Investigation of the effect of plasticizer injection technology on the properties of epichlorohydrin rubbers

The influence of preliminary swelling of epichlorohydrin rubber of the brand is investigated Hydrin Т6000 in dioctyl adipate and dioctyl sebacate on the Physicomechanical characteristics and frost resistance of its vulcanizates. Revealed that pre-swelling of the rubber in the plasticizer, the plasticizer penetrates into the intermolecular space of the rubber and due to the shielding effect reduces the interaction of the filler with the elastomer matrix, which simultaneously leads to improved low-temperature properties and decrease of Physicomechanical properties of vulcanizates.

Antimalarial Activity of Andrographis Paniculata Ness‘s N-hexane Extract and Its Major Compounds

Andrographis paniculata Ness is one of the plants that is under explored and could contain potentially active substances to serve as an antimalarial. Structure investigation of major compounds that have responsibility for the antimalarial activity of Andrographis paniculata Ness’s n-hexane extract is very important so that it is known whether the antimalarial activity is synergistic or from the major compounds. Menthol and dioctyladipate as major component from n-hexane extract of Andrographis paniculata Ness have been succesfully isolated using simple and inexpensive methods. The solvent system used are n-hexane : ethyl acetate (10:1) and n-hexane: chloroform (10:3) consecutively either for column or preparative thin layer chromatography. FT-IR, 1H-NMR and GC-MS were used to determine the structure of compounds. The activity of n-hexane extract, menthol and dioctyladipate related to the inhibition of heme polymerization have been done comprehensively. The inhibition of heme polymerization activity of isolate compounds and n-hexane extract are classified to a good level (dioctyl adipate IC50 = 1.15 ± 0.41 mg/mL, menthol IC50 = 0.31 ± 0,01 mg/mL, and n-hexane extract IC50 = 0.07 ± 0.03 mg/mL) and potentially as antimalarial. From the IC50, the antimalarial activity of Andrographis paniculata Ness’s n-hexane extract is working synergistically, not by the major compounds.

PENGARUH DIOCTYL ADIPATE TERHADAP SIFAT RHEOLOGIKAL HTPB TERPLASTISISASI (EFFECT OF DIOCTYL ADIPATE ON THE RHEOLOGICAL PROPERTIES OF PLASTICIZED HTPB)

Pengembangan pengetahuan terhadap sifat rheologikal isian cair dari propelan berguna untuk mendapatkan sifat slurry yang optimum. Pengembangan ini dapat dimulai dari campuran HTPB-DOA sehingga penelitian ini bertujuan untuk mengetahui pengaruh DOA terhadap sifat rheologikal HTPB-DOA yang meliputi sifat alir terhadap shear rate, viskositas dan viskositas saat zero shear rate. Dalam metodenya, DOA divariasi 0, 5, 10, 15 dan 20% dan dicampur dengan HTPB. Sifat rheologikal dipahami dengan mengukur viskositasnya pada kecepatan putar 0,5; 1; 1,5; 2; 2,5; 3; 4 dengan spindel tipe 2 dari viskometer Brookfield dan menganalisa grafik shear stress vs shear rate serta viskositas vs shear rate. Berdasarkan analisa tersebut, diketahui bahwa campuran HTPB-DOA bersifat shear thickening. Semakin banyak DOA yang ditambahkan, semakin rendah viskositas campuran, semakin rendah nilai viskositas pada zero shear rate dan semakin kuat sifat shear thickening dari campuran.

Identification and Analysis of Secondary Metabolites from CH3OH/H2O Extract of Metacordyceps Neogunnii

Secondary metabolites are considered to be the major compounds in Cordyceps with anti-tumor, anti-aging and immunity-enhancing effects. The molecular structures of secondary metabolites form the basis for the development and utilization of Cordyceps. Metacordyceps neogunnii is an important Cordyceps resource, but less study has been made on the molecular structure of its secondary metabolites. In this study, gas chromatography-mass spectrometry (GC/MS) and ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) were used to analyze and identify the secondary metabolites from CH3OH/H2O extract of Metacordyceps neogunnii. The results show that a total of 22 compounds were identified by GC-MS, including 2 n-alkanes, 1 isoparaffin, 1 cycloalkane, 6 olefins and 13 esters. The predominant compounds were (E)-ocimene, (E)-β-ocimene, methyl oleate, dioctyl adipate, methyl palmitate and methyl linoleate, obtained by means of GC/MS. Five distince classes of secondary metabolites were speculated: 3 polypeptides, 2 esters, 1 isoflavone, 1 isoindrone and 3 amides, from which 10 compounds were detected using UPLC-Q-TOF/MS. (R)-N-((1-(((9H-fluorene-9-yl) methoxy) carbonyl) pyrrolidine-2-yl) methyl)-N-(2-(6-benzoylamino-9H-purin-9-yl) acetyl) glycine, benzyl (5-(2-((3-(2, 3-dihydrobenzo[b] [1, 4] dioxin-6-yl)-4-carbonyl-4H-chromene-7-yl) oxo) acetylamino) amyl) carbamate, 5, 5’-((propane-2, 2-diyl (4, 1-phenylene)) bis (oxo)) bis (2-(naphthalene-1-yl) isoindoline-1, 3-dione), 1-dodecylazepine-2-one and other compounds were the first detected in Metacordyceps neogunnii.