Table 2.

Hemoglobin Adduct Formation, Oxygen Equilibrium, and Antisickling Studies Using Homozygous Sickle Red Blood Cells at 2 mM Test Compound Concentration^a

compound	modified Hb (%)b	ΔP50 (%)c	inhibition of sickling (%)d
5-HMF	32.8 ± 1.6	33.4 ± 0.9	25.7 ± 4.4
Ester Derivatives
VZHE004	43.5 ± 8.4	44.6 ± 11.9	26.3 ± 4.4
VZHE006	50.0 ± 3.0	44.8 ± 12.9	71.6 ± 0.1
VZHE007	44.5 ± 6.0	38.9 ± 11.9	10.0 ± 5.9
VZHE014	19.7 ± 6.3	35.7 ± 8.1	8.4 ± 5.9
Alkyl Ether Derivatives
VZHE005	35.3 ± 11.6	39.4 ± 8.3	35.3 ± 6.1
VZHE011	40.4 ± 3.9	39.8 ± 0.8	58.8 ± 7.0
VZHE013	15.7 ± 4.3	24.0 ± 5.6	7.4 ± 6.9
VZHE015	39.7 ± 8.2	44.0 ± 9.7	62.9 ± 6.2
VZHE016	36.4 ± 9.7	38.4 ± 10.4	22.5 ± 8.8
Aryl Ether Derivatives
5-NMFC	40.5 ± 17.6	13.4 ± 5.7	10.3 ± 0.5
5-PMFC	60.53 ± 5.3	45.4 ± 14.6	94.7 ± 0.1
5-CMFC	26.7 ± 6.5	13.2 ± 5.2	2.0 ± 1.9

^aAll studies were conducted with SS cells suspensions (20% hematocrit) incubated with 2 mM of each test compound; the results are the mean values ± SD for three separate experiments (biological replicates). The final concentration of DMSO was <2% in all samples, including in control samples.

^bHb S adduct values obtained from HPLC elution patterns of hemolysate after incubation of compounds with SS cells.

^c

P₅₀ is the oxygen pressure at which the hemolysates are 50% saturated with oxygen. ΔP₅₀ (%) was determined as

$$\Delta P_{50}(\%)=[P_{50}\text{of lysates from untreated cells}-P_{50}\text{of lysates from treated cells}\times 100]/P_{50}\text{of lysates from untreated cells}$$

^d

Antisickling studies with SS cells (20% hematocrit) were conducted under hypoxia (4% oxygen/96% nitrogen). Inhibition of sickling (%) was determined as

$$[\%\text{sickled cells from untreated sample}-\%\text{sickled cells from treated sample}\times 100]/\%\text{sickled cells from untreated sample}$$