Über einige Oxydationsprodukte der Tokopherole und analoger einfacher Modellkörper. 6. Mitteilung über Antisterilitätsfaktoren (Vitamin E)

John, W.; Dietzel, E.; Emte, W.

doi:10.1515/bchm2.1939.257.5-6.173

Cited by 69 publications

(7 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…60-68°) melted at 106-109°. Even though the melting point was low, the substance did not depress the melting point (113-114°) of a sample prepared by the reductive acetylation of the quinone (9,10).…”

Section: Experimental2mentioning

confidence: 91%

See 1 more Smart Citation

THE CHEMISTRY OF VITAMIN E. XXVII.¹ OXIDATION OF HYDROQUINONES, p-HYDROXYCHROMANS AND p-HYDROXYCOUMARANS TO QUINONES WITH CERIC SULFATE

Smith¹,

Ruoff²,

Wawzonek³

1941

J. Org. Chem.

View full text Add to dashboard Cite

Section: Experimental2mentioning

confidence: 91%

“…gave a solid melting at 45-46°, which soon liquefied upon standing at room temperature. John (9) reports the melting point 62°. Anal. Calc'd for CuH20O8: C, 71.19; H, 8.47.…”

Section: Experimental2mentioning

confidence: 99%

THE CHEMISTRY OF VITAMIN E. XXVII.¹ OXIDATION OF HYDROQUINONES, p-HYDROXYCHROMANS AND p-HYDROXYCOUMARANS TO QUINONES WITH CERIC SULFATE

Smith¹,

Ruoff²,

Wawzonek³

1941

J. Org. Chem.

View full text Add to dashboard Cite

“…α-TQ and γ-TQ were synthesized by oxidation with FeCl 3 or AuCl 3 from parent tocopherols as previously described (4). δ-TQ was synthesized by a modification of the general AgNO 3 oxidation procedure for tocopherols (12). δ-T, 130 mg, and 920 mg of AgNO 3 were dissolved in 6 mL of ethanol/water (85:15, vol/vol), heated at 60-70°C for 30 min, and the products extracted with diethyl ether.…”

Section: Methodsmentioning

confidence: 99%

Cytotoxicity of tocopherols and their quinones in drug‐sensitive and multidrug‐resistant leukemia cells

Cornwell

Jones

Jiang

et al. 1998

Lipids

View full text Add to dashboard Cite

Cytotoxicities of tocopherols (alpha-T, gamma-T, delta-t), their para (alpha-TQ, gamma-TQ, delta-TQ)- and ortho (Tocored)-quinone oxidation products, the synthetic quinone analog of gamma-TQ containing a methyl group substituted for the phytyl side-chain (TMCQ) and the synthetic quinone analog of Tocored containing a methyl group substituted for the phytyl side-chain (PR) were measured in acute lymphoblastic leukemia cell lines that are drug-sensitive (CEM) and multidrug-resistant (CEM/VLB100). Among tocopherols, only delta-T exhibited cytotoxicity. Among para quinones, alpha-TQ showed no cytotoxicity, while gamma-TQ and delta-TQ were highly cytotoxic in both CEM and CEM/VLB100 cell lines (LD50 < 10 muM). delta-TQ and gamma-TQ were more cytotoxic than the widely studied chemotherapeutic agent doxorubicin, which also showed selective cytotoxicity to CEM cells. The orthoquinone Tocored was less cytotoxic than doxorubicin in drug-sensitive cells but more cytotoxic than doxorubicin in multidrug-resistant cells. Cytotoxicity was not a function of the phytyl side-chain since both TMCQ and PR were cytotoxic in leukemia cells. Cytotoxic para and ortho quinones were electrophiles that formed adducts with nucleophilic thiol groups in glutathione and 2-mercaptoethanol. Cytotoxicity was enhanced when the glutathione pool was depleted by preincubation with buthionine-[S,R]-sulfoximine, but cytotoxicity was diminished by the addition of N-acetylcysteine to cultures. alpha-T also diminished the cytotoxicity of para- and orthoquinones. Buthionine-[S,R]-sulfoximine did not block the inhibitory effect of either N-acetylcysteine or alpha-T, showing that these agents did not act solely by maintaining the glutathione pool as an essential antioxidant system. In conclusion, tocopherylquinones represent a new class of alkylating electrophilic quinones that function as highly cytotoxic agents and escape multidrug resistance in acute lymphoblastic leukemia cell lines.

