
Studies on anti-fouling compounds from saltern-derived extreme halophilic fungus Fusarium incarnatum GXIMD00527
LiangLifen,LuChunju,Fu Chunqing,Huang Huaqing,Chen Chunxiao,Qi Mengfan,Luo Xiaowei, Gao Chenghai Liu Yonghong, and Xu Xinya (InstituteofMarineDrugs/Guangxi KeyLaboratoryofMarineDrugs,GuangxiUniversityofChineseMedicine,Nanming 530200)
Abstract Objective To study the secondary metabolites of an extreme halophilic fungus,Fusarium incarnatum GXIMDoo527,and their marine antifouling activities against Amphibalanus amphitrite.MethodsThe secondary metabolites were isolatedby silicagel column chromatographyand purified using high-performance liquid chromatography.Their chemical structures were elucidated bythe comparisons of nuclear magnetic resonance data with literature.Theanti-fouling activities and cytotoxicities ofallcompounds against barnacle larvae atachment were determined.ResultsEight compounds were isolated and identified as four tetramicacid alkaloids: decalintetracid A(1), decalintetracid B(2), equisetin(3), 5′ -epiequisetin(4),and four 14-membered resorcylic acid lactones: zearalenone(5), a -Zearalenol(6),5'-hydroxyzearalenol(7), 8'-hydroxyzearalenone(8). Compounds 1\~5and 8 exhibited potent inhibitory efectson barnacle larval attchment,and compounds 1,4and 7 showed moderate inhibitory activities on the human colon cancer celline SW480.Conclusion The secondary metabolites of the extreme halophile fungus F. incarnatum GXIMDoo527 were significantly resistant to barnacle attchment fouling. This study firstly reported on anti-fouling compounds from the extreme halophile fungi derived from the Beibu Gulf saltern, which provided a theoretical basis for the development of natural anti-fouling agents.
Key WordsMarine fungus;Fusarium incarnatum; Secondary metabolites; Anti-fouling;Extreme halophilic fungus
