Methyl lithocholate

It has been claimed that the elimination of tosylates of 3a-alcohols in 5jS-series gives 3-oleflns with high selectivity. However, the homogeneity of these products is questionable, in view of recent findings concerning the ehmination of 3-chloro compounds (see below) and Fieser s results with the elimination of methyl lithocholate tosylate (ref. 232, cf. ref. 233). Neutral alumina may also be used to effect elimination of tosylates of 3j5-alcohols if the alumina is pretreated with potassium hydroxide the inverted alcohol is the predominant product. 

Methyl 3a,6a-dihydroxycholanate, 240 1-Methylestrone 3-methyl ether, 10, 27 4b/3-Methyl-7-ethylenedioxy-1,2,3,4, 4a ,4b/3,5,6,7,8,10,1 Oaa-dodecahydro-phenanthrene-1 /3,4/3-diol, 236 14C-Methyl iodide, 211 ds-Methyl iodide, 210, 214 Methyl lithocholate tosylate, 329 1-Methyl-19-nortestosterone, 27 6a-Methylprednisolone, 410 6a-Methylprednisolone BMD, 410 16/3-Methylprednisone, 87 18-Methylpregn-4-ene-3/3,17a,20f-triol, 243 20-Methylpregn-5-en-3/3-ol, 415 17a-Methylpregnenolone acetate, 48 17a-Methyltestosterone, 438 16/3-Methyl- 11a,17a,21 -trihydroxy- 5 /3-pregnane-3,20-dione 21-acetate, 299, 300 20-Methyl-3/3-trityloxypregn-5-ene, 415 3/3-Methoxycholestane, 136 1-Methoxycyclohexene, 18 3-Methoxyestra-3,5(10)-diene, 18, 27... 

Methyl lithocholate (LMC) Norlithocholic acid (NLCA) Homolithocholic acid (HECA) Bishomolithocholic acid (BHLCA) 3-Epilithocholic acid (3ELCA)... 

Partial separations of the substituted methyl allocholanoates have now been achieved by crystallization. Kallner (41, 45) has reported the removal of 82% of the radioactivity after three crystallizations of a mixture of methyl allolithocholate- H and methyl lithocholate 90% of the tritium was removed by several crystallizations of a mixture of methyl lithocholate- H and allolithocholate. Similarly, more than 90% of the radioactivity was removed from a mixture of methyl deoxycholate- H and allodeoxycholate after three crystallizations from aqueous acetic acid or aqueous methanol. Methyl 3/3,12a-dihydroxy-5 -cholanate was separated from methyl deoxy-cholate by crystallization from aqueous methanol. Thomas et al. (46) reported the separation of 3a,6/3-dihydroxy-5 - or 3a,6a-dihydroxy-5 -cholanoic acid from 3a,6/3-dihydroxy-5 -cholanoic acid by crystallization from aqueous acetone or a mixture of methanol, ether, and hexane. 

With this solvent Anasil B is used as adsorbent. Mobilities are given relative to that of methyl lithocholate (cf. Table VIII). 

Fig. 2. Mass spectra of methyl lithocholate (1), its trifiuoroacetate (3) and trimethylsilyl ether (2), and of the trifluoro-acetate of the epimeric methyl 3 -hydroxy-5 -cholanoate (4) and the gas chromatographic decomposition product (5) of this compound. The letters in this and the following figures refer to the fragmentation modes illustrated in Fig. 1 and listed in Table III.

Methyl oleate Methyl oleate Methyl lithocholate Methyl lithocholate Methyl lithocholate Methyl lithocholate Methyl deoxycholate Methyl deoxycholate Methyl deoxycholate Lithocholic acid Anasil B Silica gel G Silica gel G Silica gel G Silica gel G Anasil B Silica gel G AnasU B Silica gel G Silica gel G... 

Lithocholic acid methyl ester] (triterpene) Human animal origin cf. oleanolic acid PKA (rat) (9)... 

