Table 2.
Mass spectral data of the identified black rice bran sterols and triterpenoids
Compound | Molecular Formula | Molecular Weight | Major Fragment Ion (m/z) | |||
---|---|---|---|---|---|---|
LC-APCI-MS | GC-MS | |||||
Sterols | ||||||
24-Methylene-ergosta-5-en-3β-ol | C28H46O | 398 | 381 [M-H2O+H]+ | 398 [M]+, 383 [M-CH3]+ 365 [M-CH3-H2O]+ 314 [M-C5H9-CH3]+ 299 [M-C7H13-2H]+ 281 [M-C7H13-H2O-2H]+ 271 [M-side chain-2H] + |
||
24-Methylene-ergosta-7-en-3β-ol | C28H46O | 398 | 381 [M-H2O+H]+,399 [M+H]+ | 398 [M]+, 383 [M-CH3]+ 365 [M-CH3-H2O]+ 314 [M-C5H9-CH3]+ 299 [M-C7H13-2H]+ 271 [M-side chain-2H]+ |
||
Fucosterol | C29H48O | 412 | 395 [M-H2O+H]+ | 412 [M]+, 397 [M-CH3]+ 379 [M-CH3-H2O]+ 314 [M-C6H11-CH3]+ 299 [M-C6H11-2CH3]+ 281 [M-C6H11-2CH3-H2O]+ 229 [M-side chain-ring D cleavage-CH3-2H]+ 213 [M-side chain-ring D cleavage-CH3-H2O]+ |
||
Gramisterol | C29H48O | 412 | 395 [M-H2O+H]+ | 412 [M] +, 397 [M-CH3]+ 379 [M-CH3-H2O]+ 328 [M-C5H9-CH3]+ 285 [M-side chain-2H] + 269 [M- side chain -CH3-2H] + |
||
Campesterol | C28H48O | 400 | 383 [M-H2O+H]+ | 400 [M]+, 385 [M-CH3]+ 382 [M-H2O]+ 367 [M-CH3-H2O]+ |
||
Stigmasterol | C29H48O | 412 | 395 [M-H2O+H]+ | 412 [M]+, 397 [M-CH3]+ 394 [M-H2O]+ 369 [M-C3H5]+ 351 [M-C3H5-H2O]+ 314 [M-C7H14]+ 271 [M-side chain -2H]+ 255 [M-side chain-H2O]+ 213 [M-side chain-ring D cleavage-H2O]+ |
||
β-Sitosterol | C29H50O | 414 | 397 [M-H2O+H]+ | 414 [M]+, 399 [M-CH3]+ 396 [M-H2O]+ 381 [M-CH3-H2O]+ 329 [M-C6H13]+ 303 [M-C7H11O]+ 273 [M-side chain]+ 255 [M-side chain -H2O]+ 231 [M-side chain-ring D cleavage-CH3]+ 213 [M-side chain-ring D cleavage-CH3-H2O]+ |
||
Triterpenoids | ||||||
Cycloeucalenol | C30H50O | 426 | 409 [M-H2O+H]+, 427 [M+H]+ | 426 [M]+, 411 [M-CH3]+ 408 [M-H2O]+ 393 [M-CH3-H2O]+ 353 [M-C3H7-2CH3-H2O]+ 300 [M-C7H13-CH2-CH3]+ |
||
Lupenone | C30H48O | 424 | ND (minor compound) | 424 [M]+, 409 [M-CH3]+ 381 [M-side chain -2H]+ 368 [M-side chain-CH3]+ 342 [M-side chain-ring E cleavage]+ 313 [M-C7H11O]+ |
||
Lupeol | C30H50O | 426 | ND (minor compound) | 426 [M]+, 411 [M-CH3]+ 393 [M-CH3-H2O]+ 383 [M-side chain-2H]+ 370 [M-side chain -CH3]+ 329 [M-side chain-ring E clevage-CH3]+ |
||
24-Methylenecycloartanol | C31H52O | 440 | 423 [M-H2O+H]+,441 [M+H]+ | 440 [M]+, 425 [M-CH3]+ 422 [M-H2O]+ 407 [M-CH3-H2O]+ 397 [M-C3H7]+ 379 [M-C3H7-H2O]+ 315 [M-C9H17]+ 300 [M-C9H17-CH3]+ 285 [M-C9H17-2CH3]+ 203 [M-C9H17-5CH3]+ |