海洋生物污損包括微型生物污損(細菌、真菌、微藻等污損微生物附著)和大型生物污損(藤壺、草苔蟲、管蟲、大型藻類等污損生物附著),對全球生態和經濟造成重大影響。污損生物在船舶、浮標等海洋設施上附著,增加船舶燃料消耗,導致更高的二氧化碳排放和過多的維護成本,甚至威脅海上設施的安全[1-2]。目前最為常用的抗海洋生物污損的方法是化學防污法,使用化學物質防止或去除污損生物附著[3]。添加重金屬的防污涂料如三丁基錫(TBT)是歷史上使用最廣泛的化學防污劑,每年為船舶行業節省600億美元的燃料,并減少3.84億噸的二氧化碳排放[]。但TBT釋放的化學物質會對海洋生物造成嚴重危害,包括生殖毒性、神經毒性、免疫毒性以及肝毒性等[4-6],影響海洋生態環境和海洋動植物健康[7],已被多個國家禁止使用[8-9]。為減少傳統防污涂料對海洋環境的破壞,從來源于海洋生物、易生物降解的海洋天然產物中研發綠色、高效的新型抗污劑迫在眉睫。
根據對氯化鈉的耐受程度,嗜鹽微生物可分為輕度嗜鹽(含鹽量 1%~5% 、中度嗜鹽(含鹽量5%~20% 和極端嗜鹽(含鹽量 20%~30% [10]。鹽的脅迫作用造就嗜鹽真菌通常具有獨特的代謝機制,可產生具有結構新穎,活性豐富的化合物,是抗污損物質的潛在來源[11-12]。北部灣具有豐富的鹽田嗜鹽微生物資源。北海竹林鹽場是廣西最大的天然海水晶鹽生產基地,生產面積達700公頃。本研究組前期從北海竹林鹽場飽和鹽度(含鹽量 36% 環境中分離得到6科6屬12種可培養極端嗜鹽真菌,初步活性評價顯示多株極端嗜鹽真菌都具有抗菌活性,并獲得了結構新穎的活性化合物[1l-14]。菌株F.incarnatumGXIMD00527是從北海竹林鹽場極端高鹽環境下分離純化得到的一株嗜鹽真菌,其發酵產物對4種指示細菌即人類致病菌耐甲氧西林金黃色葡萄球菌(MRSA)和表皮葡萄球菌、水產養殖致病菌無乳鏈球菌和海豚鏈球菌均有較強的抑菌活性 (MIC90lt;3.125μg/ mL),但北部灣海域極端嗜鹽真菌的抗污損活性尚未見報導[1]。近期發現該菌株提取物在 10μg/mL 濃度時對藤壺幼蟲附著抑制率為 65.4% ,具有產生高效天然防污劑的潛力。為了闡明 F. incarnatum GXIMD00527發酵產物中的抗污損活性成分,采用海洋天然產物化學的方法和技術,以期為新型高效天然抗污劑的研發提供理論依據和活性化合物。
1材料和方法
1.1 試劑及儀器
馬鈴薯提取粉、葡萄糖、胰蛋白陳和酵母浸膏等(廣東環凱微公司),分析純乙醇、二氯甲烷等(上海泰坦公司),色譜純甲醇、乙腈(上海星可公司),正相硅膠、薄層硅膠板(青島海洋化工廠),C-18ODS硅膠( S-50μm , 12nm 、分析色譜柱(日本YMC公司),半制備色譜柱(蘇州納譜公司),氘代試劑(美國CIL公司)。
旋轉蒸發儀(N-1300V-WB型,日本EYELA),恒溫培養振蕩器(ZWYR-2102型,上海智城公司),高壓滅菌鍋(MLS-3781L-PC型,普和希公司),高效液相色譜儀(LC-2030C3D型,日本Shimadzu公司),核磁共振波譜儀(AVANCE600型,德國Bruker公司)。
1.2培養基
馬鈴薯葡萄糖培養基(PD):馬鈴薯提取粉 6.0g 葡萄糖 20.0g ,氯霉素 0.1g , 3% 鹽度人工海水1000mL , 121°C 滅菌 25min 。
馬鈴薯葡萄糖瓊脂培養基(PDA):馬鈴薯提取粉6.0g ,葡萄糖 20.0g ,氯霉素 0.1g ,瓊脂粉 15.0g 3% 鹽度人工海水 1000mL , 121°C 滅菌 25min 。
大米固體培養基(RM):每 1L 廣口三角瓶分裝大米 80g ,酵母浸膏 0.4g ,葡萄糖 0.4g , 3% 鹽度人工海水 120mL , 121°C 滅菌 25min 。
1.3菌株分離與發酵
菌株(圖1)GXIMD00527分離自廣西北海市竹林鹽場( 21°26′35\" , 109°26′35\" ,結合形態學觀察(圖2)與ITS序列比對結果,確定菌株為Fusariumincarnatum(GenBank數據庫登錄號:ON287016)。菌株保存于廣西中醫藥大學海洋藥物研究院菌種保藏中心。
菌株接種于PDA平板,置于 28°C 培養箱中恒溫培養3d。將活化后的菌株接種于PD培養基,震蕩( 28°C , $1 8 0 \mathrm { \ r / m i n } \$ 培養 3d ,得到種子液。將GXIMD00527種子液按 10% 接種量接種,轉接于大米培養基上,使用1L的三角錐形瓶,共發酵100瓶,28°C 靜置培養 40d 0

1.4提取與分離
