Tacrolimus anhydrous 8-epimer is a new l-pipecolic acid macrolide lactone, an important immunosuppressive drug that blocks T cell proliferation in vitro by inhibiting the generation of several lymphokines, especially IL-2.
3-epi-25-hydroxy Vitamin D3is the C-3 epimer of 25-hydroxy vitamin D3.1Dietary administration of 3-epi-25-hydroxy vitamin D3(0.5 and 1 IU/g) decreases levels of serum parathyroid hormone (PTH) in male, but not female, weanling rats.
1.Djekic-Ivankovic, M., Lavery, P., Agellon, S., et al.The C-3α epimer of 25-hydroxycholecalciferol from endogenous and exogenous sources supports normal growth and bone mineral density in weanling ratsJ. Nutr.147(2)141-151(2017)
Resolvins are a family of potent lipid mediators derived from both eicosapentaenoic acid and docosahexaenoic acid.[1] In addition to being anti-inflammatory, resolvins promote the resolution of the inflammatory response back to a non-inflamed state.[2] Resolvin D1 is produced physiologically from the sequential oxygenation of DHA by 15- and 5-lipoxygenase.[1] 17(R)-RvD1 is an aspirin-triggered epimer of RvD1 that reduces human polymorphonuclear leukocyte (PMN) transendothelial migration, the earliest event in acute inflammation, with equipotency to RvD1 (EC50 = ~30 nM).[3] 17(R)-RvD1 exhibits a dose-dependent reduction in leukocyte infiltration in a mouse model of peritonitis with maximal inhibition of ~35% at a 100 ng dose.[3] In contrast to RvD1, the aspirin-triggered form resists rapid inactivation by eicosanoid oxidoreductases. Analytical and biological comparisons of synthetic 17(R)-RvD1 with endogenously derived 17(R)-RvD1 have confirmed its identity as matching the natural product.[4]
17(R)-Protectin D1 is an aspirin-triggered epimer of the specialized pro-resolving mediator protectin D1 .1It decreases leukotriene B4-induced transendothelial migration of human polymorphonuclear (PMN) neutrophils when used at concentrations ranging from 0.1 to 10 nM. 17(R)-Protectin D1 (0.01-10 ng) reduces the recruitment of neutrophils in a mouse model of TNF-α-induced peritonitis.
1.Serhan, C.N., Fredman, G., Yang, R., et al.Novel proresolving aspirin-triggered DHA pathwayChem. Biol.18(18)976-987(2011)
11β-PGE2 is the C-11 epimer of PGE2. It is a moderate inhibitor of PGE2 binding to rat hypothalamic membranes with a Ki value of 53 nM.[1] 11β-PGE2 also stimulates bone resorption in rats at concentrations of 10-8 to 10-6 M which is similar to PGE2.2 11β-PGE2 inhibits PGE2 binding to the prostaglandin transporter protein with a Ki of 56 nM.[3]
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15(R)-Pinane thromboxane A2 is the (R)-epimer of pinane thromboxane A2 . 15(R)-PTA2 does not inhibit collagen-induced platelet aggregation (IC50s = 120-130 μM). It does not affect gastric tone in isolated rat gastric fundus when used at concentrations of 0.5 or 1.5 μg/ml and is less effective than PTA2 at inhibiting prostaglandin-induced contraction of isolated rat stomach muscle.
Chlortetracycline is an analog of tetracycline , a broad spectrum antibiotic. In addition to its actions against microorganisms, chlortetracycline suppresses inflammation by inhibiting neutrophil action and other aspects of the innate immune response. 4-epi-Chlortetracycline is an epimer of chlortetracycline.
5(S),12(S)-DiHETE is a natural bioactive lipid derived from arachidonic acid . It is synthesized by glycogen-induced rabbit peritoneal polymorphonuclear leukocytes (PMNLs) incubated with AA. 5(S),12(S)-DiHETE can be produced by successive oxygenation of AA by 5-lipoxygenase (5-LO) in platelets and 12-LO in leukocytes. It can also be synthesized from 12(S)-HETE by 5-LO, in the presence of 5-LO activating protein (FLAP), activated with calcium ionophore. 5(S),12(S)-DiHETE is an epimer of leukotriene B4 that is weakly chemotactic for PMNL.
Epitetracycline is an epimer of the antibiotic tetracycline . Epimers of tetracycline form without catalysis and are considered degradation products. Epitetracycline has decreased activity as an antibiotic or a Tet repressor effector but may have stronger toxic effects in animals.