BÁO CÁO KHOA HỌC: "Xerocomus langbianensis" ppsx

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 chrysos

Xerocomus langbianensis

Trịnh Tam Kiệt

Trung tâm Công nghệ Sinh học, Đại học Quốc gia Hà Nội

Udo Graefer, Peter Saluz, B Schelegel

Viện nghiên cứu Hoá các hợp chất tự nhiên Jena,

CHLBĐức

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) Những kết quả này có thể liên quan tới việc

Xerocomus langbianensis đã bị tấn công bởi các đại diện

của nấm sinh đính bào tử

I Abstract

Chrysospermins A- D were isolated recurrently as 19-

membered peptaibols in a fruiting body of Xerocomus

langbianensis and structure was confirmed by ESI mass

spectrometry The chrysospermins A – D3) were detected

formerly in cultures of Sepedonium chrysospermum

(telemorph Apiocrea chrysosperma).The result suggested that the old Xerocomus langbianenis was infected by a

representative of the conidial fungi

II Introduction

Peptaibols such as aibelin, alamethicins, atiamoebins,

emerimicins, paracelsin, saturnisopin, suzukacillin,

trichorzianins, trikoningins, zervamicins (3) are of

considarable biological interest products because they

faciliate the transport of ions across membranes via

mechanism involving pore formation The fungus

Sepedonium chrysospermum (telemorph Apiocrea

chrysosperma) was found to produce novel antifulgal

peptides, chrysospermins A (1), B (2), C (3), D (4) as

member of the peptaibol class of linear lipophilic peptide antibiotics (3) Therefore chrysospermins promote pigment

formation by surface culture of the mold fungus Phoma

destructiva The fungus Sepedonium ampullosporum

known as the producer of the similar peptaibols

ampullosporins A- E1,2) The another filamentous fungi

such as Trichoderma herxianum, Acremonium sp and

various other Hyphomycetes4,5) are able to produce

petaibols

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 in

the pine forest near Dalat (South Central Vietnam)7)

Taxonomical studies were carried according Roef Singer (1987) A old fruiting body of this mushroom was

lyophilized to yield 120g dry material and researched the bioactive compound according Udo Graefer (1995)

IV Results and discussion

1 Xerocomus langbianensis

Cap 8 – 30 cm wide; convex, becoming nearly flat; smooth

to somewhat pitted, usually cracking in dry weather as well

as when old; brown or cinnamon-buff Flesh white; cap skin parenchyma Tubes: sunken around stalk, yellow

Stalk 8 – 20 cm long, 3 – 5 cm thick and cylandric or

bulbous 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 ground under conifers in Dalat, Lamdong province (Pic 1, 2)

It was extracted five-times for each 24 hours by 500 ml CHCl3/MeOH (1:1, v/v), and the combined extracts were evaporated in vacuo The residue (5.4 g) was subjected to column chromatography on silicagel 60 (0.063 – 0.1 mm, column 4 x 80 cm ) The components of the mixture were eluted in order of their polarity by CHCl3, CHCl3/MeOH (9:1) and CHCl3/MeOH (8:2) 20 ml fractions were

collected and evaporated Samples of the residues were spotted on TLC sheets (silicagel 60, Merck) and developed

by CHCl3/MeOH, 9:1) Subsequently the chromatograms

were stained by 1% vanillin in conc H2SO4 First

ergosterol and other terpenoid materials were eluted Later fractions occurrence containing linolic acid, cerebroside B, honogerine lipids Finally a fraction occurred with Rf 0.1

o-n TLC (see above) staio-nio-ng reddish with the above spray reagent (yield: 8 mg)

The sample this obtained was analyzed by electrospray triple quadrupole mass spectrometry (Quattro instrument,

VG Biotech, Altrincham, England) Pseudomolecular ions with m/z 1898, [M+H]+ (1), m/z 1912 [M+H]+ (2,3) and m/z 1926 [M+H]+ (4) were readily disclosed as

characteristics 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 Ala Aib Pro Aib Aib Aib Gln Trpol

2 AcPhe Aib Ser Aib Aib Leu Gln Gly Aib Aib Ala Ala Aib Jpro Iva Aib Aib Gln Trpol

3 AcPhe Aib Ser Aib Iva Leu Gln Gly Aib Aib Ala Ala Aib Pro Aib Aib Aib Aln Trpol

4 Acphe Aib Ser Aib Iva Leu Gln Gly Aib Aib Ala Ala Aib Pro Iva Aib Aib Gln Trpol

5 AcPhe Aib Ala Iva Leu Gln Gly Aib Aib Ala ala Aib Pro Aib Aib Aib Gln Trpol

The resuls with Xerocomus langbianensis confirm the

occurrence of chrysospermins3) in fruit bodies of

basidiomycetes Sang- Jun Lee et al6) reported also in 1999 about isolation of chrysospermins A-D (1-4) and boletusis

(5) from the fruit body of a mushroom Boletus sp

However, the chrysospermins have been reported as

products from submerged fermentations of Sepedonium chrysospermum (telemorph Apiocrea chrysospermum 6)) Hence, it appears as unlikely that components 1-4 are

products of fruit bodies of basidomycetes such as

Xerocomus langbianensis It can be suggested that

occurrence of peptaibols 1-4 in the fruit body of Xerocomus langbianensis was due to the infection of the fruit body by

a fungicolous connidials fungus as real producer of

chrysospermins Moreover it can be suggested that

channel-forming chrysospermum8) of a fungicolous strains9) play a role in the infection process of the fruit body

Acknowledgements

We gratefully acknowledge support of this work by DLR (Bonn, Germany) and FCI (Frankfurt/Main, Germany)

References

1) Ritzau, M et.al.:J Antibiotics 50, 722-728 (1997) 2) Kronen, M et.al.:J Antibiotics 54, 175-178 (2001) 3) Dornberger, K., Ihn, W., Ritzau, M., Grọfe, U.,

Schlegel, B., Fleck, W.F., Metzger, JW.: J Antibiot 48, 977-989 (1995)

4) Laatsch, H.: Antibase, Database of microbial

compounds Chemical Concepts, Weinheim, 2000

5) Huang, Q et al.: Chem Pharm Bull 43, 223-229 (1995)

6) Lee, S.J., Lea, W.H., ,Yun, B.S., Yoo, I.D.: J Peptide Science 5, 374-378 (1999)

7) Kiet, T.T., Dửrfelt, H.: Intern Biol Congr Hanoi, Vietnam, Abstracts 2000, pp 253-255

8) Grigoriev, P.A., Schlegel, R., Dornberger, K., Grọfe, U.: Biochem Biophys Acta 1237, 1-5 (1995)

9) Hawksworth, D.L.: In: Biology of Conidial Fungi, Vol.1, ed By Cole, G.T and Kendrick, B., Academic Press, N.Y (1981), 171-235