發酵產物用等體積乙酸乙酯浸泡,超聲提取3次,得到菌株發酵提取物約 400g 。提取物使用正相硅膠(200\~300目, 2kg 柱色譜法, CH2Cl2/ MeOH(100:0\~80:20,V/V,下同)系統梯度洗脫,得到10個流分(Fr.1\~Fr.10)。Fr.5經ODS反相中壓柱色譜梯度分離后經半制備HPLC純化 (MeOH/H2O ,52:48)得到化合物5 (8.5mg) )。Fr.6經ODS反相中壓柱色譜梯度 (ACN/H2O , 10:0~80:20) 洗脫得到18個亞流分(sFr.6-1\~sFr.6-18)。sFr.6-9經半制備HPLC純化(ACN/H2O ,32:68)得到化合物8 (4.5mg) 。sFr.6-10經半制備HPLC純化
,32:68)得到化合物 6(4.2mg) 。sFr.6-13半制備HPLC純化(
,38:62)得到化合物1( 18.5mg )。Fr.8經ODS反相中壓柱色譜梯度洗脫后經半制備HPLC柱等度 (ACN/H2O ,35:65)純化得到化合物2 (29.4mg) 。Fr.9經ODS反相中壓柱色譜梯度洗脫后HPLC純化 (ACN/H2O ,22:78)得到化合物7 (12.0mg) 。Fr.10經ODS反相中壓柱色譜梯度(ACN/H2O ,10:0\~80:20)洗脫得到17個亞流分(sFr.10-1\~sFr.10-17)。sFr.10-16液相純化
,42:58)得到化合物3 10.6mg) 和4 (20.8mg) 。

1.5 活性測定
1.5.1 抗污損活性測定
實驗所需的藤壺成體采集廣西防城港,經廣西中醫藥大學海洋藥物研究院劉昕明博士鑒定為紋藤壺(Amphibalanusamphitrite)。藤壺成體于陳化海水(鹽度: 2.8% 中培養,收集藤壺幼蟲。將藤壺幼蟲置于海水(鹽度: 2.8% 中培養,4d后部分IV期無節幼蟲變態為金星幼蟲,以三角褐指藻(PhaeodactylumtricornutumBohlin)作為餌料。培養4\~5d后藤壺幼體從無節幼體變態為金星幼體,收集金星幼體。實驗設置空白組,樣品組及溶劑對照組,樣品設置終濃度梯度為25、10、5和 1μmol/L 。等體積海水為空白對照組,等體積DMSO為溶劑對照組,終濃度15和
4,5-dichloro-2-octyl-isothiazolone(DCOIT)為陽性對照組。設置3個平行,放置黑暗恒溫室內 48h 觀察每孔中金星幼蟲附著變態情況,計算金星幼蟲附著率。
1.5.2 腫瘤細胞毒活性測定
使用MTT染色法測定單體化合物的對人結腸癌細胞系SW480細胞毒活性。具體步驟如下:細胞在L15培養基上培養(
, 5%CO2) ,待測試的所有細胞的傳代數為 3~6 。單體化合物使用DMSO溶解,加入樣品后于 37° 孵育 24h 。培養結束后每孔加入使用PBS溶解的MTT溶液( 20μL , 5mg/mL 孵育 4h ,吸去培養液上清,加入 100μL DMSO溶解結晶。充分溶解后,酶標儀測定A490°
2 結果與分析
2.1化合物結構鑒定(圖3)
化合物1:無色固體,液相色譜分析顯示為一 對可互變的色譜峰。核磁數據顯示兩套信號峰,積 分比例約為1.2:1。1a: 1H NMR( 600MHz DMSO ?d6 δH: 5.82 (1H, m,H-5),5.65 (1H, m,H-14),5.15 (1H, m, H-13),4.79 (1H,m,H-4), 3.67 (1H, m,H-6), 3.66 (1H, m,H-5'),2.85(3H,s,H-7),2.75(1H,dd, J=9.5 ,3.2 Hz,H-3),2.30(1H,m,H-11),2.12 (1H,m,H-7a),1.93 (1H,m,H-10a),1.81(1H,m,H-9a),1.64(3H,d,J=6.3 Hz,H-15),1.50(1H,m,H-7b),1.50(1H,m,H-8),1.6 (1H,m,H-1b),1.33(3H,s,H-12),1.09(1,m,H-9b), 0.88 (3H,d,J=6.3 Hz,H-16). 13 C NMR(150 MHz, DMSO- ?d6) δc :194.54 (C-4'),185.0 (C-1),166.3 (C-2'), 145.9 (C-6), 128.8 (C-14), 127.6 (C-13), 119.5 (C-5),

