- Switching Lysophosphatidylserine G Protein-Coupled Receptor Agonists to Antagonists by Acylation of the Hydrophilic Serine Amine
-
Three human G protein-coupled receptors (GPCRs)—GPR34/LPS1, P2Y10/LPS2, and GPR174/LPS3—are activated specifically by lysophosphatidylserine (LysoPS), an endogenous hydrolysis product of a cell membrane component, phosphatidylserine (PS). LysoPS consists of-serine, glycerol, and fatty acid moieties connected by phosphodiester and ester linkages. We previously generated potent and selective GPCR agonists by modification of the three modules and the ester linkage. Here, we show that a novel modification of the hydrophilic serine moiety, that is, N-acylations of the serine amine, converted a GPR174 agonist to potent GPR174 antagonists. Structural exploration of the amide functionality provided access to a range of activities from agonist to partial agonist to antagonist. The present study would provide a new strategy for the development of lysophospholipid receptor antagonists.
- Sayama, Misa,Uwamizu, Akiharu,Ikubo, Masaya,Chen, Luying,Yan, Ge,Otani, Yuko,Inoue, Asuka,Aoki, Junken,Ohwada, Tomohiko
-
p. 10059 - 10101
(2021/07/28)
-
- Reactivity of α-Amino Acids in the Reaction with Esters in Aqueous–1,4-Dioxane Media
-
The kinetics of the reaction of a series of α-amino acids with 4-nitrophenyl acetate, 4-nitrophenyl benzoate, and 2,4,6-trinitrophenyl benzoate in aqueous 1,4-dioxane medium has been studied. Kinetics of the reactions involving 4-nitrophenyl acetate and 2,4,6-trinitrophenyl benzoate has complied with the Br?nsted dependence and revealed linear correlation between rate constant logarithm and the energy difference of the frontier orbitals of α-amino acids anions.
- Kochetova,Kustova,Kuritsyn
-
-
- Peptide Tyrosinase Activators
-
Peptides that increase melanin synthesis are provided. These peptides include pentapeptides YSSWY, YRSRK, and their variants. The peptides may activate the enzymatic activity of tyrosinase to increase melanin synthesis. The pharmaceutical, cosmetic, and other compositions including the peptides are also provided. The methods of increasing melanin production in epidermis of a subject are provided where the methods include administering compositions comprising an amount of one or more peptides effective to increase the melanin production. The methods also include treating vitiligo or other hypopigmentation disorders with compositions including one or more peptides.
- -
-
-
- Improved synthesis of d-allothreonine derivatives from l-threonine
-
The improved synthesis of protected d-allothreonine derivatives [Fmoc-d-alloThr(tBu)-OH (1) and Fmoc-d-alloThr-OtBu (2)] is described. The epimerization of cheap l-threonine (l-Thr) (3) with catalytic salicylaldehyde afforded a mixture of l-Thr (3) and d-alloThr (4) and separation of ammonium salt gave d-alloThr (4) in 96% de. The chemoselective deprotection of tert-butyl ether or tert-butyl ester of Fmoc-d-alloThr(tBu)-O tBu (5) easily succeeded in converting Fmoc-d-alloThr( tBu)-OH (1) or Fmoc-d-alloThr-OtBu (2), respectively.
- Kikuchi, Mari,Konno, Hiroyuki
-
p. 7098 - 7101
(2013/07/26)
-
- Preparation of optically active allothreonine by separating from a diastereoisomeric mixture with threonine
-
A simple procedure is described to obtain D-and L-allothreonine (D-and L-aThr). A mixture of N-acetyl-D-allothreonine (Ac-D-aThr) and N-acetyl-L-threonine (Ac-L-Thr) was converted to a mixture of their ammonium salts and then treated with ethanol to precipitate ammonium N-acetyl-L- threoninate (Ac-L-Thr.NH3) as the less-soluble diastereoisomeric salt. After separating Ac-L-Thr.NH3 by filtration, Ac-D-aThr obtained from the filtrate was hydrolyzed in hydrochloric acid to give D-aThr of 80% de, recrystallized from water to give D-aThr of >99% de. L-aThr was obtained from a mixture of the ammonium salts of Ac-L-aThr and Ac-D-Thr in a similar manner.
