Anti-dandruff sugars

Abstract

The invention relates to the cosmetic use of at least one compounds according to the following formula (I), as an anti-dandruff agent or for preventing and/or treating scalp dandruff: where “sugar” denotes a monosaccharide residue chosen from rhamnose, xylose, fucose, mannose, lyxose, and arabinose; where R, substituting the anomeric oxygen in the sugar (represented by “O” in formula (I)), denotes a radical comprising 6 to 38 carbon atoms chosen from: —a linear or branched, saturated alkyl radical; —a linear or branched, alkenyl radical; said linear or branched saturated alkyl radical being optionally substituted by at least one OH and/or NH2 function; —if “sugar” denotes a mannose residue, R denotes a linear C6-C38 alkyl radical, substituted by at least one OH function or an NH2 function; and the salts and solvates and/or optical isomers thereof, alone or in a mixture, particularly racemic forms. The invention also relates to compounds according to formula (I), and cosmetic compositions containing same. ##STR00001##

Claims

1. A cosmetic treatment method for eliminating and/or reducing dandruff, which comprises applying on the scalp at least one compound according to the following formula (I), as an anti-dandruff agent or for preventing and/or treating scalp dandruff: ##STR00044## where “sugar” denotes a monosaccharide residue chosen from rhamnose, xylose, fucose, mannose, lyxose, and arabinose; where R, substituting the anomeric oxygen in the sugar (represented by “O” in formula (I)), denotes a radical comprising 6 to 38 carbon atoms chosen from: a linear or branched, saturated alkyl radical; a linear or branched, alkenyl radical; said linear or branched saturated alkyl radical being optionally substituted by at least one OH and/or NH.sub.2 function; if “sugar” denotes a mannose residue, R denotes a C6-C38 alkyl radical; substituted by at least one OH function or a NH.sub.2 function; if “sugar” denotes a arabinose residue, R denotes a C6-C38 linear alkyl radical substituted by an OH function or a C9-C38 linear alkyl radical substituted by a NH.sub.2 function; and the salts and solvates and/or optical isomers thereof, alone or in a mixture.

2. The cosmetic treatment method Use according to claim 1, wherein, in compound (I), the sugar is: L-rhamnose, D-xylose, L-fucose, D-mannose, D-lyxose, or arabinose.

3. The cosmetic treatment method according to claim 1, wherein the compound according to formula (I) comprises a radical R comprising 8 to 30 carbon atoms, provided that if “sugar” denotes an arabinose residue and R1 denotes a linear alkyl radical substituted by a NH.sub.2 function, said linear alkyl radical comprise at least 9 carbon atoms.

4. The cosmetic treatment method according to claim 1, wherein the compound according to formula (I) is represented by the following formula (II): ##STR00045## and the salts and solvates, and/or optical isomers thereof, alone or in a mixture, where R1, substituting anomeric oxygen, denotes: a linear or branched, saturated C8-C22 alkyl radical; a linear or branched, C8-C22 alkenyl radical; a linear C8-C22 alkyl radical, substituted by an OH function or a NH.sub.2 function; if “sugar” denotes a D-mannose residue, R1 denotes a linear C8-C22 alkyl radical, substituted by an OH or NH.sub.2 function if “sugar” denotes an arabinose residue, R1 denotes a linear C8-C22 alkyl radical substituted by an OH or a linear C9-C22 alkyl radical substituted by a NH.sub.2 function.

5. The cosmetic treatment method according to claim 4, wherein, in the compound according to formula (II), R1 denotes a C8-C20 saturated linear alkyl radical provided that if “sugar” denotes an arabinose residue and R1 denotes a linear alkyl radical substituted by a NH.sub.2 function, said linear alkyl radical comprise at least 9 carbon atoms.

