Analysis of Citrus Bioflavonoid Content and Dipeptidyl Peptidase-4 Inhibitory Potential of Commercially Available Supplements

Citrus bioflavonoids are polyphenolic plant-derived pigments found in high levels in oranges, lemons, grapefruits and other citrus fruits. The three most abundant types of citrus bioflavonoids are hesperidin, naringenin and eriocitrin. Citrus bioflavonoids have long been known to possess powerful free radical-scavenging properties and cardioprotective effects. The study involved the analysis of 10 commercially available citrus bioflavonoid supplements from three different countries: Australia, the United States and Canada. The supplements were tested for their citrus bioflavonoid content which varied from 0.8 to 33.3% w/w. The daily bioflavonoid dose varied from 19 mg to 560 mg. Hesperidin was the major citrus bioflavonoid in nine out of ten supplements. One supplement was found to contain less than 10% of the quantity of rutin claimed to have been added. The DPP-4 inhibitory potential, compared through an estimation of rutin equivalence, ranged from 1.9 mg to 400 mg per day. This data highlights the variability between the supplements in their potential to inhibit DPP-4 for subsequent health benefits.     

Synthesis,Spectroscopic Characterization,DFT Calculations,and Dynamic Behavior of Mononuclear Macrocyclic Diorganotin(IV) Bis‐Dithiocarbamate Complexes

Nine mononuclear diorganotin(IV) dithiocarbamate complexes 1 – 9 with 19‐, 20‐ and 21‐membered macrocyclic structures were synthesized from dimethyl, di‐n‐butyl, and diphenyltin(IV) dichloride and three bis‐dithiocarbamate ligands derived from secondary bis‐amines having aromatic spacer groups. All compounds were characterized by elemental analysis, mass spectrometry, and spectroscopic methods (IR and ¹H, ¹³C, and ¹¹⁹Sn NMR). Additionally, quantum chemical DFT calculations were performed for the dimethyltin(IV) derivatives in order to model the molecular structures. For one compound series the NMR spectra showed a concentration‐dependent behavior in solution, which was analyzed in detail and permitted to postulate the existence of an equilibrium with the corresponding [2+2] macrocycles.     

Synthese und Charakterisierung donor-funktionalisierter ansa-Metallocene von Yttrium,Neodym, Samarium,Erbium und Lutetium

Organometallic Compounds of the Lanthanides. 133 Synthesis and Characterization of donor-functionalised ansa -Metallocenes of Yttrium, Neodymium, Samarium, Erbium, and Lutetium The reaction of Me₂SiCl₂ with K[C₅H₄^tBu], Li[C₅H₄SiMe₃] or K[C₅H₃^tBuMe-3] followed by treatment with K[C₅H₄CH₂CH₂NMe₂] yields mixed substituted dicyclopentadienyldimethylsilanes which after double deprotonation with KH afford the dipotassium salts K₂[Me₂Si(C₅H₃^tBu-3)(C₅H₃CH₂CH₂NMe₂-3)] ( 1 ), K₂[Me₂Si · (C₅H₃SiMe₃-3)(C₅H₃CH₂CH₂NMe₂-3)] ( 2 ), and K₂[Me₂Si · (C₅H₂^tBu-3-Me-5)(C₅H₃CH₂CH₂NMe₂-3)] ( 3 ), respectively. The reaction of 1 , 2 , or 3 with LnCl₃(THF)_x (Ln = Y, La, Nd, Sm, Er, Lu) leads to the complexes [Me₂Si(C₅H₃^tBu-3) · (C₅H₃CH₂CH₂NMe₂-3)]LnCl [Ln = Y ( 4 a ), Sm ( 4 c ), Lu ( 4 e )], [Me₂Si(C₅H₃SiMe₃-3)(C₅H₃CH₂CH₂NMe₂-3)]LnCl [Ln = Y ( 5 a ), Sm ( 5 c ), Lu ( 5 e )], and [Me₂Si(C₅H₂^tBu-3-Me-5)(C₅H₃CH₂CH₂NMe₂-3)]LnCl [Ln = Y ( 6 a ), Nd ( 6 b ), Sm ( 6 c ), Er ( 6 d ), Lu ( 6 e )], respectively. Alkylation of 4 a , 4 c , 5 a , and 6 b , 6 e with LiCH₃, LiCH₂SiMe₃, and LiCH(SiMe₃)₂ produces the alkylmetallocenes [Me₂Si(C₅H₃^tBu-3) · (C₅H₃CH₂CH₂NMe₂-3)]LnR [R = CH₃, Ln = Y ( 7 a ), Sm ( 7 c ); R = CH₂SiMe₃, Ln = Y ( 8 a )], [Me₂Si(C₅H₃SiMe₃-3) · (C₅H₃CH₂CH₂NMe₂-3)]YCH₃ ( 9 a ), and [Me₂Si(C₅H₂^tBu3-Me-5)(C₅H₃CH₂CH₂NMe₂-3)]LnR (R = CH₃, Ln = Lu ( 10 e ); R = CH₂SiMe₃, Ln = Lu ( 11 e ); R = CH(SiMe₃)₂, Ln = Nd ( 12 b ), Lu ( 12 e )], respectively. All new compounds were characterized by elemental analyses, NMR spectroscopy and mass spectrometry. The molecular structure of 6 c and 6 e was determined by single crystal X-ray structure analysis.     

Die Kristallstruktur von TlFeSe2 und TlFeS2

TlFeSe₂ is monoclinic, space groupC2/m–C _2h ³ ,a=11.973 Å,b=5.490 Å,c=7.110 Å, =118.2°,Z=4.TlFeS₂ is isotypic witha=11.636 Å,b=5.304 Å,c=6.799 Å, =116.7°.The crystal structure of TlFeSe₂ has been determined from single crystal diffractometer data. Isotypy of the sulfide has been confirmed from powder diffraction data. The crystal structure containing infinite linear chains of edgesharing FeX ₄-tetrahedra, and its relationship to the thio- and selenoferrates of the alkali metals are discussed. The mineral raguinite is very probably isotypic to synthetic TlFeS₂.

     

Synthesis and Characterization of β‐Diketiminate Aluminum Compounds and Their Use in the Ring‐Opening Polymerization of ε‐Caprolactone

Four aluminum alkyl compounds, [CH{(CH₃)CN‐2,4,6‐MeC₆H₂}₂AlMe₂] ( 1 ), [CH{(CH₃)CN‐2,4,6‐MeC₆H₂}₂AlEt₂] ( 2 ), [CH{(CH₃)CN‐2‐iPrC₆H₄}₂AlMe₂] ( 3 ), and [CH{(CH₃)CN‐2‐iPrC₆H₄}₂AlEt₂] ( 4 ), bearing β‐diketiminate ligands [CH{(Me)CN‐2,4,6‐MeC₆H₂}]₂ (L¹H) and [CH{(Me)CN‐2‐ⁱPrC₆H₄}]₂ (L²H) were obtained from the reactions of trimethylaluminum, triethylaluminum with the corresponding β‐diketiminate, respectively. All compounds were characterized by ¹H NMR and ¹³C NMR spectroscopy, single‐crystal X‐ray structural analysis, and elemental analysis. Compounds 1 – 4 were found to catalyze the ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) with good activity.