Hydroxy Fatty Acid Glycosides of Sophorose From Torulopsis Magnoliae

Abstract

The oil forlned during fernlentation by a strain of Torldopsis nrag~roliae consisted 1nai111y of partly acetylated 2-0-0-D-glucopyranosyl-D-glucopyrano units attached 0-glycosidically to 17-L-hydroxyoctadec;unoic ancl 17-L-hydroxy-9-octadecenoic acids.A strain of osmophilic yeast, Torulopsis magnoliae, isolated fro111 SOW thistle petals, was found to produce (1) an extracellular, heavier than water oil. The main components of the oil are now shown to be glycolipids (I and 11) consisting of 2-0-/3-D-glucopyranosyl-D-glucopyranose units linked /3-glycosidically to 17-L-hydroxyoctadecanoic and 17-Lhydroxy-9-octadecenoic acids, the sugar moieties being partly acetylated.The oil was labile both to acid and alkali. I-Iot methanolic sodium methoxide removed the acetyl groups, which constituted about 1.5 substituent groups per mole (the positions of these substituents were not determined). The deacetylated product, after fractionation, yielded a solid (I and II),which contained allnost equal quantities of lactonic and acidic glycolipids, and it was on this mixture that the characterization studies of the sugar portion were carried out.Acid methanolysis of the deacetylated oil yielded 2 moles of methyl-a-D-glucopyranoside and 1 mole of a mixture of fatty acid methyl esters. Gas -liquid phase chromatography of the esters on a silicone column showed one principal peak a t the C20 saturated position with a shoulder suggesting partial resolution of saturated and unsaturated esters (2). However, on a butanediol succinate colulnn (3) no peaks appeared after 2 hours (normal emergence time for a C20 ester was 30 minutes). The properties suggested that the major con~pounds present were C18 esters containing a polar substituent, such as a llydroxyl group (4) and the presence of the latter group was confirmed by infrared spectroscopy. From the quantity of permanganate-periodate reagent (5) consumed, the mixture was shown to contain 65% of nlonoolefinic ester. Fractional crystallization of the methyl esters also yielded 65% unsaturated and 35% saturated ester. However, later fermentations contained only about 10yo of the saturated material. Catalytic hydrogenation showed that the unsaturated c 1 8 ester (IV) contained one double bond and the product obtained was identical with the saturated Cl8 con~ponent (111). The position of the hydroxyl group in these compounds was shown to be a t C17, by the formation of 17-0x0-stearic acid (V) when the saturated acid was oxidized with chromium trioxide. An authentic specimen of V was synthesized by the method of Bergstrom et al. (6) from 15-bromopentadecanoic acid. The latter was prepared from 15-hydroxypentadecanoic acid which was in turn obtained from the 15,lB-dihydroxypalinitic acid described by Leinieux (7).The unsaturated component (IV) was shown to be 17-hydroxy-9-octadecenoic acid methyl ester since the acid on oxidation with permanganate-periodate (5) yielded azelaic 1Manz4script received Decevlber SO, 1960.

Structure and reactions of lactonic and acidic sophorosides of 17-hydroxyoctadecanoic acid

“…When this work was almost complete Jones (5) (using a strain of Torulopsis obtained from us) isolated a lactone and proposed that it had structure (9), which differs from our structure (1) in the attachment of the ester linkages to ring B. In 9, hydroxyl-4 of ring B is not esterified but a n acetate is present at OH-3 and the fatty acid carboxyl is linked to OH-6.…”

“…Oxidation ofLactone (1) Lactone (I) contains one readily cleavable glycol group since, on oxidation with lead tetraacetate in acetic acid in the presence of potassium acetate (7), or with sodium periodate, one mole of oxidant is used per mole of 1 (Tables I and 11). …”

The effect of medium composition on the production of sophorolipids and the tensiometric properties by Starmerella bombicola MTCC 1910

“…The extracellular production of glycolipids was first studied and reported in the year 1961 by Candida species 6 . The culture medium constituents were glucose, yeast extract and urea.…”

Production and Characterization of a Biosurfactant fromCyberlindnera samutprakarnensisJP52T

“…1,2) Sophorolipids are glycolipid-type biosurfactants, formerly known as sophorosides, that are excreted into the culture medium by Candida and related yeast genera. 3) Torulopsis magnolia, now known as Candida apicola, was the first reported sophorolipid-producing yeast 4) and the structure of its sophorolipid mixture was elucidated to be a partially acetylated 2-O--D-glucopyranosyl-Dglucopyranose unit (sophorose) attached -glycosidically to 17-L-hydroxyoctadecanoic or 17-L-hydroxy-Á9-octadecanoic acid. 5,6) Later, Candida bogoriensis (now known as Rhodotorula bogoriensis) was found to be a sophorolipid-producing yeast, the product obtained being composed of a sophorose unit linked to 13-hydroxydocosanoic acid.…”