6. The cosmetic treatment method according to claim 4, wherein the compound according to formula (II) is chosen from: hexadecyl 6-deoxy-L-mannopyranoside hexadecyl D-xylopyranoside hexadecyl 6-deoxy-L-galactopyranoside octadecyl 6-deoxy-L-mannopyranoside decyl 6-deoxy-L-galactopyranoside decyl 6-deoxy-L-mannopyranoside dodecyl 6-deoxy-L-mannopyranoside decyl D-xylopyranoside docosyl 6-deoxy-L-mannopyranoside (3S)-3,7-dimethyloct-6-en-1-yl D-xylopyranoside 9-hydroxynonyl 6-deoxy-L-mannopyranoside 9-hydroxynonyl-D-mannopyranoside 2-hydroxydecyl D-xylopyranoside octyl 6-deoxy-L-mannopyranoside eicosyl 6-deoxy-L-mannopyranoside dodecyl 6-deoxy-L-mannopyranoside tetradecyl 6-deoxy-L-mannopyranoside decyl D-lyxopyranoside, and mixtures thereof.

7. The cosmetic treatment method according to claim 1, wherein the compounds according to formula (I) are represented by the following formula (III): ##STR00046## and the salts and solvates and/or optical isomers thereof, alone or in a mixture, where “sugar” denotes a monosaccharide residue chosen from rhamnose, xylose, fucose, mannose, lyxose, and arabinose; R1 denotes a linear C2-C18 alkyl radical; R2 denotes a linear C2-C18 alkyl radical if “sugar” denotes an arabinose residue, R1 denotes a linear C8-C22 alkyl radical substituted by an OH or a linear C9-C22 alkyl radical substituted by a NH.sub.2 function.

8. The cosmetic treatment method according to claim 7, wherein: the compound according to formula (III) is chosen from: 2-octyltetradecyl 6-deoxy-L-mannopyranoside 2-octyldecyl 6-deoxy-L-mannopyranoside 2-hexyldecyl 6-deoxy-L-mannopyranoside 2-octyldodecyl 6-deoxy-L-mannopyranoside 2-decyltetradecyl 6-deoxy-L-mannopyranoside 2-octyltetradecyl D-lyxopyranoside 2-octyldodecyl D-lyxopyranoside 2-decyltetradecyl D-lyxopyranoside 2-hexyldecyl 6-deoxy-L-galactopyranoside 2-octyldodecyl 6-deoxy-L-galactopyranoside 2-decyltetradecyl 6-deoxy-L-galactopyranoside 2-octyltetradecyl D-mannopyranoside 2-octyldodecyl D-mannopyranoside 2-decyltetradecyl D-mannopyranoside and mixtures thereof.

9. The cosmetic treatment method according to claim 1, wherein one or a plurality of said at least one compound are present in a cosmetic composition containing a physiologically acceptable medium.

10. A compound according to the following formula (I′): ##STR00047## and the salts and solvates and/or optical isomers thereof, alone or in a mixture, where: the sugar is a rhamnose and R is a C6-C38 linear alkyl radical substituted by an OH function; the sugar is a rhamnose and R is a C8-C38 linear alkyl radical substituted by a NH.sub.2 function; the sugar is a mannose and R is a C8-C38 linear alkyl radical substituted by an OH function; the sugar is a mannose and R is a C14-C38 saturated linear alkyl radical substituted by a NH.sub.2 function; the sugar is a xylose and R is a C6-C38 linear alkyl radical substituted by an OH function; the sugar is a xylose and R is a C9-C38 linear alkyl radical substituted by a NH.sub.2 function; the sugar is a lyxose and R is a C6-C38 linear alkyl radical substituted by an OH function; the sugar is a lyxose and R is a C8-C38 linear alkyl radical substituted by a NH.sub.2 function; the sugar is a fucose and R is a C6-C38 linear alkyl radical substituted by an OH function; the sugar is a fucose and R is a C9-C38 linear alkyl radical substituted by a NH.sub.2 function; the sugar is an arabinose and R is a C6-C38 linear alkyl radical substituted by an OH function; the sugar is an arabinose and R is a C9-C38 linear alkyl radical substituted by a NH.sub.2 function; or the sugar denotes a monosaccharide residue chosen from rhamnose, fucose, lyxose, and arabinose, and R represents: ##STR00048## where R1 denotes a linear C2-C18 alkyl radical; and R2 denotes a linear C2-C18 alkyl radical, if “sugar” denotes an arabinose residue, R1 denotes, a linear C8-C22 alkyl radical substituted by an OH or a linear C9-C22 alkyl radical substituted by a NH.sub.2 function.

