BÁO CÁO KHOA HỌC: Xerocomus langbianensis

Chrysospermins A, B, C, D được chiết xuất như là những peptaibols ở quả thể của nấm Xerocomus langbianensis và cấu trúc của chúng đã được xác định bởi Mass spectrometrie. Những chrysospermin này đã được phát hiện trước đây trong khi nghiên cứu sinh khối của nấm sợi Sepedonium chrysospermum (telemorph Apiocrea chrysosperma).
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BÁO CÁO KHOA HỌC: "Xerocomus langbianensis"Xerocomus langbianensis.Trịnh Tam KiệtTrung tâm Công nghệ Sinh học, Đại học Quốc gia Hà NộiUdo Graefer, Peter Saluz, B. SchelegelViện nghiên cứu Hoá các hợp chất tự nhiên Jena,CHLBĐức.Chrysospermins A, B, C, D được chiết xuất như là nhữngpeptaibols ở quả thể của nấm Xerocomus langbianensis vàcấu trúc của chúng đã được xác định bởi Massspectrometrie. Những chrysospermin này đã được phát hiệntrước đây trong khi nghiên cứu sinh khối của nấm sợiSepedonium chrysospermum (telemorph Apiocreachrysosperma). Những kết quả này có thể liên quan tới việcXerocomus langbianensis đã bị tấn công bởi các đại diệncủa nấm sinh đính bào tử. I. AbstractChrysospermins A- D were isolated recurrently as 19-membered peptaibols in a fruiting body of Xerocomuslangbianensis and structure was confirmed by ESI massspectrometry. The chrysospermins A – D3) were detectedformerly in cultures of Sepedonium chrysospermum(telemorph Apiocrea chrysosperma).The result suggestedthat the old Xerocomus langbianenis was infected by arepresentative of the conidial fungi.II. IntroductionPeptaibols such as aibelin, alamethicins, atiamoebins,emerimicins, paracelsin, saturnisopin, suzukacillin,trichorzianins, trikoningins, zervamicins (3) are ofconsidarable biological interest products because theyfaciliate the transport of ions across membranes viamechanism involving pore formation. The fungusSepedonium chrysospermum (telemorph Apiocreachrysosperma) was found to produce novel antifulgalpeptides, chrysospermins A (1), B (2), C (3), D (4) asmember of the peptaibol class of linear lipophilic peptideantibiotics (3). Therefore chrysospermins promote pigmentformation by surface culture of the mold fungus Phomadestructiva. The fungus Sepedonium ampullosporumknown as the producer of the similar peptaibolsampullosporins A- E1,2) . The another filamentous fungisuch as Trichoderma herxianum, Acremonium sp. andvarious other Hyphomycetes4,5) are able to producepetaibols.Here we report the occurrence of chrysospermins A-D (1-4;Fig.1) in the fruit body of Xerocomus langbianensis.III. Material and methods:Specimens of Xerocomus langbianensis were collected inthe pine forest near Dalat (South Central Vietnam)7) .Taxonomical studies were carried according Roef Singer(1987). A old fruiting body of this mushroom waslyophilized to yield 120g dry material and researched thebioactive compound according Udo Graefer (1995).IV. Results and discussion1. Xerocomus langbianensisCap 8 – 30 cm wide; convex, becoming nearly flat; smoothto somewhat pitted, usually cracking in dry weather as wellas when old; brown or cinnamon-buff. Flesh white; capskin parenchyma. Tubes: sunken around stalk, yellow.Stalk 8 – 20 cm long, 3 – 5 cm thick and cylandric orbulbous in the middle. Flesh white. Spores: 11 – 14 x 3 – 4m cylindric eliptical, smooth with several oil drops inside.Good taste. Growing season: raining time. on the groundunder conifers in Dalat, Lamdong province. (Pic. 1, 2)It was extracted five-times for each 24 hours by 500 mlCHCl3/MeOH (1:1, v/v), and the combined extracts wereevaporated in vacuo. The residue (5.4 g) was subjected tocolumn chromatography on silicagel 60 (0.063 – 0.1 mm,column 4 x 80 cm ). The components of the mixture wereeluted in order of their polarity by CHCl3, CHCl3/MeOH(9:1) and CHCl3/MeOH (8:2). 20 ml fractions werecollected and evaporated. Samples of the residues werespotted on TLC sheets (silicagel 60, Merck) and developedby CHCl3/MeOH, 9:1). Subsequently the chromatogramswere stained by 1% vanillin in conc. H2SO4. Firstergosterol and other terpenoid materials were eluted. Laterfractions occurrence containing linolic acid, cerebroside B,honogerine lipids. Finally a fraction occurred with Rf 0.1 o-n TLC (see above) staining reddish with the above sprayreagent (yield: 8 mg).The sample this obtained was analyzed by electrospraytriple quadrupole mass spectrometry (Quattro instrument,VG Biotech, Altrincham, England). Pseudomolecular ionswith m/z 1898, [M+H]+ (1), m/z 1912 [M+H]+ (2,3) andm/z 1926 [M+H]+ (4) were readily disclosed ascharacteristics of the chrysospermins A-D (1-4). (see c.f.Fig. 2: FAB-MS of 2).Figure 1: Amino acid sequences of chrysospermins A (1),B (2), C (3), D (4) and boletusin (5):1 AcPhe Aib Ser Aib Aib Leu Gln Gly Aib Aiib Ala AlaAib Pro Aib Aib Aib Gln Trpol2 AcPhe Aib Ser Aib Aib Leu Gln Gly Aib Aib Ala AlaAib Jpro Iva Aib Aib Gln Trpol3 AcPhe Aib Ser Aib Iva Leu Gln Gly Aib Aib Ala Ala AibPro Aib Aib Aib Aln Trpol4 Acphe Aib Ser Aib Iva Leu Gln Gly Aib Aib Ala Ala AibPro Iva Aib Aib Gln Trpol5 AcPhe Aib Ala Iva Leu Gln Gly Aib Aib Ala ala Aib ProAib Aib Aib Gln TrpolThe resuls with Xerocomus langbianensis confirm theoccurrence of chrysospermins3) in fruit bodies ofbasidiomycetes. Sang- Jun Lee et al6) reported also in 1999about is ...