show abstract

“…Ten bands were observed with R f values from 0.01 to 0.85. As all products were oily and complete removal of solvent from them could not be guaranteed, their yields were calculated using known molar extinction coefficients in ethanol, which were as follows (in units of LM -1 cm -1 ): for c-tocopheryl quinone (3) at 262 nm, 19,000 (assumed similar to a-tocopheryl quinone) [4], for tocored (8) at 281 nm (270 nm in hexane [5]) (6,500) [6], for 2,2,7,8-tetramethylchroman-5,6-dione, the model compound of 8, at 467 nm (438 nm in hexane [5]), 1,200 [7], for 5-(c-tocopheryl)-c-tocopherol (10) (R f 0.48) at 300 nm 10,300 [6], and for its isomer (5) (R f 0.69) at 300 nm 10,500 [6]. The extinction coefficient of 1 at 298 nm, 3,802 [8], was also used to estimate 5-chloro-c-tocopherol (4) and the two chlorodimers, (13 and 14; bands 9 and 10).…”

Section: Oxidation Reactionmentioning

confidence: 99%

Reaction of γ‐Tocopherol with Hypochlorous Acid

Nguyen

Southwell-Keely

2007

Lipids

View full text Add to dashboard Cite

In addition to being a very good antioxidant, gamma-tocopherol is also an excellent electrophile trap. This is a study of the reactivity of gamma-tocopherol with hypochlorous acid/hypochlorite, a potential biological foe that is both an oxidant and an electrophile. Aqueous sodium hypochlorite (1.72 mmol; pH 7.4) was stirred with gamma-tocopherol (0.12 mmol) in hexane for 2 min at room temperature. The following products were isolated: gamma-tocopheryl quinone (0.6%), tocored (10%), 3-chloro-gamma-tocopheryl quinone (14%), an ether dimer of 3-chloro-gamma-tocopheryl quinone (0.4%), two isomers of 5-(5-gamma-tocopheryl)-gamma-tocopherol (3 and 2% respectively), 5-chloro-gamma-tocopherol (14%) and two chlorinated dimers (14 and 24% respectively) which were identified as diastereomers of (3R,10R)-11a-chloro-2,3,9,10-tetrahydro-3,5,6,10,12,13-hexamethyl-3,10-bis[(4R,8R)-4,8,12-trimethyltridecyl]-1H-pyrano(3,2a)-8H-pyrano(3,2g)-dibenzofuran-14(7aH)(14aH)-one. The chlorinated dimers, 5-chloro-gamma-tocopherol, 3-chloro-gamma-tocopheryl quinone and its ether dimer are new compounds.

show abstract

Über einige Oxydationsprodukte der Tokopherole und analoger einfacher Modellkörper. 6. Mitteilung über Antisterilitätsfaktoren (Vitamin E)

Cited by 69 publications

References 7 publications

THE CHEMISTRY OF VITAMIN E. XXVII.¹ OXIDATION OF HYDROQUINONES, p-HYDROXYCHROMANS AND p-HYDROXYCOUMARANS TO QUINONES WITH CERIC SULFATE

THE CHEMISTRY OF VITAMIN E. XXVII.¹ OXIDATION OF HYDROQUINONES, p-HYDROXYCHROMANS AND p-HYDROXYCOUMARANS TO QUINONES WITH CERIC SULFATE

Cytotoxicity of tocopherols and their quinones in drug‐sensitive and multidrug‐resistant leukemia cells

Reaction of γ‐Tocopherol with Hypochlorous Acid

Contact Info

Product

Resources

About

Über einige Oxydationsprodukte der Tokopherole und analoger einfacher Modellkörper. 6. Mitteilung über Antisterilitätsfaktoren (Vitamin E)

Cited by 69 publications

References 7 publications

THE CHEMISTRY OF VITAMIN E. XXVII.1 OXIDATION OF HYDROQUINONES, p-HYDROXYCHROMANS AND p-HYDROXYCOUMARANS TO QUINONES WITH CERIC SULFATE

THE CHEMISTRY OF VITAMIN E. XXVII.1 OXIDATION OF HYDROQUINONES, p-HYDROXYCHROMANS AND p-HYDROXYCOUMARANS TO QUINONES WITH CERIC SULFATE

Cytotoxicity of tocopherols and their quinones in drug‐sensitive and multidrug‐resistant leukemia cells

Reaction of γ‐Tocopherol with Hypochlorous Acid

Contact Info

Product

Resources

About

THE CHEMISTRY OF VITAMIN E. XXVII.¹ OXIDATION OF HYDROQUINONES, p-HYDROXYCHROMANS AND p-HYDROXYCOUMARANS TO QUINONES WITH CERIC SULFATE

THE CHEMISTRY OF VITAMIN E. XXVII.¹ OXIDATION OF HYDROQUINONES, p-HYDROXYCHROMANS AND p-HYDROXYCOUMARANS TO QUINONES WITH CERIC SULFATE