11. The compound according to claim 10, being chosen from the following compounds 9-hydroxynonyl 6-deoxy-L-mannopyranoside; 9-hydroxynonyl-D-mannopyranoside; 2-hydroxydecyl D-xylopyranoside; 2-octyltetradecyl 6-deoxy-L-mannopyranoside; 2-octyldecyl 6-deoxy-L-mannopyranoside; 2-hexyldecyl 6-deoxy-L-mannopyranoside; 2-octyldodecyl 6-deoxy-L-mannopyranoside; 2-decyltetradecyl 6-deoxy-L-mannopyranoside; 2-octyltetradecyl D-lyxopyranoside; 2-octyldodecyl D-lyxopyranoside; 2-decyltetradecyl D-lyxopyranoside; 2-hexyldecyl 6-deoxy-L-galactopyranoside; 2-octyldodecyl 6-deoxy-L-galactopyranoside; 2-decyltetradecyl 6-deoxy-L-galactopyranoside; 2-octyltetradecyl D-mannopyranoside; 2-octyldodecyl D-mannopyranoside; 2-decyltetradecyl D-mannopyranoside.

12. A cosmetic composition which comprises at least one compound as defined according to claim 10 and a physiologically acceptable medium.

13. A cosmetic treatment method for eliminating and/or reducing dandruff, which comprises the application, on the scalp, of a cosmetic composition containing said at least one compound according to claim 2.

14. The cosmetic treatment method according to claim 2, wherein the compound according to formula (I) comprises a radical R comprising 8 to 30 carbon atoms provided that if “sugar” denotes an arabinose residue and R1 denotes a linear alkyl radical substituted by a NH.sub.2 function, said linear alkyl radical comprise at least 9 carbon atoms.

15. The cosmetic treatment method according to claim 1, wherein, in compound (I), the sugar is: chosen from: 6-deoxy-L-mannopyranoside; 6-deoxy-L-galactopyranoside; D-xylopyranoside; D-lyxopyranoside; and L-arabinopyranoside.

16. The cosmetic treatment method according to claim 2, wherein the compound according to formula (I) is represented by the following formula (II): ##STR00049## and the salts and solvates, and/or optical isomers thereof, alone or in a mixture, where R1, substituting anomeric oxygen, denotes: a linear or branched, saturated C8-C22 alkyl radical; a linear or branched, C8-C22 alkenyl radical; a linear C8-C22 alkyl radical, substituted by an OH function or NH.sub.2 function; if “sugar” denotes a D-mannose residue, R1 denotes a linear C8-C22 alkyl radical, substituted by an OH or NH.sub.2 function if “sugar” denotes an arabinose residue, R1 denotes a linear C8-C22 alkyl radical substituted by an OH or a linear C9-C22 alkyl radical substituted by a NH.sub.2 function.

17. The cosmetic treatment method according to claim 2, wherein, in the compound according to formula (I), R denotes a C8-C20 saturated linear alkyl radical, provided that if “sugar” denotes an arabinose residue and R1 denotes a linear alkyl radical substituted by a NH.sub.2 function, said linear alkyl radical comprise at least 9 carbon atoms.

18. The cosmetic treatment method according to claim 3, wherein, in the compound according to formula (I), R denotes a C8-C20 saturated linear alkyl radical, provided that if “sugar” denotes an arabinose residue and R1 denotes a linear alkyl radical substituted by a NH.sub.2 function, said linear alkyl radical comprise at least 9 carbon atoms.

