Direct deuteration of hinokitiol and its mechanistic study

ABSTRACT Hinokitiol has a broad antibacterial activity against bacteria and fungi. While its biosynthetic pathway has been intensively studied, its dynamics in natural environments, such as biodegradation pathway, remain unclear. In this study, the authors report a direct deuterium labeling of hinokitiol as a traceable molecular probe to serve those studies. Hinokitiol was subjected to the H2-Pd/C-D2O conditions and deuterated hinokitiol was obtained with excellent deuteration efficiencies and in moderate yield. The 1H and 2H NMR spectra indicated that all ring- and aliphatic hydrogens except that on C-6 were substituted by deuterium. According to the substrate scope and computational chemistry, deuteration on tropolone ring was suggested to proceed via D+-mediated process, and which was supported by the results of the experiment with trifluoroacetic acid and Pd(TPP)4. On the other hand, the deuteration on aliphatic group was predicted to be catalyzed by Pd(II) species.

Chemical structure changes of marine shale caused by supercritical carbon dioxide

The interaction between shale and CO2 is of great significance to CO2 storage and shale gas production; however, there are few reports on chemical changes after CO2 injection into shale reservoirs. We used Fourier transform infrared spectroscopy to study the chemical structure changes of shale samples before and after CO2 injection. In this paper, self-developed high-temperature and high-pressure vessels were used to examine CO2 treatment of shale to simulate the stratigraphic environment and infrared was used to study the influence of changes in pressure and temperature on the chemical interaction between shale and CO2. These results showed that: (1) after shale CO2 treatment, the number of functional groups remained unchanged, though the content and structure of the shale did change; (2) pressure increases reduced hydroxyl and aliphatic group levels in the shale; the branched-chain and aromaticity indexes of the shale were reduced by 81.5% and 53.8%, respectively, relative to untreated samples; (3) below 60°C, free water in the shale increased with temperature increases and dissolution of the shale increased; however, above 60°C, dissolution was inhibited which resulted in precipitation; (4) the dissolution degree of shale carbonate minerals positively correlated with CO2 pressure and temperature, while silicate minerals were unchanged CO2 pressure and temperature. Finally, the change of CO2 pressure had a more significant influence on the chemical structure of shale. These results provide a basis for the continuing study of the influence of chemical structure change of shale caused by CO2 on shale wettability and enhance the theoretical level of CO2 shale mining.

Senyawa Saponin Hasil Isolasi dari Daun Buni (Antidesma bunius (L.) Spreng.)

Tanaman buni (Antidesma bunius (L.) Spreng.) secara tradisional telah digunakan untuk hipertensi, takikardia, anemia, sifilis, antikanker, antioksidan, sumber pewarna alami dan antidiabetes. Saponin merupakan senyawa fitokimia yang mempunyai kemampuan membentuk busa dan mengandung aglikon polisiklik yang berikatan dengan satu atau lebih gula. Penelitian ini bertujuan untuk melakukan karakterisasi senyawa saponin hasil isolasi dari daun buni dengan spektrofotometer ultraviolet dan inframerah. Simplisia daun buni dilakukan karakterisasi kemudian diekstraksi dengan cara maserasi bertingkat menggunakan pelarut n-heksana dan etanol 80%. Selanjutnya ekstrak etanol dihidrolisis dengan HCl 2N kemudian difraksi dengan pelarut kloroform. Isolasi dilakukan terhadap fraksi kloroform dengan cara kromatografi lapis tipis preparatif menggunakan fase diam silika gel GF254 dan fase gerak yang sesuai. Isolat yang diperoleh diuji kemurnian dengan KLT 2 arah dan dikarakterisasi menggunakan spektrofotometer ultraviolet dan inframerah. Hasil pemeriksaan karakterisasi simplisia diperoleh kadar air 7,32%, kadar sari larut dalam etanol 52,70%, kadar sari larut dalam air 23,25%, kadar abu total 6,86% dan kadar abu tidak larut dalam asam 0,94%. Pemisahan fraksi kloroform dengan KLT menggunakan fase gerak n-heksana-etilasetat perbandingan 5:5 diperoleh noda 13 dan hasil KLT preparatif diperoleh 2 isolat murni yaitu isolat 1 (ungu merah) dengan Rf 0,92 dan isolat 2 (biru) dengan Rf 0,78. Hasil karakterisasi isolat 1 diperoleh panjang gelombang maksimum pada 208 nm dan dijumpai adanya gugus hidroksil, gugus -CH alifatis, ikatan C=C, gugus –CH2, gugus –CH3, dan gugus C-O. Hasil karakterisasi isolat 2 diperoleh panjang gelombang maksimum pada 204 nm dan adanya gugus hidroksil, gugus -CH alifatis, gugus –CH2, gugus –CH3, dan gugus C-O. Buni (Antidesmabunius (L.) Spreng.) has been traditionally used for the treatment of hypertension, tachycardia, anemia, syphilis, and used asanti-cancer, anti-oxidant, natural dye, and anti-diabetic. Saponin is a phytochemical compound which has capability in forming foam and contains polycyclic aglycone that binds with one or more glucose. This research aimed to conduct the characterization of saponin compound from buni leaves with ultraviolet spectrophotometer and infrared. Buni leaves simplicia was characterizedand extracted using sequential maceration method with n-hexane and 80% ethanol. The ethanol extract was hydrolyzed with HCl 2N and fractionized using chloroform solvent. Isolation of chloroform fraction was done using preparative thin-layer chromatography using silent phase of silica gel GF 254 and suitable mobile phase. Isolates obtained was taken into purity test with two dimensions thin-layer chromatography and characterized using ultraviolet spectrophotometer and infrared. The characterized simplicia resulted with 7.32% of water content, 52.70% of dissolved content in ethanol, 23.25% of dissolvedcontent in water, 6.86% of total ash content, and 0.94% of undissolved ash content in acid. Fractinationof chloroform fraction with thin-layer chromatography using mobile phase ofn-hexane-ethyl acetate with 5:5 ration resulted with 13 spotsand the result of the preparative thin-layer chromatography resulted 2 pure isolates which are isolate 1 (purple-red) with Rf 0.92 and isolate 2 (blue) with Rf 0.78. The characterization of isolate 1 resulted that the maximum wave lengthwas 208 nm with hydroxyl group, –CH aliphatic group, C=C bond, –CH2 group, –CH3 group, and C–O group. The characterization of isolate 2 resulted that the maximum wave lengthwas204 nm with hydroxyl group, –CH aliphatic group, –CH2 group, –CH3 group, and C–O group.