103.4(C-3),82.7 (C-4),66.8(C-5D), 57.7 (C-6),54.0 (C-2), 51.1 (C-3), 43.6 (C-11), 42.6 (C-7), 34.5 (C-8), 34.0 (C-9),27.7 (C-10),26.5 (C-7'), 22.0 (C-16), 17.8 (C-15),16.6 (C-12). 1b: 1H NMR (600 MHz, DMSO- ?d6) δH. 5.82(1H,m,H-5),5.65(1H,m,H-14),5.15(1H, m,H-13),4.79 (1H,m,H-4),3.67 (1H,m,H-6),3.58 (1H,m,H-5), 2.82 (3H, s,H-7),2.75 (1H, dd, J=9.5 3.2 Hz, H-3), 2.50 (1H,overlapped,H-11), 2.12 (1H, m, H-7a),1.93(1H,m,H-10a),1.81(1H,m,H-9a),1.64 (1H, m,H-15),1.50 (1H,m,H-7b),1.50 (1H,m,H-8), 1.41 (3H, s,H-12),1.36 (1H,m,H-10b),1.09 (1H, m, H-9b),0.88(3H,d, J=6.0Hz ,H-16). 13C NMR(150 MHz, DMSO- ?d6 ) δc :194.1 (C-4),183.6 (C-1),167.0 (C-2'), 146.2 (C-6), 128.8 (C-14), 127.6 (C-13), 119.5 (C-5), 103.8 (C-3), 82.7 (C-4), 67.7 (C-5'), 58.4 (C-6), 53.5 (C-2), 51.1 (C-3), 44.8 (C-11), 42.6 (C-7), 34.5 (C8), 34.0 (C-9), 27.6 (C-10), 27.1 (C-7), 22.0 (C-16), 17.8 (C-15),17.5(C-12)。經文獻比對[15],波譜數據與 decalintetracidA基本一致,結構如圖3所示。
化合物2:無色固體,液相色譜分析顯示為一對 可互變的色譜峰。核磁數據顯示兩套信號峰,積分 比例約為1.3:1。2a: 1H NMR (600MHz DMSO- ?dω6)
(1H, ddd, J=10.0 ,4.9, 2.5Hz ,H-4), 5.57 (1H, d, J=10.4Hz ,H-5), 4.14 (1H, dd, J=10.1 , 6.6 Hz, H-13), 3.70 (1H,m,H-5'), 3.70 (1H, m,H-6'a),3.64 (1H, m, H-6'b), 3.57 (1H,m,H-14),2.82 (3H, s,H-7),2.45 (1, dd, J=10.1 ,4.6 Hz,H-3),1.90 (1H,m,H-6),1.81(1H, m,H-7a),1.64(1H,m,H-9a),1.46(1H,m,H-8),1.42 (2H,m,H-10),1.40(3H,s,H-12),1.35(1H,m,H-11), 1.22(3H,dd,J=14.1,6.3Hz,H-15),0.86(1H,m,H-9b), 0.86 (3H,d, J=6.3 Hz,H-16),0.72 (1H,m,H-7b). 13C NMR(150MHz,DMSO- dc )δ:194.6 (C-4),183.6 (C1), 166.6 (C-2'),133.1 (C-5), 122.4 (C-4),104.1 (-3), 91.7 (C-13), 68.3 (C-5), 66.6 (C-14), 58.1 (C-6), 52.7 (C-2), 49.7 (C-3), 43.0 (C-11), 41.0 (C-7), 36.5 (C-6), 35.1 (C-9), 32.1 (C-8), 26.6(C-7'), 26.4 (C-10), 22.4 (C16), 20.0 (C-15), 15.0 (C-12). 2b: 1H NMR ( 600MHz. DMSO- ?d6 ) δH. 5.65(1H,ddd, J=10.0 ,4.9,2.5Hz,H-4),
5.57(1H,d,J=10.4Hz,H-5),4.10 (1H,dd, J=10.1 6.6Hz,H-13),3.74 (1H,m,H-5'),3.70 (1H,m,H-6'a), 3.64 (1H,m,H-6'b),3.58 (1H, m, H-14), 2.85 (3H, s, H-7'), 2.45 (1H, dd, J=10.1 , 4.6 Hz, H-3), 1.90 (1H, m, H-6),1.81(1H,m,H-7a),1.64(1H,m,H-9a),1.48(3H s,H-12),1.46 (1H,m,H-8),1.48 (2H,m,H-10),1.35 (1H,m,H-11),1.24 (3H,d,J=6.4 Hz,H-15),0.86 (3H, d,J=6.5 Hz,H-16), 0.80 (1H,m,H-9b),0.72 (1H, m, H-7b).1’CNMR(150 MHz,DMSO ?d ) δc : 193.8 (C-4'), 182.3 (C-1),166.6(C-2'), 132.9 (C-5),122.6(C-4),104.50 (C-3'), 91.4 (C-13), 68.5 (C-5'), 66.9 (C-14), 58.3 (C-6), 52.1 (C-2), 50.3 (C-3), 42.3 (C-11), 41.1 (C-7), 36.5 (C-6), 35.0 (C-9),32.1 (C-8),27.0 (C-10),26.9 (C-7),22.4 (C16),20.4(C-15),15.9(C-12)。經文獻比對[15],波譜數 據與decalintetracidB基本一致。
化合物3:無色固體。 1H NMR( 600MHz DMSO- ?d6 )
5.34-5.42 (2H, overlapped, H-4,H-5), 5.24 (1H, qd, J=12.6 , 6.2Hz ,H-13),5.08 (1H, m, H-14),3.81 (1H,d, J=11.0Hz ,H-6'a),3.75(1H, overlapped,H-5'),3.72(1H, d, J=11.0Hz ,H-6'b),3.32 (1H,overlapped,H-3),2.94(3H, s,H-7),1.92 (1H,br s,H-10a),1.79-1.84 (2H, m,H-6, H-7a), 1.71 (1H, br s, H-9a),1.58 (1H,m,H-11),1.49(1H,m,H-8),1.45 (3H, d, J=6.0Hz ,H-15),1.41 (3H, s,H-12),1.02 (2H, m, H-9b,H-10b),0.89 (3H, d,J=6.3Hz,H-16),0.83(1H, d, J=12.2Hz ,H-7b). 13C NMR(150 MHz, DMSO- d6 ) δc :195.8 (C-4'), 190.2 (C-1), 176.1 (C-2), 130.5 (C-14), 129.8 (C-5), 127.2 (C-13),126.5 (C-4),100.6 (C-3'), 67.5 (C-5'), 57.7 (C-6), 48.0 (C-2), 44.1 (C-3), 41.8 (C-7), 40.0 (C-11), 38.2 (C-6),35.4 (C-9), 32.9 (C-8),27.8 (C10),26.8 (C-7'),22.4 (C-16),17.7 (C-15),13.9 (C-12)。經 文獻比對[16],波譜數據與equisetin基本一致。
化合物4:無色膠質。 1H NMR( 600MHz , DMSO- ?d6? ) δH :5.30\~5.40 (2H,overlapped,H-4,H-5), 5.08-5.20 (2H, overlapped,H-13,H-14), 3.80 (1H, d, J=11.6Hz ,H-6'a),3.74(1H,overlapped,H-5'),3.68 (1H, d, J=11.9Hz ,H-6'b),3.33(1H,overlapped,H-3), 2.94 (3H,s,H-7'),1.90(1H,br s,H-10a),1.76\~1.82 (2H, m,H-6,H-7a),1.70 (1H,brs,H-9a),1.58 (1H, m, H-11),1.48 (1H,overlapped,H-8),1.49 (3H, d, J=4.7 Hz, H-15),1.36 (3H, d, J=6.0Hz ,H-15),1.01 (2H,m, H-9b,H-10b),0.88 (3H,d, J=6.3Hz ,H-16),0.81 (1H, m, H-7b). 13C NMR ( 150MHz DMSO-d6) δc: 201.4 (C4'),190.7 (C-1), 176.4 (C-2'),131.07 (C-13),131.0 (C5), 129.9 (C-4), 126.5 (C-14), 100.9 (C-3'), 67.6 (C-5'), 58.1 (C-6), 48.6 (C-2), 47. 9 (C-3), 44.4 (C-7), 41.8 (C11),38.2 (C-6), 35.4 (C-9), 32.9 (C-8), 29.0 (C-10), 27.7 (C-7),22.4 (C-16),17.8(C-15),13.8(C-12)。波數 據與化合物3相近,主要區別在C-4'和C-6'的核磁數 據。經文獻比對[16],確定化合物4為5'-epiequisetin。
