2-Methyl-2-(2-pyrid­yl)hexa­hydro­pyrimidine

In the aminal-type title compound, C10H15N3, the six-membered hexa­hydro­pyrimidine ring adopts a chair conformation and the N atoms are pyramidally coordinated. One of the two amido –NH units engages in inter­molecular hydrogen bonding with the pyridyl N atom, generating a helical chain running along the b axis of the ortho­rhom­bic unit cell

Evaluation and characterisation of Citrullus colocynthis (L.) Schrad seed oil: comparison with Helianthus annuus (sunflower) seed oil.

The physicochemical properties, fatty acid, tocopherol, thermal properties, 1H NMR, FTIR and profiles of non-conventional oil extracted from Citrullus colocynthis (L.) Schrad seeds were evaluated and compared with conventional sunflower seed oil. In addition, the antioxidant properties of C. colocynthis seed oil were also evaluated. The oil content of the C. colocynthis seeds was 23.16%. The main fatty acids in the oil were linoleic acid (66.73%) followed by oleic acid (14.78%), palmitic acid (9.74%), and stearic acid (7.37%). The tocopherol content was 121.85 mg/100 g with γ-tocopherol as the major one (95.49%). The thermogravimetric analysis showed that the oil was thermally stable up to 286.57 °C, and then began to decompose in four stages namely at 377.4 °C, 408.4 °C, 434.9 °C and 559.2 °C. The present study showed that this non-conventional C. colocynthis seed oil can be used for food and non-food applications to supplement or replace some of the conventional oils

5,5-Dimethyl-2,2-bis­(pyridin-2-yl)-1,3-diazinane

In the mol­ecule of the title compound, C16H20N4, the 1,3-diazinane ring adopts a chair conformation and the dihedral angle formed by the pyridine rings is 78.64 (8)°. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯N hydrogen bond, forming an S(6) ring motif. In the crystal, centrosymmetrically related mol­ecules are linked into dimers by pairs of N—H⋯N hydrogen bonds, generating rings of R 2 2(10) graph-set motif

Bitter and sweet lupin (Lupinus albus L.) seeds and seed oils : a comparison study of their compositions and physicochemical properties

In this study, bitter and sweet lupin (Lupinus albus L.) seed oils (BLO and SLO) were extracted using the soxhlet extraction method. The physicochemical properties, fatty acid compositions, thermal properties, 1H NMR, FTIR and UV visible spectra of BLO and SLO were evaluated. In addition, the antioxidant properties of bitter and sweet lupin seeds and their oils were also studied. The results showed that the bitter and sweet lupin seeds consist of 8% and 12% of oil, respectively. BLO and SLO contained high concentration of oleic acid (46.28 and 48.72%), followed by linoleic acid (21.55 and 20.90%), linolenic acid (7.69 and 8.95%), and palmitic acid (7.39 and 7.5%). The total tocopherol content of BLO and SLO were 184.70 and 317.01 mg/100 g oil, respectively. TG/DTG curves showed that the process thermal decomposition of the oils occurs in four phases for SLO and three phases for BLO

Post-functionalization of polymeric mesoporous C@Zn coreeshell spheres used for methyl ester production

In the present study, the mesoporous carbon@zinc (C@Zn) core-shell spheres were hydrothermally synthesized, using polyethylene glycol (PEG) as the surfactant and d-glucose as the pore forming agent. Then, the post-sulfonation treatment was carried out to prepare polymeric mesoporous SO3H-ZnO catalyst. The physicochemical, structural, textural and morphological properties of the synthesized catalysts were characterized by X-ray powder diffraction (XRPD), surface area analysis (Brunauer–Emmett–Teller equation), temperature programed desorption (TPD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The polymeric mesoporous SO3H-ZnO catalyst owned a high surface area of 396.56 m2/g with the average pore size of 3.45 nm and acid strength of 1.92 ± 0.05 mmol/g. The catalytic activity of the synthesized catalyst was further studied via esterification of the palm fatty acid distillate (PFAD), using a microwave-assisted technique. The biodiesel yield of 91.20% was achieved under the optimized esterification conditions as follows: the methanol to PFAD molar ratio of 9:1, catalyst concentration of 1.5 wt%, reaction temperature of 90 °C and reaction time of 15 min. The spent mesoporous catalyst was highly stable for reuse with nine continuous runs without further treatment

N′-(Di-2-pyridylmethyl­ene)benzo­hydrazide

In the title Schiff base, C18H14N4O, the amido –NH– unit is connected to one of the two pyridyl N atoms at an N(—H)⋯N distance of 2.624 (2) Å. The mol­ecular packing features an inter­molecular C—H⋯N R 2 2(6) hydrogen-bonding ring motif

