2 / c - 1 , and 10 - oh ( δ h 5 . 43 s ) to c - 1 / c - 10 / c - 9 , which established the planar structure of strepsesquitriol ( fig1 ). the assignment of relative configuration of strepsesquitriol was achieved by analysis of noesy spectrum in the solvent dmso - d 6 . as shown in fig2 , h - 3β was correlated to h - 2 / h - 11β / h - 4 , h - 4 was correlated to h - 6β / h - 7β / h - 11β , and h - 11α was correlated to h - 2 / h - 9a / h - 10a , while h - 3α was correlated to 2 - oh / h - 4a , h - 4a was correlated to 5 - oh , 5 - oh was correlated to h - 60α / h - 9b , and h - 9b was correlated to h - 7α / h - 6α / 10 - oh , thereby indicating that h - 2 / h - 3β / h - 4 / h - 6β / h - 7β / h - 11 / h - 9a / h - 10a were cofacial , just opposite to 2 - oh / h - 3α / h - 4a / 5 - oh / h - 6α / h - 7α / h - 9b / 10 - oh . since h - 6α was correlated to h - 9b / 10 - oh , h - 11β was correlated to h - 7β , and h - 11α was correlated to h - 9a / h - 10a respectively , ring b was deduced to be in a chair configuration , while ring c was in an envelope configuration . in addition , h - 11β was correlated to h - 4 / h - 3β , so ring a was deduced to be in an envelope configuration as well . on the basis of the above evidence , strepsesquitriol was determined to be 4α , 9 , 9 , 10β - tetramethyl - 2α , 5α , 10α - trihydroxyltricyclo [ 6 . 2 . 1 . 0 1 , 5 ] undecane . quantum - chemical calculations were performed , and theoretical optical rotation values ( theoretical or ) of ( 1r , 2r , 4s , 5s , 8s , 10s )- and ( 1s , 2s , 4r , 5r , 8r , 10r )- 4 , 9 , 9 , 10 - tetramethyl - 2 , 5 , 10 - trihydroxyltricyclo [ 6 . 2 . 1 . 0 1 , 5 ] undecane were respectively + 28 . 5 and − 28 . 6 , and since the measured values (+ 21 . 0 ) was close to + 28 . 5 and just opposite to − 28 . 6 , the absolute configuration thereof was determined to be ( 1r , 2r , 4s , 5s , 8s , 10s )- 4 , 9 , 9 , 10 - tetramethyl - 2 , 5 , 10 - trihydroxyltricyclo [ 6 . 2 . 1 . 0 1 , 5 ] undecane . the structure of strepsesquitriol was proposed to be as shown in formula ( i ): as for determination of inhibitory activity of strepsesquitriol on the formation of lipopolysaccharide ( lps )- induced tnfα in raw264 . 7 macrophages , please refer to the references ( fan , s . y . ; zeng , h . w . ; pei , y . h . ; li . l . ; ye , j . ; pan , y . x . ; zhang , j . g . ; yuan , x . ; zhang , w . d . the anti - inflammatory activities of an extract and compounds isolated from platycladus orientalis ( linnaeus ) franco in vitro and ex vivo j ethnopharmacol 2012 , 141 , 647 - 652 ) enref 3 . the results were as shown in table 2 : at a concentration of 100 μm , strepsesquitriol showed a strong inhibitory activity with an inhibition rate of 35 . 4 %, while the positive control drug n - p - tosyl - 1 - phenylalanine chloromethyl ketone showed an inhibition rate of 60 . 6 % at a same dose . in addition , at a concentration of 100 μm , strepsesquitriol showed no cytotoxic activity , thereby suggesting that it can be used for the preparation of low - toxicity and highly effective anti - inflammatory drugs .