| In order to take advantage of resources of medical plants and endophytic actinomycetes,especially to discover natural products with anti-HIV activity and novel structure from medical plants,and to find environmentally friendly biopesticide precursors from endophytic actinomycetes,the system chemical composition research and the biological activity screening of three medical plants and eight endophytic actinomycetes were carried out in this paper,including Euphorbia royleana,Euphorbia antiquorum,Swertia bimaculata and eight endophytic actinomycetes from poisonous plants of family Ericaceae.By means of various chromatography,NMR,MS and X-Ray diffraction experiments,in combination with calculated ECD method,144 compounds were isolated and identified from the above medical plants and endophytic actinomycetes,the structure types involved diterpenoids,sesterterpenoid,triterpenes,xanthones,lignans,macrocyclic peptides,macrolides,and so on.Among them,24 compounds were new and 1 compound was new natural product.In addition,we took bioactivity screening researches of the isolated compounds,including anti-HIV activity,inhibitory nitric oxide production activity,reversing multidrug resistance activity,cytotoxic activity,and antimicrobial activity,and some compounds with good activities were obtained.Results indicated that some of these isolates exhibited moderate biological activities which have important significance for scientific understanding of the pharmacological activitives of Euphorbia royleana,Euphorbia antiquorum and Swertia bimaculata and the biocontrol potential of endophytic actinomycetes.The fresh stem of Euphorbia royleana is usually used as a pesticide in Chinese folk,and the mashed fresh stem can be used as a treatment of psoriasis.50 compounds,including 17 new ones,were isolated and identified from the EtOAc extract of E.royleana.Among them,compounds 1-14 were new diterpenoids.New compounds were named as euphorcembrane(1),euphoroynoid A(2),euphoroynoid B(3),euphoroynoid C(4),euphoroynoid D(5),euphoroynoid E(6),euphoroynoid F(7),euphoroynoid G(8),euphoroynoid H(9),euphoroynoid I(10),euphoroynoid J(11),euphoroynoid K(12),euphoroynoid L(13),euphoroynoid M(14),octadecenoic ester A(15),octadecenoic ester B(16)and butanedioester(17).Compound 1 is a cembrane diterpenoid which was firstly discovered from Euphorbia.This support the source approach hypothesis that cembrane diterpenoid is the precursor of other macrocyclic diterpenoids.Furthermore,compound 10 had significant inhibitory effects on NO production in a murine macrophage RAW 264.7 cells,with IC50 values of 16.4?M.Compounds 19 and 22 exhibited weak activities of reversing multidrug resistance in HepG2/ADR(RF = 12.5?14.9).The triterpenoids contained fraction D suppressed NO production of LPS-stimulated RAW264.7 macrophages,with an IC50 of 6.9?M,which indicated that triterpenoids may play a major role in anti-inflammatory effect of E.royleana.Euphorbia antiquorum has long been used as an herbal medicine in China for the treatment of cutaneous infections and toothache,its latex used for vomiting.Our investigation of the acetone extract of the stems led to the isolation of 28 compounds,including three new ones named 25,26,27-trinor-3a-hydroxy-24-dimethoxyeuphane(1),euphane-24?-hydroperoxy-8,25-diene-3?-ol(2)and ent-atisane-3?,16?,17-triol(3).Compound 1 was a 25,26,27-trinor euphane type triterpene found in Euphorbia for the first time.Furthermore,compound 8 showed moderate activity in inhibiting HIV-1 replication by 50%(EC50)at 1.38?M.Compounds 8,9 and 11 exhibited weak activities of reversing multidrug resistance in HepG2/ADR(RF = 18.0?31.0).The traditional medical plant Swertia bimaculata has been used for the treatment of dyspepsia,urinary infection,and hepatitis diseases in middle-west of China.From its EtO Ac-soluble fraction thirty compounds were isolated,three of which were new ones and named aspterpenacid C(1),(-)-swerimusaldehyde A(2)and 3,3',5-trihydroxybiphenyl-2-ethanone(3).Among them,compound 1 was a new sesterterpenoid with an unusual 5/3/7/6/5 pentacyclic skeleton,which separated from plant for the first time.In activities tests,Compound 1 exhibited moderate activity in HIV-1 replication by 50%(EC50)at 1.35?M and inhibiting NO production(IC50 = 16.1?M).Compound 16 showed good inhibition of NO production in vitro(ICs50 9.7 ?M).Research on three poisonous plants,Rhododendron decorum,Rhododendron molle and Pieris japonica(family Ericaceae),got 55 endophytic actinomycetes and eight of them were selected to fermentation based on the antibiotic activities screening.A total of 36 compounds were isolated from these fermented liquids,including a new compound named actinomycin Z6(1)and one new natural product named 4-[2'-(3"(R),5"(S)-3",5"-dimethyl-2"-oxocyclohexylidene)ethyl]piperidine-2,6-dione(17).Compound 1 was the first example of the Z-type actinomycins with an additional ring bridged by C-O-C-ether bonds between the 4-OH of HThr and C-2 of the chromophore.Compounds 17 and 14 have broad spectrum antifungal activities for exhibited obvious inhibitory activities against seven and six common fungi of crops,respectively.Indicating that these compounds have the potential to become biological pesticides,and have a certain significance for protecting environment. |
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