Composición química, estabilidad oxidativa y actividad antiproliferativa del extracto de hexano de semilla de Anethum graveolens (eneldo)

This study aimed to evaluate the physicochemical properties, chemical composition, and anti­proliferative activity of the hexane extract of Anethum graveolens L. (dill) seeds using gas chromatography mass spectrometry (GC-MS). Two fractions, namely the lipid fraction (74%) and volatile fraction (26%), were detected. The extract content of the seeds was about 9.4% and the extract had a pleasant spicy aroma. Oleic acid (52%), cis-vaccenic acid (6.2%), linoleic acid (5.5%), and palmitic acid (3.3%) were the key fatty acids in the lipid fraction, while apiol (23%) and d-carvone (2.4%) were the major volatile components. Tocols (tocopherols and tocotrienols) were also detected in the A. Graveolens extract (155 mg/100 g) and b-tocopherol was identified as the major tocol (71%). Dill extract showed a high oxidative stability (induction time = 45.22 h). Furthermore, dill extract showed antiproliferative activity against breast cancer cell lines.Este estudio tuvo como objetivo evaluar las propiedades fisicoquí­micas, la composición química y la actividad antiproliferativa del extracto de hexano de semillas de Anethum graveolens L. (eneldo) mediante cromatografía de gases con espectrometría de masas (GC-MS). Se detectaron dos fracciones, la fracción lipídica (74%) y la fracción volátil (26%). El contenido del extracto de las semi­llas fue de aproximadamente 9,4% y el extracto tenía un agradable aroma picante. Los ácidos oleico (52%), cis-vaccénico (6,2%), linoleico (5,5%) y palmítico (3,3%) fueron los ácidos grasos clave en la fracción lipídica, mientras que el apiol (23%) y la d-carvona (2,4%) fueron los principales componentes volátiles. También se detectaron tocoles (tocoferoles y tocotrienoles) en el extracto de A. Graveolens (155 mg/100 g) y se identificó el β-tocoferol como el principal tocol (71%). El extracto de eneldo mostró una alta estabilidad oxidativa (tiempo de inducción = 45,22 h). Además, el extracto de eneldo mostró actividad antiproliferativa contra las líneas celulares de cáncer de mama

Conversión de Oleum papaveris seminis en ésteres metílicos mediante un proceso de esterificación: Optimización y estudio cinético

This paper presents an acid pre-treatment process and a kinetic study for the esterification reaction of Oleum papaveris seminis oil with methanol in the presence of amberlite 120 as a solid catalyst to convert the oil into methyl esters. Response surface methodology (RSM) was applied to optimize the reaction parameters, i.e. reaction time, percentage of the catalyst and volume ratio of methanol to oil. The results revealed that 0.87% w/w of catalyst concentration and 44.70% v/v of methanol to oil ratio provided final free fatty acid (FFA) contents of 0.60% w/w at 102.40 min of reaction time. It proved that the contribution of Amberlite 120 in the esterification of FFA was highly significant. The kinetics of the esterification in Oleum papaveris seminis oil with methanol in the presence of the amberlite 120 catalyst were also investigated to establish the reaction rate constant (k), reaction order, and activation energy. The study was performed under the optimized parameters at three reaction temperatures (50, 55, and 60 ºC). The value of k was in the range of 0.013 to 0.027 min-1. The first-order kinetics’ model was suitable for this irreversible FFA esterification with the activation energy of about 60.9 KJ·mol-1.En este artículo se presenta un proceso de pre-tratamiento con ácido, y un estudio cinético de la reacción de esterificación. Se utiliza Oleum papaveris seminis con metanol en presencia de Amberlite 120 como catalizador sólido para la formación de los ésteres metílicos. Se aplicó una metodología de superficie de respuesta (RSM) para optimizar los parámetros de la reacción; es decir, tiempo de reacción, porcentaje de la relación de catalizador y volumen de metanol - aceite. Los resultados mostraron que el 0,87% w/w de la concentración de catalizador y 44,70% v/v de metanol en relación al aceite dan lugar a un contenido final de ácidos grasos libres (FFA) de 0,60% w/w en 102,40 min de tiempo de reacción. Se demostró que la contribución de Amberlite 120 en la esterificación de los FFA fue altamente significativa. La cinética de la esterificación del Oleum papaveris Seminis con metanol en presencia del catalizador Amberlite 120 también se investigó para establecer la constante de velocidad de reacción (k), orden de la reacción, y la energía de activación. El estudio se realizó bajo los parámetros optimizados a tres temperaturas de reacción (50, 55, y 60 °C). El valor de la constante k fué del rango de 0.013 a 0,027 min-1. El modelo de cinética de primer orden fue el adecuado para esta esterificación FFA irreversible con una energía de activación de aproximadamente 60,9 KJ mol -1