Chemical Components And Bioactivities Of Ethanolic Extracts From Agarwood Of Aquilaria Filaria (Oken) Merr.

Agarwood,a product from wounded tree of the Aquilaria and Gyrinops species,shows high diversity in their pharmacological effects,such as anti-inflammatory,neuroprotective,cytotoxicity,and acetylcholinesterase inhibitory activities,and so on.In practice,only the heartwood of Aquilaria malaccensis,A.crassna,A.sinensis and A.filaria are commercially exploited.Sesquiterpenoids and 2-(2-phenylethyl)chromone derivatives were mainly reported from agarwood of Aquilaria sinensis,A.malaccensis and A.crassna,however,chemical constituents of agarwood of A.filaria were rarely investigated.As the continuing efforts to carry on systematic and comprehensive study of agarwood,and to explore the difference in main chemical composition between agarwood of A.filaria and other species,we have focused on the phytochemical investigation and bioactivity evaluation on agarwood of A.filaria which was collected in Indonesia.By using various chromatographic techniques,including silica gel,sephadex LH-20,ODS column chromatography and prepared HPLC,90 compounds(1-90)were isolated from agarwood of A.filaria,their structures were identified by spectral methods(NMR,HRESIMS,IR,UV)and compared with published data,1-28 were new compounds that were named as(4R)-3-oxo-gweicurculactone(1),(4R,5S)-3-oxo-5,6-dihydro-gweicurculactone(2),1(5)-ene-7,10-epoxy-guaia-12-one(3),1,8-epoxy-5H-guaia-9-en-12,8-olide(4),15-hydroxy-guaianolide(5),4?,5?,7?,8?,11?-H-10?-hydroxy-guai-1(2)-en-12,8-olide(6),4?,5?,7?,8?,11?-H-10?-hydroxy-guaia-1(2)-en-12,8-olide(7),4?,5?,8?,11?-H-7?,10?-dihydroxy-guaia-1(2)-en-12,8-olide(8),4?,5?,8?,11?-H-7?,10?-dihydroxy-guaia-1(2)-en-12,8-olide(9),4?,7?-H-11,13-dihydroxyeremophil-1(2),9(10)-dien-11-methy ester(10),11-(2,2-dimethyl-1,3-dioxane-5-yl)-4?,7?-H-eremophil-9(10)-ene-11-ol(11),4?,7?,8?-H-eremophil-9(10)-ene-8,12-epoxy-11?-ol(12),4?,5?-H-12?-hydroxy-daphnauranolC(13),(R)-6-hydroxy-2-(1-hydroxy-2-phenylethyl)chromone(14),(S)-6-hydroxy-2-(1-hydroxy-2-phenylethyl)chromone(15),6-hydroxy-8-methylsulfinyl-2-(2-phenylethyl)chromone(16),5,8-dihydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone(17),5,8-dihydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone(18),6,7-dihydroxy-2-[2-(3-hydroxyphenyl)ethyl]chromone(19),6,7-dihydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone(20),6,7-dihydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone(21),6,7-dihydroxy-2-[2-(3-hydroxy-4-methoxyphenyl)ethyl]chromone(22),6,7-dihydroxy-2-[2-(4-hydroxy-3-methoxyphenyl)ethyl]chromone(23),6-hydroxy-2-[2-(3-hydroxyphenyl)ethyl]chromone(24),8-hydroxy-2-[2-(4-methoxyphenyl)ethyl]chromone(25),5-hydroxy-2-[2-(3-hydroxy-4-methoxyphenyl)ethenyl]chromone(26),(5R,6R,7R,8R)-8-chloro-5,6,7-trihydroxy-2-(3-hydroxy-4-methoxyphenethyl)-5,6,7,8-tetra hydrochromone(27),and(6S,7S,8S)-6,7,8-trihydroxyl-2-(2-phenylethyl)-5,6,7,8-tetrachromone(28).Structurally,compounds 1-13 and 29-34 were sesquiterpenes,14-28and 35-63 were 2-(2-phenylethyl)chromone derivatives,64-90 were compounds of other types.Among them,1-28 were new compounds that weren't reported elsewhere,compounds 1-38,41,43-45,47-49,and 51-90 were firstly reported from agarwood of A.filaria.A part of the isolated compounds were tested for their?-glucosidase inhibitory activity,anti-inflammatory,and cytotoxicity.Compounds 16-25,29,and 35-50 exhibited different level of inhibition of?-glucosidase with IC₅₀ values ranging between 7.8±0.3and 253.2±9.7?M(acarbose,743.4±3.3?M).In the kinetic studies,compounds 17,20–22,24,35,37,39-43,and 45-47 were found to be mixed type inhibitors for?-glucosidase and the sesquiterpene 29 was a competitive inhibitor,molecular docking simulations revealed the binding sites and interactions of 29 with?-glucosidase,compound29 formed hydrogen bond with residue Arg442 of?-glucosidase;Compounds 17,18,36,40,42,46,and 47 exhibited weak inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells with inhibition ratio more than 50%at the concentration of 100?M(Indometacin:78.5±2.1%,50?M);compounds 2–4 displayed weak cytotoxicity against K562 tumor cell lines with IC₅₀ values at 45.1±1.2,48.6±0.7,and 33.8±1.5?M,respectively(Doxorubicin:0.07±0.01?M).Above all,this paper reported the isolation and identification of 90 compounds including 28 new compounds from agarwood of A.filaria,which provided chemical basis for the identification of agarwood of A.filaria,expanded the agarwood of chemical database,as well as provided foundation for the development of agarwood originated from A.filaria.