ABSTRACT:Lipase from Candida rugosa was immobilized by entrapment while polymerizing a poly(N-vinyl-2-pyrrolidone-co-styrene) [poly(VP-co-ST)] hydrogel using ethylene dimethacrylate (EDMA) as the crosslinking agent. The immobilized enzymes were used in the esterification reaction of oleic acid and butanol in hexane. The activities of the immobilized enzymes and the leaching ability of the enzyme from the support with respect to the different compositions of the hydrogels were investigated. The thermal, solvent, and storage stability of the immobilized lipases were also determined. The activities were relatively higher when the percent compositions of VP (
Lipase from Candida rugosa was immobilized on poly(N-vinyl-2-pyrrolidone-co-styrene) hydrogel (poly-(VP-co-ST)) with ethylene dimethacrylate and ␣,␣'-azoisobutyronitrile, which act as crosslinker and initiator, respectively. Three different compositions of monomers were used, namely VP(%):ST(%), 10:90, 50:50, and 70:30 (wt(%)/wt(%)). The immobilized lipases were used in the enantioselective esterification of (R,S)-2-(4-chlorophenoxy)-propanoic acid with n-tetradecanol. The optimum reaction condition of the enantioselective esterification for the native lipase and the poly(VP-co-ST) hydrogel immobilized lipases was determined with respect to temperature, solvents, and initial water activity (a w ). The optimum temperature obtained was 40°C, with the poly(VP-co-ST) hydrogel immobilized lipase VP(%)/ST(%):10:90 showing the highest enantiomeric excess. In the solvent effect studies, the best solvents for high enantioselectivity were chloroform and carbon tetrachloride. In the a w studies, optimum ␣ w for NL, VP(%):ST(%), 10:90, and 50:50 was 0.328, while for VP(%): ST(%), 70:30, it was 0.55.
In this paper, we investigate the potency of Leea indica locally known as Memali plant from Tasik Chini, Pahang as a potent antioxidant and antimicrobial agent. Antibacterial activity of root, stem and leaf extracts of L. indica was evaluated against skin disease caused-microb Staphylococcus aureus and Staphylococcus epidermidis. Antioxidant activity was assessed by 2,2 diphenyl-1-picrylhydrazyl ( DPPH) thin layer chromatography (TLC) and dot blot assay method. The dichloromethane (DCM) extracts of all three parts displayed obvious antibacterial effect compared to other extracts and DCM extracts from leaves was the most effective in inhibiting the growth of S. epidermis with inhibition zone (IZ) of 18 mm. The methanol extracts from stem scavenged DPPH radicals more effective than root and leaf extracts at a concentration as low as 0.19 mg/ml. The antibacterial and antioxidant properties of leaves and stem might be attributed to the high content of terpenoid and phenolic. Thus, Memali appears to be a promising source of bioactive ingredients with antioxidant and antimicrobial activity. Keywords: Leea indica, antimicrobial, antioxidant, phytochemicals, secondary metabolitesAbstrak Kertas kerja ini meliputi penyelidikan ke atas potensi pokok Leea indica dari Tasik Chini, Pahang yang juga dipanggil Memali sebagai agen antioksidan dan antimikrob. Bahagian akar, batang dan daun dipilih untuk kajian aktiviti antibakteria dan antioksidan di mana ujian antibakteria menggunakan bakteria penyakit kulit seperti Staphylococcus aureus and Staphylococcus epidermidis. Ujian antioksidan menggunakan kaedah kromatografi lapisan nipis 2,2 diphenyl-1-picrylhydrazyl (DPPH) dan ujian dot blot. Didapati ekstrak dari diklorometana (DCM) menunjukkan aktiviti antimikrob yang lebih tinggi berbanding dengan ekstrak lain dan ekstrak dari daun mempunyai aktiviti yang paling tinggi dengan zon perencatan 18 mm. Ujian antioksidan menunujukkan ekstrak metanol bahagian batang lebih efektif memerangkap radikal DPPH pada kepekatan serendah 0.19 mg/ml. Sifat antioksidan dan antimikrob ini berkemungkinan akibat daripada adanya kandungan bahan seperti terpen dan fenolik yang tinggi. Maka pokok Memali dilihat sebagai punca asas bahan bioaktif yang bersifat antimikrob dan antioksidan.
Entada spiralis Ridl. (Leguminosae) is a woody climber which locally known as 'akar sintok'. The isolation and structure determination of two crystalline solids from active methanol fraction of E. spiralis stem bark had been examined. The structure identification of both solids was based on spectroscopic data ( 1 H and 13 C NMR, HMQC, HMBC, DEPT135 and MS) along with comparison with literature data. The results revealed that these two crystalline solid sugars isolated from the most active fraction were known as penta-2-acetoxy-Thus, this finding can be utilized as a scientific baseline information for further skin disease studies, since both constituents were isolated from moderate antidermatophytic active fraction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.