Marcellino Rudyanto

Chrobisiamone A, a new bischromone from Cassia siamea and a biomimetic transformation of 5-acetonyl-7-hydroxy-2-methylchromone into cassiarin A.

A new bischromone, chrobisiamone A (1) with an antiplasmodial activity has been isolated from the leaves of Cassia siamea and the structure was elucidated by 2D NMR analysis. Cyclization of 5-acetonyl-7-hydroxy-2-methylchromone (2) in the presence of ammonium acetate resulted in generation of cassiarin A (3) with an unprecedented tricyclic skeleton, supporting a biogenetic pathway proposed for 3.

Propylparaben: physical characteristics.

Publisher Summary The chapter discusses the physical characteristics of propylparaben. Propylparaben occurs as odorless, tasteless, colorless crystals, or a white crystalline powder. Nomenclature, formulae, and elemental analysis of propylparaben are given. The reported dissociation constant (pKa) of propylparaben is 8.4 at 22°C. Partition coefficients for propylparaben in vegetable oils and water are given. Propylparaben has been reported to be very slightly soluble in water, but freely soluble in alcohol and ether. The solubilities of propylparaben in various solvents, and the solubilities of propylparaben in water at 25°C as a single component and in mixtures with other parabens are discussed. Crystals of propylparaben are translucent and colorless, belonging to the monoclinic system. Photomicrographs of crystalline propylparaben, obtained using optical microscopy are described. The chapter presents the crystallographic properties of propylparaben. The melting point of propylparaben is reported to be 95–99°C. The mass spectrum of propylparaben was recorded using a JEOL JMS-DX-303 spectrometer, operated in the electron impact mode. Propylparaben is known to be stable in contact with air, but the bulk substance should still be stored in a cool, dry place in a well-closed container. Propylparaben, along with its metabolites, was found in blood and urine after its oral and intravenous administration.

Synthesis and Pain Inhibition Activity of the Analogs of 1-Allyl-3-Benzoylthiourea for New Analgesic Lead Compound Discovery

Objective: The study aimed to synthesize four analogs of 1-allyl-3-benzoylthiourea (R= H; 2-Cl; 3-Cl; and 4-Cl), and evaluate their pain inhibition activities. Method: The chemical structure was drawn assisted by Chem- Draw Ultra 8.0 and Chem3D Ultra 8.0 software. Molegro Virtual Docker 5.0 software was utilized for the docking process, to determine the interaction energy values between compounds of interest and the COX-2 receptor (PDB: 1PXX). The synthesis step was done by nucleophilic substitution (benzoylation) on allylthiourea compound via modified Schotten-Baumann reaction. Chemical structure analysis was evaluated by means of Infra-Red, Nuclear Magnetic Resonance, and Mass Spectroscopy methods. The pain inhibition assay was done using acetic acid induced writhing test, using mice ( Mus musculus) as animal model. Results: Preliminary in silico screening showed that all four candidate compounds possessed good interaction on COX-2 receptor. The synthesis process produced rendemen of the compounds vary between 15.2 %-47%. Chemical structure evaluation confirmed the structural match of the products as expected. Acetic acid induced writhing test in mice ( Mus musculus) showed that three compounds possessed a better pain inhibition activity compared to positive control diclofenac sodium. Conclusion: 1-allyl-3-benzoylthiourea analogs showed good pain inhibition activity. The compounds can serve as leads for analgesic activity through the inhibition of COX-2. Key words: Synthesis, 1-allyl-3-benzoylthiourea, COX-2, Analgesic, Lead Compound.