Characterization of Humic Substance Extracted from Andisols, Spodosols, Peat, and Lignite

Soil and other materials with high C-organic content are potential natural sources of humic substances. Until now the differences in the characteristics of such humic substances that are extracted from different sources have not been widely studied. Thus, this study was aimed to characterize humic substances extracted from andisols, spodosols, peat, and lignite. The highest C-organic (48.8%) and N (7.6%) were obtained from peat and spodosols, respectively. The andisols humic substance produced the highest total acidity (6.52 cmol kg^-1). Humic substance extracted from spodosols was a mostly aliphatic group and phenolate –OH, while that of andisols and lignite contained more aromatic group and phenolate –OH, whereas the humic substance from peat was a predominantly aliphatic group and –COOH. The surface morphology of the humic substances observed using SEM showed varying densities and shapes due to differences in their respective degree of decomposition and the formation process involved. There has been significant interest in investigating the different characteristics of the humic substance. The type humic substances are important to be known considering of their positive effects on soil fertility and plant growth and development.

THE UTILIZATION OF GLYCEROL, BIODIESEL SIDE PRODUCT OF USED COOKING OIL AS GLYCEROL ACETATE MATERIAL SYNTHESIS

The research aimed at using glycerol of biodiesel synthesis side product from used cooking oil as glycerol acetate material synthesis, and charactering synthesized material based on data of IR spectroscopy and GCMS. The method used to synthesize glycerol acetate was refl ux during 50 minute at 80C. Glycerol from biodiesel synthesis side product from used cooking oil was purifi ed with acetic anhydride reacted at 80 0C, for 50 minutes. The synthesisproduct was characterized by IR and GCMS spectroscopies. The result of this research shows that glycerol derived from synthesizing glycerol 1–monoacetate and glycerol 2-monoacetate in the form of yellow liquid with 145-148 0C boiling point, soluble in ethanol and insoluble in n-hexane. IR spectrum shows the presence of C=O carbonyl, C-O ester, -OH, and C-H aliphatic group; GCMS spectrum shows a mixture from two glycerol monoacetate with SI (Similiar Index) of 97 and 93

Rearrangement of aldoximes to amides in water under air atmosphere catalyzed by water-soluble iridium complex [Cp*Ir(H2O)3][OTf]2

R = aryl or aliphatic group phosphorous ligand-free low catalytic loading under air atmosphere up to 93% yield; 37 examples.

The pentafluorosulfanyl group in cannabinoid receptor ligands: synthesis and comparison with trifluoromethyl and tert-butyl analogues

Competitive CB1 receptor antagonists carrying an aromatic SF5 group in position 3 of a pyrazole ring were synthesised and compared with their CF3 and tert-butyl analogues. Results confirmed that an aromatic SF5 group can be used as a bioisosteric analogue of a CF3 group and possibly of a bulky aliphatic group too.