The phosphatidylinositol (PtdIns) phosphates represent a small percentage of total membrane phospholipids. However, they play a critical role in the generation and transmission of cellular signals. PtdIns-(1,2-dioctanoyl) is a synthetic analog of natural phosphatidylinositol (PtdIns) containing C8:0 fatty acids at the sn-1 and sn-2 positions. The compound features the same inositol and diacyl glycerol (DAG) stereochemistry as that of the natural compound. The short fatty acid chains of this analog, compared to naturally-occurring PtdIns, gives it different physical properties including high solubility in aqueous media. PtdIns are phosphorylated to mono- (PtdIns-P; PIP), di- (PtdIns-P2; PIP2), and triphosphates (PtdIns-P3; PIP3). Hydrolysis of PtdIns-(4,5)-P2 by phosphoinositide (PI)-specific phospholipase C generates inositol triphosphate (IP3) and DAG which are key second messengers in an intricate biochemical signal transduction cascade.
Pyrindolol is a bacterial metabolite that has been found inS. alboverticillatus.1It inhibits neutral β-galactosidase by 50% under acidic, but not neutral, conditions when used at a concentration of 2 μg ml. It is selective for β-galactosidase isolated from bovine liver over β-galactosidases isolated from human, bovine, pig, and rat tissues and sialidases isolated fromC. perfringens,Streptomyces, and the H3N2 strain of influenza virus (IC50s = >250 μg ml for all).1,2 1.Aoyagi, T., Kumagai, M., Hazato, T., et al.Pyridindolol, a new β-galactosidase inhibitor produced by actinomycetesJ. Antibiot. (Tokyo)28(7)555-557(1975) 2.Kumagai, M., Aoyagi, T., and Umezawa, H.Inhibitory activity of pyridindolol on β-galactosidaseJ. Antibiot. (Tokyo)29(7)696-703(1976)
FKGK 18 is an inhibitor of group VIA (GVIA) calcium-independent phospholipase A2 (iPLA2). It inhibits GVIA iPLA2 by 99.9% at 0.091 mole fraction in a mixed micelle activity assay and is selective for GVIA iPLA2 over GIVA cPLA2 and GV sPLA2 where it shows 80.8 and 36.8% inhibition, respectively. FKGK 18 inhibits iPLA2β activity in cytosolic extracts from INS-1 cells overexpressing iPLA2β (IC50 = ~50 nM) as well as iPLA2γ activity in mouse heart membrane fractions (IC50s = ~1-3 μM). It inhibits glucose-induced increases in prostaglandin E2 production and insulin secretion in human pancreatic islets when used at a concentration of 10 μM and inhibits thapsigargin-induced apoptosis in INS-1 cells overexpressing iPLA2β in a concentration-dependent manner. FKGK 18 (20 mg/kg, 3 times per week) reduces blood glucose levels in an intraperitoneal glucose tolerance test, decreases the incidence of diabetes, and increases serum insulin levels in non-obese diabetic (NOD) mice.
D-myo-Inositol-1,3-phosphate (Ins(1,3)P) is a member of the inositol phosphate (InsP) molecular family that play critical roles as small, soluble second messengers in the transmission of cellular signals. The most studied InsP, Ins(1,4,5)P3 is a second messenger produced in cells by phospholipase C (PLC)-mediated hydrolysis of phosphatidylinositol-4,5-biphosphate. Binding of Ins(1,4,5)P3 to its receptor on the endoplasmic reticulum results in opening of the calcium channels and an increase in intracellular calcium. Ins(1,3)P2 can be dephosphorylated to Ins(1)P by inositol polyphosphate 3-phosphatase and further dephosphorylated to inositol by inositol monophosphatase.
C24 dihydro Ceramide is a sphingolipid that has been found in the stratum corneum of human skin.[1] It is found in higher concentrations in female sebum compared to male sebum.[2] C24 dihydro Ceramide levels positively correlate with cytotoxicity in CCRF-CEM, MOLT-4, COG-LL-317h, and COG-LL-332h T cell acute lymphoblastic leukemia (ALL) cell lines.[4] Levels of C24 dihydro ceramide are increased by 149.49-fold in dihydroceramide desaturase 1 (DEGS1) knockdown UM-SCC-22A human head and neck squamous carcinoma cells in vitro.[4] C24 dihydro Ceramide levels are also increased in INS-1 β-cells incubated with glucose and palmitate.[5]
D-myo-Inositol-4-phosphate (Ins(4)P1) is a member of the inositol phosphate (InsP) molecular family that play critical roles as small, soluble second messengers in the transmission of cellular signals. The most studied InsP, Ins(1,4,5)P3, is a second messenger produced in cells by phospholipase C (PLC)-mediated hydrolysis of phosphatidylinositol-4,5-diphosphate. Binding of Ins(1,4,5)P3 to its receptor on the endoplasmic reticulum results in opening of the calcium channels and an increase in intracellular calcium. Ins(4)P1 can be formed by dephosphorylation of Ins(1,4)P2 by inositol polyphosphate 1-phosphatase or dephosphorylated to inositol by inositol monophosphatase.
Oasomycin B is a bacterial metabolite that has been found inS. baldaciiand has antiprotozoal activity.1It is active againstT. vaginalis(MIC = 62.5 μg/ml). 1.Grabley, S., Kretzschmar, G., Mayer, M., et al.Secondary metabolites by chemical screening, 24. Oasomycins, new macrolactones of the desertomycin familyLiebigs Ann. Chem.5573-589(1993)
N-Arachidonoyl taurine is an arachidonoyl amino acid. It is oxygenated by 12(S)- and 15(S)-lipoxygenase and is converted to 12-HETE-taurine (12-HETE-T) in murine resident peritoneal macrophages. N-Arachidonoyl taurine is an activator of the transient receptor potential vanilloid (TRPV) channels TRPV1 and TRPV4 (EC50s = 28 and 21 μM, respectively). It increases calcium flux in HIT-T15 pancreatic β-cells and INS-1 rat islet cells when used at a concentration of 10 μM and increases insulin secretion from 832 13 INS-1 pancreatic β-cells. The levels of N-arachidonoyl taurine are changed in mouse brain following administration of δ9-tetrahydrocannabinol (δ9-THC).