Reference

Potentiated susceptibility of ascites tumor to acyl derivatives of ascorbate caused by balanced hydrophobicity in the molecule

Potentiated susceptibility of ascites tumor to acyl derivatives of ascorbate caused by balanced hydrophobicity in the molecule. Miwa, N.; Yamazaki, H. (Dep. Antibiot., Natl. Inst. Health, Tokyo, Japan). Exp. Cell Biol., 54(5), 245-9 (English) 1986. CODEN: ECEBDI. ISSN: 0304-3568. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Section cross-reference(s): 18 The order of susceptibility of Ehrlich ascites tumor to L-ascorbic acid (Asc) [50-81-7] and its 6-stearoyl (6S) [10605-09-1], 6-palmitoyl (6P) [137-66-6] and 2,6-dipalmitoyl (DP) [4218-81-9] derivs. in vitro and in vivo was 6P (a 50% growth inhibitory concn. (IC50) for cultured cells, 12 mM; an increased life-span of treated mice, 283%) > 6S (61 mM; 240%) ? Asc (430 mM; 122%) 3DP (>200 mM; 89%). This indicated that the enhanced susceptibility was due to the acyl moiety substituted at the C6-hydroxyl group of Asc, but was retracted by further substitution at the C2-hydroxyl group. Equimolar mixt. of Asc and palmitic acid, stearic acid, or their Me esters was much less cytotoxic than 6P or 6S. Thus, the enhanced susceptibility was not primarily due to an additive cytotoxic effect of ascorbyl and acyl moieties, but to a balanced hydrophobicity introduced into the mol. by a poorly cytotoxic acyl moiety.

A new efficacy test of antioxidants based on air-oxidation of linoleic acid

A new efficacy test of antioxidants based on air-oxidation of linoleic acid. Tanizawa, Hisayuki; Sazuka, Yasuyuki; Komatsu, Akiko; Toda, Shizuo; Takino, Yoshio (Shizuoka Coll. Pharm., Shizuoka 422, Japan). 50-81-7 and 10605-09-1 are also occured in this study. Chem. Pharm. Bull., 31(11), 4139-43 (English) 1983. CODEN: CPBTAL. ISSN: 0009-2363. DOCUMENT TYPE: Journal CA Section: 17 (Food and Feed Chemistry) Though many methods are available for the efficacy testing of antioxidants, a satisfactory method has not been established yet, because the conventional methods require a long exptl. time, considerable tech. skill, or large and expensive app. A new method based on the air-oxidn. of linoleic acid [60-33-3] by air bubbling (2 h incubation at 60° with 500 mL/min air flow rate) was established. Good reproducibility and low variation were obtained by this method. Six tested antioxidants (ascorbic acid [50-81-7], ascorbyl stearate [10605-09-1], BHA [25013-16-5], BHT [128-37-0], propyl gallate [121-79-9], a-tocopherol [59-02-9]) inhibited the oxidn. of linoleic acid proportionally to their added concn. The relative efficacies of the 6 antioxidants were in broad agreement with the expected. .