19. The cosmetic treatment method according to claim 4, wherein, in the compound according to formula (II), R1 denotes a C8-C20 saturated linear alkyl radical, provided that if “sugar” denotes an arabinose residue and R1 denotes a linear alkyl radical substituted by a NH.sub.2 function, said linear alkyl radical comprise at least 9 carbon atoms.

20. The cosmetic treatment method according to claim 2, wherein the compound according to formula (I) is chosen from: hexadecyl 6-deoxy-L-mannopyranoside hexadecyl D-xylopyranoside hexadecyl 6-deoxy-L-galactopyranoside octadecyl 6-deoxy-L-mannopyranoside decyl 6-deoxy-L-galactopyranoside decyl 6-deoxy-L-mannopyranoside dodecyl 6-deoxy-L-mannopyranoside decyl D-xylopyranoside docosyl 6-deoxy-L-mannopyranoside (3S)-3,7-dimethyl oct-6-en-1-yl D-xylopyranoside 9-hydroxynonyl 6-deoxy-L-mannopyranoside 9-hydroxynonyl-D-mannopyranoside 2-hydroxydecyl D-xylopyranoside octyl 6-deoxy-L-mannopyranoside eicosyl 6-deoxy-L-mannopyranoside dodecyl 6-deoxy-L-mannopyranoside tetradecyl 6-deoxy-L-mannopyranoside decyl D-lyxopyranoside, and mixtures thereof.

Description

EXAMPLES

A—Examples of Synthesis of Compounds According to the Invention

(1) General Procedure:

(2) ##STR00026##

(3) The alcohol (3 eq) is previously heated to a temperature between 40° C. and 90° C. and the sugar (1 eq) and an acidic catalyst, such as for example a sulfonic acid (for example PTSA (paratoluene sulfonic acid), methanesulfonic acid, etc.), hydrochloric acid, sulfuric acid, montmorillonite, acidic resin such as DOWEX, carboxylic acid (citric acid, lactic acid, etc.), (in quantities for example of 0.01 to 0.2 eq) are added. When the reaction is complete (from 1 hour to 48 hours), the reaction medium is cooled, washed and purified by means of silica gel chromatography and/or crystallization.

Example A-1:—hexadecyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(4) ##STR00027##

(5) Synthesis described in International Journal of Cosmetic Science 2001, 23, 363-368.

Example A-2:—hexadecyl D-xylopyranoside (xylose sugar)

(6) ##STR00028##

(7) Hexadecanol: 10 g, 41.25 mmol 2.4 eq,

(8) D-xylose: 2.5 g, 16.65 mmol 1 eq

(9) PTSA 250 mg, 1.66 mmol, 0.1 eq.

(10) Reaction time: 18 hours at 80° C.

(11) Xylose and PTSA are added in portions of 1 g+1 g+0.5 g for xylose and 0.1 g+0.1 g+0.05 g for PTSA every 2 hours. The raw product obtained is purified by means of silica gel chromatography. 1.8 g of white powder obtained (Yield=35%).

(12) 1H-NMR (400 MHz, DMSO): δ 0.9 (t, 3H), δ 1.3 (m, 27H), δ 1.5 (m, 2H), δ 2.9-3.7 (m, 10H)

(13) Mass spectrometry (ESI+/−MeOH/H.sub.2O): [M+Na].sup.+ 397

(14) Micro analyses: 66.9% C, 11.4% H, 20.2% O

Example A-3:—hexadecyl 6-deoxy-L-galactopyranoside (fucose sugar)

(15) ##STR00029##

(16) Synthesis described in FR2614024

Example A-4:—octadecyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(17) ##STR00030##

(18) 1-octadecanol: 445 mg, 1.6 mmol, 1 eq

(19) L-rhamnose monohydrate: 300 mg, 1.6 mmol, 1 eq

(20) TMSCl (chloro trimethylsilane): 1.04 mL, 8.2 mmol, 5 eq.

