Pigment or Organism Name:	Bacteriochlorophyll c (Frigaard)
Type:	biological pigment
Description:	In vivo absorbance spectrum of BChl c combined with carotenoids of unspecified type and amount


x-axis label:	wavelength
x-axis units:	nm
y-axis label:	absorbance
y-axis units:	relative
error label:	nil
error units:	nil


Source/Contact:	Niels-Ulrik Frigaard

Reference:	Frigaard, N. U., K. L. Larsen and R. P. Cox. (1996). Spectrochromatography of photosynthetic pigments as a fingerprinting technique for microbial phototrophs. FEMS Microbiology Ecology 20(2): 69-77.


Comments:	In vitro measurements via high-performance liquid chromatography and continuous monitoring of the column eluate using a diode-array spectrophotometer.  Pigments extracted with acetone:methanol and centrifugation.  10% acetone used as buffer in column injection.
	Absorbance (in vivo), A, of intact cells of Chlorobium tepidum (green sulfur bacteria) containing BChl c and carotenoids, where A(lambda) = -log10(J(lambda)/J0(lambda)), where J0(lambda) is the incident light at wavelength lambda, and J(lambda) is the transmitted or attenuated light. Aqueous buffer.
	Pigment present in Membrane Chlorosomes of C. tepidum, often in conjunction with others.  From Niels-Ulrik Frigaard email of June 3, 2004:  The spectrum of BChl c in its natural state. The sample is the light-harvesting organelle (chlorosomes) from the green sulfur bacterium Chlorobium tepidum. It contains BChl c and carotenoids. The peaks at 456 and 746 nm are due to BChl c. The shoulder around 510 nm is due to carotenoids. There is also a minute amount of BChl a around 795 nm but that does not show up much in isolated chlorosomes. The only significant difference from whole-cell material in terms of absorption is that whole cells have a little more BChl a that shows up around 810 nm (compare with the previous spectra I send you). This BChl a is separated when you isolate the chlorosomes.
	3 IS, 8-isobutyl-12-ethyl, famesyl
	Molecular image,  BChlc_Mizoguchi_1996_molec.jpg: Mizoguchi, T., K. Matsuura, K. Shimada and Y. Koyama (1996). The structure of the aggregate form of bacteriochlorophyll c showing the Qy absorption above 740 nm: a 1H-NMR study. Chemical Physics Letters 260(1-2): 153-158.
	H-NMR spectroscopy and electronic absorption spectra.  S[I, E] BChl c F, i.e. bacteriochlorophyll c (3 ~S, 8-isobutyl-12-ethyl, farnesyl), was collected by HPLC from a mixture of bacteriochlorophyll c, which was extracted from the cells of Chlorobium limicola f. sp. Thiosulfatophilum. BChl c was dissolved into a 1 : 3 mixture of methylene chloride-d2 and carbon tetrachloride, and titrated in methanol-d4.
	BChl-c absorbance peaks at 456 and 746 nm.  Shoulder around 510 nm due to carotenoids.


Keywords:	bacteriochlorophyll c, carotenoids, Chlorobium tepidum, Chlorobium limicola f., green sulfur bacteria, absorbance spectrum, photosynthetic pigment, in vivo

Datafile name:	BChlc_Frigaard_2004_spec.csv

Misc:	Molecular structure
	BChlc_Mizoguchi_1996_molec.jpg