化合物5:白色固體。 1H NMR( 600MHz , DMSO- ?d6 )
6.60 (1H, m, H-12), 6.37 (1H, d, J=2.3 Hz, H-13),6.23 (1H, d, J=2.3Hz ,H-15),5.79(1H,dt, J=15.0 , 7.2Hz ,H-11),4.99 (1H,m,H-3),2.47 (1H, dd, J=9.0 ,3.2Hz,H-8a),2.44-2.31 (2H,overlapped,H-6a, H-10a),2.23-2.06(3H,m,H-6b,H-8b,H-10b),1.74(1H, m,H-9a),1.69-1.62 (2H,m,H-5),1.62-1.55 (2H, m, H-4),1.49(1H,m,H-9b),1.28 (3H,d, J=6.2Hz H-2). 13C NMR(150 MHz, DMSO- d6 δc 210.6 (C-7), 169.5 (C-1),161.1 (C-16),160.8 (C-14),140.1 (C-18),132.0 (C-12), 130.9 (C-11),106.7 (C-13),105.9 (C-17), 101.6 (C-15), 71.9 (C-3), 42.9 (C-6), 36.3 (C-8), 34.3 (C-4), 30.8 (C-10),21.3 (C-5),20.8 (C-9),20.1 (C-2)。經文獻 比對[17],波譜數據與zearalenone基本一致。
化合物6:白色固體。 1H NMR ( 500MHz 0 DMSO- ?d6? ) δH :9.83(2H,br s,OH-14,OH-16),6.39 (1H, d, J=2.1Hz ,H-13),6.28(1H,d, J=15.7Hz ,H-12), 6.20 (1H, d, J=2.1Hz H-15),5.98 (1H,m,H-11),5.11 (1H,m,H-3), 4.32 (1H,br s,OH-7),3.47 (1H,m,H-7), 2.18 (2H,m, H-10),1.74 (1H, m, H-6a),1.64(1H, m, H-9a),1.33\~1.55(5H,overlapped,H-4a,H-5a,H-6b, H-8a,H-9b),1.27 (1H,m,H-8b),1.20 (3H, d, J=6.4 Hz,H-2),1.10 (2H, m, H-4b, 5b). 13C NMR (125MHz, DMSO- ?d6? ) δc :168.2 (C-1), 159.3 (C-16), 156.7 (C-14), 137.1 (C-18), 132.2 (C-12), 128.1 (C-11), 111.9 (C-17), 103.0 (C-13),101.3 (C-15), 70.5 (C-3), 66.7 (C-7), 36.4 (C-8), 34.2 (C-6), 31.9 (C-4), 30.1 (C-10), 22.3 (C-9), 19.0(C-2),18.8 (C-5)。經文獻比對[18],波譜數據與 α-zearalenol基本一致。
化合物7:白色固體。 1H NMR (500MHz , DMSO- ?d6) δH 6.40 (1H, d, J=1.7Hz ,H-13), 6.26 (1H, dt, J=16.2 5.0Hz ,H-11), 6.20 (1H, d, J=1.8Hz ,H-15), 6.12 (1H, d, J=16.3Hz ,H-12),4.99 (1H,ddt, J=12.1 0 8.6,4.2Hz,H-3),4.29(2H,br s,OH-7,OH-8),3.53(1H, d, J=9.0Hz. ,H-7),3.39 (1H,d, J=8.9 Hz,H-8),2.34 (1H, m,H-10a),2.23(1H,m,H-10b),1.65(2H,overlapped, H-4a,H-9a),1.56(1H,m,H-4a),1.53-1.40 (2H,m, H-6a,H-9b),1.33 (1H, m, H-6b),1.31-1.25 (2H, m, H-5),1.24 (3H, d, J=6.1 Hz,H-2). 13C NMR(125MHz, DMSO-