(21) Reaction time: 5 min.

(22) After 5 min in a microwave at 60° C. under a pressure of 6 bar, formation of a green precipitate after cooling. The precipitate is dissolved in dichloromethane, the insoluble is filtered and the whole concentrated to remove the residual TMSCl. The raw product is purified on silica gel

(23) 41 mg of white powder obtained, yield 6%

(24) Mass spectrometry: M=384.38 [M+Na]+, [M−H]−

Example A-5:—decyl 6-deoxy-L-galactopyranoside (fucose sugar)

(25) ##STR00031##

(26) decanol: 35 mL, 0.18 mol,

(27) L-fucose: 10 g, 60.9 mmol, 1 eq

(28) PTSA 1.75 g, 6.09 mmol, 0.1 eq.

(29) Reaction time: 6 hours at 80° C.

(30) 5.2 g of fine white powder obtained, yield 29%.

(31) Mass spectrometry: M=304.42 [M+Na]+ et [2M+Na]+ in positive mode and [M−H] in negative mode

Example A-6:—decyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(32) ##STR00032##

(33) decanol: 32 mL, 0.16 mol,

(34) L-rhamnose, monohydrate: 10 g, 55 mmol,

(35) PTSA 1.58 g, 5.5 mmol,

(36) Reaction time: 4 hrs 30 at 80° C.

(37) 10.52 g obtained in white paste form, yield 65%.

(38) Mass spectrometry: M=304.42 [M−H]−, [M+Na]+

Example A-7:—dodecyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(39) ##STR00033##

(40) dodecanol: 1.53 g, 8.24 mmol, 5 eq

(41) L-rhamnose monohydrate: 300 mg, 1.6 mmol, 1 eq

(42) TMSCl: 1.04 mL, 8.2 mmol, 5 eq.

(43) Reaction time: 2 hours at 80° C.

(44) 310 mg of white powder obtained, yield 56%

(45) Mass spectrometry: M=332.48 [M−H]−, [M+Na]+

Example A-8:—decyl D-xylopyranoside (xylose sugar)

(46) ##STR00034##

(47) decanol: 32 mL, 0.16 mol 2.5 eq,

(48) D-xylose: 10 g, 66.6 mmol 1 eq,

(49) PTSA 1 g, 6 mmol, 0.1 eq,

(50) Reaction time: 4 hrs 30 at 80° C.

(51) White powder obtained: 1.84 g, yield 10%

(52) Mass spectrometry: M=290.4 [M−H]−, [M+Na]+

Example A-9:—docosyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(53) ##STR00035##

(54) Docosanol: 54 g, 164 mmol 2 eq,

(55) L-rhamnose: 15 g, 82 mmol 1 eq

(56) PTSA 1.42 g, 8.23 mmol, 0.1 eq.

(57) Reaction time: 6 hours at 80° C.

(58) 14.2 g of white powder obtained, yield 36%

(59) Mass spectrometry: M=472, [M+Na]+

Example A-10:—(3S)-3,7-dimethyloct-6-en-1-yl D-xylopyranoside (xylose sugar)

(60) ##STR00036##

(61) D-xylose: 1 g, 6.7 mmol, 1 eq.

(62) Citronellol: 3.65 mL, 3 eq.

(63) PTSA: 127 mg, 0.67 mmol, 0.1 eq.

(64) Reaction time: 5 hours

(65) At the end of the reaction, water and ethyl acetate are added to the reaction medium and the product is extracted, before being purified by means of silica gel chromatography.

(66) 400 mg of a yellow oil obtained, yield 20%.

