Determination of optimum conditions for pectinesterase extraction from soursop fruit (Anona muricata) using response surface methodology

Optimum conditions for the extraction of pectinesterase from soursop (Anona muricata) have been established. A fractional factorial design and response surface methodology was applied in this study, as a means of improving the method for developing an enzyme extraction procedure. Among the variables tested, NaCl and pH showed greater significant effects, while PVP, EDTA and incubation time seemed to have a lowering effect on the efficiency of pectinesterase extraction from soursop. The maximum enzyme extraction was obtained by using 1.92 M NaCl solution at pH 8.4

Antimicrobial activity of selected Malaysian plants

Methanolic extracts of seventeen Malaysian plants were screened against fungi, including yeast and candida, as well as gram negative and gram positive bacteria. Antimicrobial activities were present in extracts prepared from Borreria latifolia, B. selidens, Hedyotis diffusa, H. nudicaulis, Morinda elliptica, M. umbellata (Rubiaceae), Sida rhombifolia (malvaceae) and Vitex ovata (Verbenaceae). Extracts from S. rhombifolia and B. latifolia showed exreptionally high activity against Candida albicans, Ca. intermedia, Aspergillus ochraceous, Cunninghamella clegans and Pseudomonas aeruginosa. However, only moderate activity was observed against Bacillus cereus, Ba. megaterium and Ca. Iipolyuca. Extracts from Calophyllum inophyllum (Guttiferae), Entada sp. (Leguminosae), Eclipta alba (Compositae), Dendrotrophe umbellata (Santalaceae), Cardiospermum halicacabum (Sapindaceae), Glochidion lutcscens and Euphorbia prunifolia (Euphorbiaceae) gave negative results

Assessment of Heritage Property Values Using Multiple Regression Analysis and Rank Transformation Regression

The current practice of heritage property valuation is using sale comparison approach. However, there is a limitation in applying this approach for heritage property valuation because of unavailability of market evidence.  Therefore, the aim of this paper was to evaluate the capability of Multiple Regression Analysis and Rank Transformation Regression in assessing the values of heritage property. The original dataset consists of 893 commercial properties transacted from 2004 to 2014 in Kota Bharu, Kelantan Malaysia. After filtration process, only 25 units of shophouse heritage property were available and valid to be used. The findings indicate that even we adopted statistical methods of analysis to overcome the issue of unavailability of market evidence this still could not solve the problem. Hence, the findings of this research contribute to the need for an improved method for heritage property valuation by proposing an extended sale comparison using statistical analysis for future investigation

Testing the Use of Multiple Regression Analysis and Rank Transformation Regression for Heritage Property Valuation

The aim of this paper was to test the applicability of multiple regression analysis and rank transformation regression in assessing the values of private heritage property. The original dataset consists of 893 commercial properties transacted from 2004 to 2014 in Kelantan Malaysia. After filtration process, only 25 units of shophouse heritage property were available and valid to be used. The models have been constructed and their statistical performances have been compared. The results indicate that adopting statistical methods of valuation per se to overcome the issue of unavailability of market evidence could not solve the consequences of the limited data problem. Keywords: real estate; heritage property; multiple regression analysis; rank transformation regression eISSN 2398-4279 © 2019. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.&nbsp

Purification and properties of pectinesterase from soursop (Anona muricata) pulp

Two forms of pectinesterase were purified using the techniques of ammonium sulphate fractionation, ion-exchange chromatography and gel filtration. PE I had a specific activity of approximately 4 units mg−1 (43-fold), that of PE II was 6.4 units mg−1 (229-fold). These pectinesterases (PE I and PE II) had approximate molecular weights of 29 100 and 24 100, respectively, as estimated by gel filtration, and 31 000 and 28 000, respectively, as estimated by sodium dodecyl sulphate polyacrylamide electrophoresis. The optimum temperature for enzyme activity was shown to be 60 °C for both PE I and PE II. The activation energies of PE I and PE II were calculated as 36 kJ mol−1 and 42 kJ mol−1, respectively. The optimum pH values for both pectinesterases lie within the range 7.0–8.0. The Km value for PE I was 0.52 mg ml−1 and 0.0843 mg ml−1 for PE II. PE I had a maximum velocity (Vmax) of 154 μmol mg−1 min−1, and PE II a Vmax of 726 μmol mg−1 min−1

Antiviral and cytotoxic activities of some plants used in Malaysian indigenous medicine

Ethanolic extracts of 61 medicinal plants used in Malaysia were screened for antiviral and cytotoxic activities. Antiviral activity was tested against the herpes simplex type-1 (HSV-1) and vesicular stomatitis (VSV) viruses, and cytotoxicity was assayed using the HeLa cell line. Antiviral activity against both viruses was present in the extracts from Calotropis gigantea, Costus speciosus, Eugenia michelii, Hedyotis auricularia, Mentha arvensis, Orthosiphon aristatus, Polygonum minus and Ricinus communis (MIG: 0.002-0.1 mg/ml). The extracts from Alternanthera sessilis, Blumea chinensis, Eleusine indica, Euphorbia hirta, Freycinetia malaccensis, Leea indica and Solanum americanum were active in selectively inhibiting HSV-1 (0.001-0.1 mg/ml). Selective activity against VSV was shown by the extracts from Acalypha indica, Bertholletia excelsa, Cerbera manghas, Codiaeum variegatum, Plectranthus amboinicus, Centella asiatica, Mirabilis jalapa, Morinda elliptica, Oenanthe javanica, Piper sarmentosum and Premna odorata (MIG: 0.005-0.1 mg/ml). Gytotoxic activity was present in the extracts from Acalypha indica, Andrographis paniculata, Cerbera manghas, Codiaeum variegatum, Cosmos caudatus, Elephantopus scaber, Etlingera elatior, Eugenia michelii, Freycinetia malaccensis, Hibiscus rosa-sinensis,Cen~ella asiati~a, Lecythis ollaria, Mentha arvensis, Mirabilis jalapa, Morinda elliptica, Ocimum tenUlflorum, PIper sarmentosum and Polygonum minus (CD50: 0.001-0.1 mgjml).Co-existing antiviral and cytotoxic activities were shown by Eugenia michelii, Mentha arvensis and Polygonum minus

Soursop pectinesterases: thermostability and effect on cloud stability of soursop juice

The thermostability of two forms of purified pectinesterase from soursop fruit were studied. The heat stability data showed that PE I is more heat stable than PE II at pH 7.5. The D and Z values were evaluated in the range 45–75°C. The D values at 65°C were approximately 5.8 min and 3.3 min for PE I and PE II respectively. The changes in temperature required to increase the inactivation rate tenfold (Z value) were calculated at 8.5 and 8.6°C for PE I, PE II respectively. Both enzymes also tested positive for their ability to destabilise soursop juice cloud at 5 and 30°C. Cloud destabilisation by PE I occurred the fastest (large decrease in A 660 nm) in the natural juice at 30°C