Table 1. The content of C18:2-, C18:1-, C18:0- and C16:0-LPC in different life-cycle stages of T. cruzi.

LPC species	Picomoles of LPC per 106 cells	LPC amount (mol−17) per parasitea , b	Number of LPC molecules per parasitec	Parasite surface area (µm2)d	Number of LPC molecules per µm2 e	LPC ratio (in regard to Epi)f
C18:2-LPC ( m/z 526.4)
Epi	1.4	0.15	0.90×106	63	0.14×105	1.0
Meta	0.6	0.05	0.32×106	24	0.13×105	0.4
ICA	48.6	5.10	29.20×106	15	19.47×105	34.7
TCT	24.2	2.55	14.60×106	13	11.23×105	17.3
C18:1-LPC ( m/z 528.4)
Epi	1.1	0.11	0.66×106	63	0.10×105	1.0
Meta	0.4	0.05	0.26×106	24	0.11×105	0.4
ICA	48.7	5.00	30.00×106	15	20.00×105	44.3
TCT	17.0	1.75	10.50×106	13	8.08×105	15.5
C18:0-LPC ( m/z 530.4)
Epi	0.4	0.04	0.24×106	63	0.04×105	1.0
Meta	0.7	0.07	0.40×106	24	0.17×105	1.8
ICA	18.4	1.72	10.32×106	15	6.88×105	46.0
TCT	4.9	0.50	2.70×106	13	2.08×105	12.2
C16:0-LPC ( m/z 502.5)
Epi	n/a g	n/a	n/a	63	n/a	n/a
Meta	n/a	n/a	n/a	24	n/a	n/a
ICA	3.9	0.40	2.40×106	15	1.60×105	n/a
TCT	7.9	0.78	4.45×106	13	3.42×105	n/a

^aThe molar relative response factors (MRRF) of C10:0-LPC and LPC standards were used to calculate the amount of each LPC molecular species in Folch lower-phase fractions of T. cruzi.

^bThe number of parasites was determined before lipid extraction by counting live parasites in a hemocytometer. Values are means of three determinations. The standard deviation in all cases was <15%.

^cDetermined by multiplying the number of moles by the Avogadro's constant.

^dEstimated based on the parasite's length and diameter as determined by scanning electron microscopy, and assuming that each parasite is cylindrical, as previous described [103].

^eObtained by dividing the number of LPC molecules per cell by the surface area of each parasite form.

^fObtained by dividing the amount of picomoles of LPC per 10⁶ cells of each parasite form (column 1) by the values obtained for Epi.

^gNot analyzed due to absence or trace amounts of the compound.