(67) Mass spectrometry: detection of expected product in quasi-molecular ion form [M+H]+ (m/z=289), et [M+Na]+ (m/z=311)

Example A-11:—9-hydroxynonyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(68) ##STR00037##

(69) A mixture containing 1,9-nonane-diol (500 mg), L-rhamnose (1.14 g, 2 equiv.) and 800 mg of Dowex 5WX2 resin in 5 mL of dioxane is heated at 75° C. for 24 hrs. After this time, the resin is filtered, the solvent is evaporated and the residue is purified by means of silica gel column chromatography (CH.sub.2Cl.sub.2/MeOH: 95/5). The product is obtained in beige paste form (950 mg, yield 17%).

Example A-12:—9-hydroxynonyl-D-mannopyranoside (mannose sugar)

(70) ##STR00038##

(71) A mixture of D-mannose (2.0 g, 11 mmol, 1 eq.) and 1,9-nonane-diol (5.34 g, 33 mmol, 3 eq.), in the presence of PTSA (210 mg, 1.1 mmol, 0.1 eq.) is heated at 80° C. for 9 hours. The PTSA is subsequently removed using an ion exchange resin and water and ethyl acetate are added to extract the product.

(72) After concentrating the organic phase, recrystallization in acetone makes it possible to obtain an analytically pure sample in white powder form (71 mg).

Example A-13:—2-hydroxydecyl D-xylopyranoside (xylose sugar)

(73) ##STR00039##

(74) A mixture of D-xylose (15 g, 99.9 mmol, 1 eq.) and decane-1,2-diol (52.15 g, 299.74 mmol, 3 eq.), in the presence of PTSA (1.72 g, 9.91 mmol, 0.1 eq.) is heated at 80° C. for 6 hours. The PTSA is subsequently removed using an ion exchange resin and water and ethyl acetate are added to extract the product.

(75) After concentrating the organic phase, recrystallization in acetone makes it possible to obtain an analytically pure sample in white powder form (10.97 g, yield 36%).

B. Examples of Synthesis of Compounds According to Formula (III)

(76) General Procedure:

(77) ##STR00040##

(78) Where Ra═H, CH2OH, Me

(79) The alcohol B (3 eq) is previously heated to a temperature between 40° C. and 90° C. and the sugar A (1 eq) and an acidic catalyst, such as for example a sulfonic acid (for example PTSA, methanesulfonic acid, etc.), hydrochloric acid, sulfuric acid, montmorillonite, acidic resin such as DOWEX, carboxylic acids (citric acid, lactic acid, etc.), (in quantities for example of 0.01 to 0.2 eq) are added. When the reaction is complete (from 1 hour to 48 hours), the reaction medium is cooled, washed and purified by means of silica gel chromatography and/or crystallization.

Example B-1: 2-hexyldecyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(80) ##STR00041##

(81) A=L-rhamnose-monohydrate: 15 g, 82.3 mmol, 1 eq

(82) B=2-hexyl-1-decanol: 66.46 g, 274.13 mmol, 3.3 eq

(83) Acidic catalyst=PTSA: 1.47 g, 9.13 mmol, 0.11 eq,

(84) Reaction time: 17 hours at 80° C.

(85) At the end of the reaction, ethyl acetate and a saturated NaHCO.sub.3 solution are added to the reaction medium and the product is extracted, before being purified by means of silica gel chromatography.

(86) 15.44 g of a colorless gel obtained, yield 48%.

(87) Mass spectrometry: detection of expected product in quasi-molecular ion form [M+NH4+]+ (m/z=406)

Example B-2: 2-octyldodecyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(88) ##STR00042##

(89) A=L-rhamnose-monohydrate: 15 g, 82.3 mmol, 1 eq

(90) B=2-octyl-1-dodecanol: 49.2 g, 164.68 mmol, 2 eq

(91) Acidic catalyst=PTSA: 1.42 g, 8.23 mmol, 0.1 eq,

(92) Reaction time: 6 hours.

(93) At the end of the reaction, purification by means of silica gel chromatography.

