Characteristic fragmentation of bacteriohopanepolyols during atmospheric pressure chemical ionisation liquid chromatography/ion trap mass spectrometry

Abstract

Bacteriohopanepolyols (BHPs) fragment via characteristic pathways during atmospheric pressure chemical ionisation liquid chromatography/ion trap mass spectrometry (APCI-LC/MS(n)). Comparison of the MS(2) spectra of bacteriohopane-32,33,34,35-tetrol (BHT) and 2 beta-methylbacteriohopane-32,33,34,35-tetrol has confirmed the previously proposed ring-C cleavage occurring between C-9 and 11 and C-8 and 14. This fragmentation, diagnostic of all hopanoids, also occurs in BHPs containing an amino group (-NH(2)) at C-35 although the higher relative stability of the ion limits this fragmentation to a minor process after protonation of the basic nitrogen function. Studies of a number of cell cultures including a prochlorophyte (Prochlorothrix hollandica) and a cyanobacterium (Chlorogloeopsis LA) demonstrate the power of this technique to detect composite BHPs with a complex biological functionality at C-35. We also report the first observation of intact pentafunctionalised bacteriohopanepolyols using this method.

Identification of the Bacteriochlorophylls, Carotenoids, Quinones, Lipids, and Hopanoids of "Candidatus Chloracidobacterium thermophilum"

“…The APCI parameters were as follows: gas temperature, 325°C; vaporizer temperature, 350°C; drying gas (N 2 ) flow, 6 liters min Ϫ1 ; nebulizer (N 2 ) flow, 30 liter min Ϫ1 ; capillary voltage, 1,200 V; corona needle, 4 A; and fragmentor, 150 V. Data were recorded by scanning from m/z 100 to 1,600. Identification of the hopanoids was based on their exact mass and by comparison of retention times and mass spectra with published data (68,69).…”

Diverse capacity for 2-methylhopanoid production correlates with a specific ecological niche

“…The linear gradient was then set to 30% (v) of isopropyl alcohol at 0.19 ml min À 1 over 10 min and maintained for 5 min. The column was subsequently eluted using a linear gradient up to 80% isopropyl alcohol (v) over 1 min at a flow rate of 0.15 ml min (Talbot, Squier, et al, 2003;Talbot, Summons, et al, 2003;Talbot et al, 2007b).…”

Rare bacteriohopanepolyols as markers for an autotrophic, intra-aerobic methanotroph

“…(Hermann et al, 1996), in Frateuria aurantia (Joyeux et al, 2004), and in trace amounts in the cyanobacterium Chlorogloeopsis sp. LA (Talbot et al, 2003b). Methylomirabilis spp.…”