L-Tryptophan-13C11,15N2 (Tryptophan-13C11,15N2) is the 13C- and 15N-labeled L-Tryptophan. L-Tryptophan (Tryptophan) is an essential amino acid that is the precursor of serotonin, melatonin, and vitamin B3.

3-Oxo-7-hydroxychol-4-enoic acid is an endogenous metabolite. 3-Oxo-7-hydroxychol-4-enoic acid may be an important indicator of a poor prognosis in hepatobiliary disease.

Delta-12-Prostaglandin J2 (Δ12-PGJ2) is a cyclopentenone prostaglandin (PG) with anti-proliferative effect on various tumor cell growth. Delta-12-Prostaglandin J2, a naturally occurring dehydration product of prostaglandin D2, is able to induce apoptosis in HeLa cells via caspase activation.

C20 Ceramide is a natural 20:0 ceramide that is abundant in the brain.

ω-Muricholic acid (ω-MCA) is a murine-specific secondary bile acid.

p-Cresyl Sulfate, a major uremic toxin derived from the metabolites of tyrosine and phenylalanine through liver, existed in the blood of patients with chronic kidney disease (CKD).

Pregnanediol 3-glucuronide is the major terminal metabolite of progesterone, playing an important role in physiological processes, such as the female menstrual cycle, pregnancy (supports gestation), embryogenesis and maternal immune response of humans and other species.

12-OxoETE induces a rapid, dose dependent increase of cytoplasmic free calcium via leukotriene B4 receptor or a common activation sequence.

Protectin D1 (also known as neuroprotectin D1 when produced in neuronal tissues) is a DHA-derived dihydroxy fatty acid that exhibits potent protective and anti-inflammatory activities.

Dihomo-γ-Linolenic acid is an n-6 polyunsaturated fatty acid that is mainly metabolized to an anti-inflammatory eicosanoid, prostaglandin (PG) E1, via the cyclooxygenase (COX) pathway. Anti-inflammatory and anti-proliferative effects.

4β-hydroxy Cholesterol is a major oxysterol cholesterol metabolite and a precursor in the synthesis of bile acids that is found in human circulation.

1,7-Dimethyluric acid is the metabolite of caffeine.

AFMK, antioxidant metabolite of Melatonin, attenuates X-ray-induced oxidative damage to DNA, proteins and lipids in mice. AFMK is a poorer scavenger. The pKa of AFMK at physiological pH is 8.7. Antioxidant capacity. AFMK improves the anti-tumor effect of Gemcitabine in PANC-1 cells through the modulation of apoptotic pathway.

Lignoceric acid (Tetracosanoic acid) is a 24-carbon saturated (24:0) fatty acid, which is synthesized in the developing brain. Lignoceric acid is also a by-product of lignin production. Lignoceric acid can be used for Zellweger cerebro‐hepato‐renal syndrome and adrenoleukodystrophy research.

Sphinganine 1-phosphate (D-erythro-Dihydrosphingosine 1-phosphate) is a polar sphingolipid metabolite that regulates cell migration, differentiation, survival and complex physiological processes.

trans-urocanic acid (trans-UCA), a natural epidermal constituent, inhibits human natural killer cell (NK) activity in vitro. trans-urocanic acid is active in regulating an immune function.

Streptolysin O, a group A streptococcal toxin, is a well-characterized oxygen-labile prototype of a cholesterol-binding bacterial exotoxin. Streptolysin O causes both lysis of cells and cardiotoxicity. Streptolysin O is widely used for the controlled permeabilization of cell membranes. Streptolysin O exists in two forms, a reduced active state and an oxidized reversibly inactive state .

L-Methionine sulfoxide (H-Met(O)-OH), a metabolite of Methionine, induces M1/classical macrophage polarization, and modulates oxidative stress and purinergic signaling parameters.

Indole-3-acetaldehyde inhibits Escherichia coli O157:H7 biofilm formation.

4-Hydroxytryptamine creatinine sulfate, a tryptamine derivative, is a neurotransmitter agonist.

Phosphoribosyl pyrophosphate (PRPP) pentasodium is an important metabolite required in the biosynthesis of purine and pyrimidine nucleotides, the amino acids histidine and tryptophan, and the cofactors NAD and NADP.

Triiodothyronine sulfate is the main metabolite of thyroid hormone triiodothyronine (T3). Triiodothyronine is an active form of thyroid hormone, which binds to β1 thyroid hormone receptor (TRβ1), and activates its activity.

Deutarserine is a deuterium modified analog of endogenous D-serine (CTP 692), which is used in the research of adults with schizophrenia.

Larsucosterol sodium is a cholesterol metabolite from the nuclei of normal human liver tissues, epigenetically regulates the transcription of proteins and enzymes involved in lipid synthesis, inflammation, and apoptosis.

Larsucosterol is a cholesterol metabolite from the nuclei of normal human liver tissues, epigenetically regulates the transcription of proteins and enzymes involved in lipid synthesis, inflammation, and apoptosis.

Ebaresdax can inhibit peroxynitrite oxidation derived by SIN-1 and peroxynitrite mediated Cytotoxicity with IC50s of 3.7±0.80 and 0.13±0.02 uM, respectively.

3-Oxo-4,6-choladien-24-oic acid is an endogenous metabolite. 3-Oxo-4,6-choladien-24-oic acid exsists in the urine of patients with hepatobiliary disease.

2,8-Dihydroxyadenine, an endogenous metabolite, can cause the formation of urinary crystals and kidney stones. 2,8-Dihydroxyadenine can be used to diagnose adenine phosphoribosyltransferase (APRT) deficiency.

Folitixorin (5,10-methylenetetrahydrofolate) is a cofactor and an analog of leucovorin. Folitixorin is a promising agent for modulation of 5-FU cytotoxicity in adjuvant cancer research.

Angiotensinogen (1-14), human TFA is a fragment of the renin substrate angiotensinogen. Angiotensinogen is naturally occurring substrate for renin and a precursor for all angiotensin peptides.