A modified Huang-Minlon reduction was found advantageous in the conversion of methyl eholate to lithocholic acid without purification of intermediates. The 3-hydroxyl group (equatorial) is selectively succinoylated, the hydroxyl functions... 

Proteasome regulators Lithocholic acid derivatives 3a-0-Pimeloyl-lithocholic acid methyl ester Isosteric isomer... 

Van den Bosch and Claes (19) have reported that A -methyl neomycin, a compound with no antibiotic properties, will lower cholesterol levels in man and in chicks. In man, A -methyl neomycin produces a sharp rise in both the fecal bile acids and neutral steroids. The amount of excreted lithocholic and... 

FIGURE 14.4 Lithocholic acid methyl ester TMS ether. (A) EI-MS. The [M] ion is at 462, [M-CHs] at 447, [M-TMSOH] at 372, [M-CH3-TMS0]+ at 357, ABCD+ ion at 257, and the ABC ion at 215. (B) GC-APCI-MS profiie. (C) Upper trace GC-APCI-MS and lower trace GC-APCI-MS . The spectrum in (A) was recorded on a singie quadrupole instrument, while (B) and (C) were recorded on a quadrupole time-of-flight (Q-TOF)-type instrument. The MS spectrum was recorded by raising the coiiision energy across the collision ceii but without mass selection. 

With a purified enzyme preparation from Clostridium perfringens, Roovers et al. (36) cleave conjugated bile acids directly in plasma. Proteins are then precipitated with Ba(OH)2-saturated ethanol (123) and the supernatant is taken to near dryness. The residue is dissolved in a toluene-isopropanol-methanol-30 % aqueous NaOH (10 20 20 6, v/v) mixture, water is added, and neutral lipids removed by light petroleum extraction. Bile acids are then obtained by acidification and diethyl ether extraction. The bile acids are then methylated and analyzed as above except that the bile acid methyl esters are acetylated before chromatography on 1 % XE-60 columns at 250°C. With this column the following retention times relative to that of the diacetoxy derivative of methyl deoxycholate were found for the following acetate methyl ester derivatives lithocholic, 0.60 23-nor-deoxycholic acid (internal standard), 0.77 chenodeoxycholic acid, 1.24 and cholic acid, 1.88. The deoxycholic acid derivative was eluted after 9.0 min and methyl 5 3-cholanoate after 0.32 min. 

Fig. 7. The infrared spectra of bile acids. (A) Cholanic acid, crystallized from a melt. (B) Lithocholic acid, Nujol mull. (C) Deoxycholic acid, Nujol mull—glassy amorphous melt. Asterisks indicate Nujol bands superimposed on methyl and methylene bands of lithocholic and deoxycholic acid.

Fig. 9. Spectra of the common bile acids in C HaO H. (A) Cholanic acid. 18 and 19 refer to signals from protons of C 18 and C-19 angular methyl groups. The large peak between 7.5 and 9 ppm is due to the protons of the steroid nucleus. Protons of the C-23 Hz can be identified at about 7.8 ppm. Contaminating methanol protons are seen at 6.7 and 5.2 ppm in all spectra. (B) Lithocholic acid. The small broad peak at 6.5 is due to the proton at C-3. (C) Deoxycholic acid. Small peaks due to the protons attached to the rings at the C-12 and -3 position are noted at about 6,05 and 6.5 ppm. (D) Chenodeoxycholic acid. Small peaks due to the protons attached to the steroid nucleus at position C-7 and C-3 are noted at 6.23 and 6.6 ppm. (E) Cholic acid. Peaks are due to the protons attached to the nucleus at position C-3, -7, and -12 are noted at 6.6, 6.2, and about 6 ppm. All spectra were taken at 33.4 C (67).

Lithocholic acid 6016 l-(3-Mercapto-2-methyl-l- 4-Methoxy-7 -methyl-5H-furo [3,2-g] ... 

---