- Yajima, Tatsuo,Ichimura, Serina,Horii, Shirabe,Shiraiwa, Tadashi
-
body text
p. 2106 - 2109
(2011/06/25)
-
- Structure elucidation of Sch 20562, a glucosidic cyclic dehydropeptide lactone: The major component of W-10 antifungal antibiotic
-
A novel bacterium designated as Aeromonas sp. W-10 produces the antibiotic W-10 complex which comprises of two major and several minor components. The two major components from this complex, Sch 20562 (1) and Sch 20561 (1a), are of biological interest in view of their potent antifungal activity. The chemical degradation studies utilized for the assignment of structure 1 for Sch 20562 are described here. Some of the noteworthy diversity of structural features in this glucosidic cyclic dehydrononapeptide lactone 1 are: an N-terminal (D)-β-hydroxymyristyl unit, three D-amino acid units, two (E)-α-aminocrotonyl units, and an O-α-D-glucosyl-N-methyl-L-allo-threonine unit. The structure determination of 1 utilized the selective cleavage of the dehydropeptide units by ozonolysis to form fragments that were sequenced by mass spectrometry. The stereochemistry of the amino acid units were assigned by isolation of the free amino acids from the hydrolysates of the fragments. The stereochemistry of the α-aminocrotonyl units and the glucosidic linkage were assigned by nmr spectroscopy and molecular rotation data.
- Afonso, Adriano,Hon, Frank,Brambilla, Ray
-
p. 383 - 397
(2007/10/03)
-
- Synthetic studies on threonines. The preparation of protected derivatives of D-allo- and L-allo-threonine for peptide synthesis
-
N-Acetylated threonine derivatives, having tert-butyl or benzyl-based side-chain protection, form isolable 5(4H)-oxazalones on treatment with N-ethyl-N'-3-dimethylaminopropyl carbodiimide. N-chloroacetylated threonine derivatives, on the other hand, do not form oxazolones so readily. The N-acetylated oxazolones an easily epimerized and lead to diastereoisomeric mixtures of threonine derivatives on hydrolysis with dilute aqueous acid. The components of these mixtures can be separated chromatogaphically, but a useful alternative for the O-benzylated mixture is selective enzymatic hydrolysis using hog kidney acylase. These chemical transformations provide the basis for practical syntheses of protected derivatives of the non-proteinogenic allo-threonines, suitable for use in peptide synthesis.
- Lloyd-Williams, Paul,Sanchez, Agusti,Carulla, Natalia,Ochoa, Teresa,Giralt, Ernest
-
p. 3369 - 3382
(2007/10/03)
-
- Cosmetic composition
-
A composition suitable for topical application to mammalian skin and hair for inducing, maintaining or increasing hair growth comprises a hair growth promoter chosen from glutamine derivatives and salts thereof. The composition preferably also comprises an activity enhancer which may be chosen from hair growth stimulants, penetration enhancers and cationic polymers.
- -
-
-
- Cosmetic composition containing DOPA derivatives
-
A composition for topical application to human hair or skin contains a chemical analogue of dihydroxyphenyl alanine (DOPA). This chemical analogue can be absorbed by skin or by a hair follicle and metabolised in-vivo, thus leading to the formation of melanin in skin or to the growth of melanin-pigmented hair. Consequently the composition can give controlled skin darkening to mimic sun-induced tanning or can bring about the growth of dar hair in place of the grey or white hair.
- -
-
-
- Cosmestic composition
-
A composition suitable for topical application to mammalian skin and hair for inducing, maintaining or increasing hair growth comprises a hair growth promoter chosen from glutamic acid derivatives and salts thereof. The composition preferably also comprises an activity enhancer which may be chosen from hair growth stimulants, penetration enhancers and cationic polymers.
- -
-
-
- Hair growth composition containing citric acid esters
-
Triesters of citric acid are used for inducing, maintaining or increasing hair growth. Compositions for topical application to mammalian hair or scalp comprise an effective amount of from 1% to 99% by weight of an ester of citric acid having the structure (1): where, R1, R2 and R3 each independently represent a branched or unbranched alkyl, alkenyl, aryl, alkylaryl or arylalkyl group, each said group having from 1 to 18 carbon atoms, R4 represents -H, or a branched or unbranched saturated or unsaturated acyl, alkyl, aryl, alkylaryl or aylalkyl group having from 1 to 18 carbon atoms, in the presence of a cosmetically acceptable vehicle for the citric acid ester and in the absence of solid absorbent for the ester;, said effective amount of said ester being sufficient to increase hair growth in the rat, when said composition is applied topically thereto over a period of no more than three months, by at least 10% more than that obtainable using a control composition from which the said ester has been omitted, in accordance with the Rat Hair Growth Test.
- -
-
-
- Cosmetic composition
-
A composition suitable for topical application to mammalian skin and hair for inducing, maintaining or increasing hair growth comprises a hair growth promoter chosen from N-acylated amino-acids, in which the acyl group has from 2 to 20 carbon atoms, together with a cosmetically acceptable vehicle for the hair growth promoter.
- -
-
-