Brassicasterol: Difference between revisions

| verifiedrevid = 443427373

| Name = Brassicasterol

| ImageFile = brassicasterol.svg

| ImageSize = 200px

| ImageName = Brassicasterol

| IUPACName = 24-methyl cholest-5,22-dien-3β-ol

| OtherNames = brassicasterol<br />(3β,22E)-ergosta-5,22-dien-3-ol<br />24β-methylcholesta-5,22-dien-3 beta-ol<br />ergosta-5,22-dien-3β-ol

| Section1 = {{Chembox Identifiers

| UNII_Ref = {{fdacite|correct|FDA}}

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| Section2 = {{Chembox Properties

| C=28|H=46|O=1

| Appearance = White solid

| Density =

| Solubility =

| MeltingPt = 150-151 °C

| BoilingPt =

| Section7 = {{Chembox Hazards

| ExternalMSDS =

| MainHazards =

| FlashPt = Non-flammable

| RPhrases =

| SPhrases =

| Section8 = {{Chembox Related

| Function = Sterols

| OtherFunctn = [[cholesterol]]<br />[[β-sitosterol]]<br />[[campesterol]]<br />[[stigmasterol]]

'''Brassicasterol''' (24-methyl cholest-5,22-dien-3β-ol) is a 28-[[carbon]] [[sterol]] synthesised by several [[unicellular]] [[algae]] ([[phytoplankton]]) and some terrestrial plants, ''e.g.'', [[oilseed rape]]. This compound has frequently been used as a [[biomarker]] for the presence of (marine) algal matter in the [[ecosystem|environment]].

Brassicasterol has a low water [[solubility]] and, as a consequence, a high [[Partition coefficient|octanol – water partition coefficient]] (Kow = ??). This means that, in most environmental systems, brassicasterol will be associated with the solid phase.

Since the [[molecule]] has a [[hydroxyl]] (-OH) group, it is frequently bound to other [[lipids]] including [[glycerol]]s; most analytical methods, therefore, utilise a strong [[alkali]] (KOH or NaOH) to [[saponify]] the [[ester]] linkages. Typical extraction [[solvents]] include 6% KOH in [[methanol]]. The free [[sterols]] are then separated from the [[polar lipids]] by partitioning into a less polar solvent (''e.g'', [[hexane]]). Prior to analysis, the hydroxyl group is frequently derivatised with [[BSTFA]] (bis-trimethyl silyl trifluoroacetamide) to replace the hydrogen with the less exchangeable [[trimethylsilyl]] (TMS) group. Instrumental analysis is frequently conducted on [[gas chromatograph]] (GC) with either a [[flame ionisation detector]] (FID) or [[mass spectrometer]] (MS). The [[mass spectrum]] for the TMS ether of brassicasterol can be seen in the Figure.<br />

[[Image:mass spectrum brassicasterol.png|Mass fragmentation pattern for brassicasterol at 70eV on a Fisons MD800 mass spectrometer]]

==Formation and occurrence==

===Algal sources===

|''Gonyaulax'' spp||100||0||0||0||0||0||0||0||0

|''Peridinium foliaceum''||100||0||0||0||0||0||0||0||0

|''Gonyaulax diegensis''||39||0||0||0||0||0||0||29||32

|''Pyrocystis lunula''||76||6||0||2||1||0||0||0||15

|''Gonyaulax polygramma''||36||1||0||9||7||0||0||0||47

|''[[Gymnodinium]] wilczeki''||26||39||0||35||1||0||0||0||0

|''Glenodinium hallii''||8||50||0||0||0||42||0||0||0

|''[[Noctiluca milaris]]''||0||1||1||5||73||0||6||0||14

|''Gymnodinium simplex''||0||0||0||0||53||0||0||0||47

|''Prorocentrum cordatum''||7||0||0||0||5||0||63||0||25

:E = BRASSICASTEROL

==References==

[[Category:Sterols]]

[[Category:Alcohols]]

[[nl:Brassicasterol]]

[[ja:ブラシカステロール]]

[[zh:菜籽固醇]]