) δc :168.5 (C-1), 158.8 (C-16),155.8 (C14), 135.9 (C-18), 131.8 (C-12), 125.1 (C-11), 113.2 (C13), 102.1 (C-17), 101.2 (C-15), 75.2 (C-7), 69.1 (C-8), 69.1 (C-3), 34.8 (C-4), 32.4 (C-6), 25.8 (C-10), 25.6 (C9),20.4(C-5),20.4(C-2)。經文獻比對[19],波譜數據與 5'-hydroxyzearalenol基本一致。
化合物8:白色固體。 1H NMR (500MHz DMSO- ?dω6) (2
6.76 (1H, d, J=15.3Hz ,H-12), 6.36 (1H, d, J=2.3Hz H-13),6.22(1H,d, J=2.3Hz ,H-15), 5.71 (1H, ddd, J=14.8 ,9.1, 5.1Hz ,H-11),5.17(1H,ddd, J=11.3 ,6.2,1.8Hz,H-3),4.94(1H,br s,OH-5),3.92 (1H, q, J=8.1Hz ,H-5),2.66 (1H, dd, J=11.2 , 5.1Hz, H-6a),2.48(2H,overlapped,H-6b,H-8a),2.40(1H, dd, J=6.6 ,2.6Hz,H-8b),2.18(1H,dd, J=11.2 ,8.9Hz, H-10a),2.05(1H,m,H-10b),1.82(1H,m,H-9a),1.65 (1H,m,H-4a),1.56 (1H,m,H-9b),1.49(1H,m,H-4b), 1.31 (3H, d, J=6.2Hz ,H-2). 13C NMR( 125MHz DMSO- ?d6) δc :208.3 (C-7), 170.0 (C-1), 162.6 (C-16), 161.9 (C-14), 141.5 (C-18), 131.9 (C-12), 131.9 (C-11), 107.1 (C-13), 104.5 (C-17), 101.7 (C-15), 69.2 (C-3), 63.5 (C-5), 53.3 (C-6), 42.8 (C-4), 37.4 (C-8), 30.6 (C10),20.8(C-9),20.4(C-2)。經文獻比對[18],波譜數據 與8'-hydroxyzearalenone基本一致。
2.2化合物活性結果
2.2.1 抗污損活性
如圖4所示,在不同濃度(1、5、10和 25μmol/L 時,化合物1\~5和8對紋藤壺金星幼蟲附著均有較強的抑制活性,強于陽性對照DCOIT(濃度15和 60μmol/L) 。
2.2.2 細胞毒活性
設置各藥物終濃度為
,化合物1\~8對SW480細胞的抑制率對比陽性藥物Cisplatin(CDDP)
如圖5所示,其中化合物1、4和7對該細胞抑制率分別為 58.83% 一 63.83% 和 61.20% 。
3討論
從1株鹽場來源極端嗜鹽真菌變紅鐮刀菌F.incarnatumGXIMD00527中分離鑒定了8個化合物,包括4個特特拉姆酸類生物堿(1\~4)和4個十四元二羥基苯甲酸內酯類化合物(5\~8),部分化合物顯示出顯著的抗海洋生物污損活性和細胞毒性。特特拉姆酸類生物堿骨架為吡咯烷-2,4-二酮結構,具有廣泛的生物活性[20]。Zhao等[15]發現decalintetr acid A(1)、decalintetracidB(2)存在一定的植物毒性。Vesonder等[21]的研究發現equisetin(3)對革蘭陽性菌:枯草芽胞桿菌(Bacillussubtilis)、草分岐桿菌(Mycobacteriumphlei)、金黃色葡萄球菌(Staphylococcusaureus)均具有較強抑制活性。十四元二羥基苯甲酸內酯以連接在間苯二酚芳香環上的大環內酯為核心結構,該類化合物在結構上的多樣性由于氧化程度及不飽和程度的位置及數量不同而形成[22]。根據文獻報道,化合物zearalenone(5)對新型隱球菌(Cryptococcusneoformans)、金黃色葡萄球菌(Staphylococcusaureus)微弱的抑制作用,MIC分別為50和 400μmol/L[23] ,并對植物病原真菌稻瘟菌(Pyriculariaoryzae)有明顯的抑制作用,MIC為 6.25μg/mL[24] 。但是目前暫未發現上述化合物的抗污損活性報道。其抗污損活性的作用機制有待進一步研究。化合物1和6還對腫瘤細胞株SW480顯示出一定的抑制作用。


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