(94) 3.7 g of a colorless oil obtained, yield 10%.

(95) Mass spectrometry: detection of expected product in quasi-molecular ion form [M−H].sup.− (m/z=443) and [M+Na].sup.+ (m/z=467)

Example B-3: 2-decyltetradecyl 6-deoxy-L-mannopyranoside (rhamnose sugar)

(96) ##STR00043##

(97) A=L-rhamnose-monohydrate: 15 g, 82.3 mmol, 1 eq

(98) B=2-decyl-1-tetradecanol: 58.41 g, 164.7 mmol, 2 eq

(99) Acidic catalyst=PTSA: 1.42 g, 8.23 mmol, 0.1 eq,

(100) Reaction time: 6 hours at 80° C.

(101) At the end of the reaction, purification by means of silica gel chromatography.

(102) 2.6 g of a colorless oil obtained, yield 6%.

(103) Mass spectrometry: detection of expected product in quasi-molecular ion form [M−H].sup.− (m/z=449) and [M+Na+H].sup.+ (m/z=524)

(104) In the examples: TMSCL denotes Chlorotrimethylsilane; PTSA denotes trisodium 8-aminopyrene-1,3,6-trisulfonate.

C—Cosmetic Compositions According to the Invention

Example C-1: Anti-Dandruff Shampoo

(105) An anti-dandruff shampoo comprising the following ingredients is prepared:

(106) TABLE-US-00002 Sodium lauryl ether sulfate (2.2 OE) in  17 g AS aqueous solution (COGNIS TEXAPON AOS 225 UP) Cocoyl betaine in aqueous solution 2.5 g AS (COGNIS DEHYTON AB 30) Coconut oil acid monoisopropanolamide 2.0 g (GOLDSCHMIDT REWOMID V 3203) hexadecyl 6-deoxy-L-mannopyranoside 0.3 g AS Preservatives 1.1 g Perfume 0.5 Water QS 100 g

(107) Applying the shampoo on the hair and scalp helps reduce the appearance of dandruff.

Example C-2: Anti-Dandruff Lotion

(108) An anti-dandruff lotion comprising the following ingredients is prepared:

(109) TABLE-US-00003 2-hexyldecyl 6-deoxy-L-mannopyranoside (example B-1) 0.3 g AS Preservatives qs Water qs 100 g

(110) Applying the lotion on the hair and scalp helps reduce the appearance of dandruff.

Example D—Assay of Antidandruff Activity

(111) A solution containing 2% by weight of test compound is prepared in “modified Leeming and Notman liquid (MLNA)” in the following way:

(112) 0.2 g of test compound is weighed out into quantity sufficient (qs) for 10 mL of modified Leeming and Notman liquid; solubilization is carried out by heating and the use of ultrasound.

(113) The solutions of test product are twice as concentrated as the final test concentration, in order to take into account the dilution when they are brought into contact with the Malassezia suspension. By using a solution at 2%, the final concentration evaluated in the test is at 1% after the dilution.

(114) The Malassezia strains are brought into contact according to table 2 below:

(115) TABLE-US-00004 TABLE 2 Test Growth control composition Strain 0.5 mL 0.5 mL Test solution — 0.5 mL MLNA medium 0.5 mL —

(116) The mixture is stirred and deposited at the surface of the MLNA agar. It is spread, with a sterile scraper, over the entire surface before recovering the excess. It is left to incubate for at least 5 days at 30° C.

(117) The antifungal effect of the compound is evaluated via the absence of growth of the Malassezia strain tested. This inhibition is evaluated relative to the growth control. The inhibitions are scored from 0 to 3 via assessment of the density of the culture at the surface of the agar, in comparison with the growth control, in the following way:

(118) TABLE-US-00005 TABLE 3 Score Inhibition Interpretation 3 100%  No growth 2 75% Growth < in the control dish 1 25% Growth < in the control dish 0  0% Growth comparable to the control dish