Comparative extraction and simple isolation improvement techniques of active constituents’ momilactone A and B from rice husks of Oryza sativa by HPLC analysis and column chromatography

Experiments were conducted to identify allelochemicals from rice (Oryza sativa L.) straw extracts of four rice cultivars (Gin shun, Kasawala mundara, Philippine 2 and Juma 10), and to test their biological activity on barnyard grass (Echinochloa crus-galli P. Beauv. var. oryzicola Ohwi). High performance liquid chromatography (HPLC) analysis showed that the concentration and composition of allelopathic compounds depended on the cultivar. Among the compounds identified were p-hydroxybenzoic acid at 6.87 mg g–1 in Gin shun, p-coumaric acid at 0.34 mg g–1 in Kasawala mundara, ferulic acid at 0.05 mg g–1 in Philippine 2, and p-hydroxybenzoic acid at 6.34 mg g–1 in Juma 10. Preliminary identification by HPLC analysis resulted in peaks with retention times near those of standards, including p-hydroxybenzoic acid m/z = 138). This was confirmed with electron impact/mass spectra. In a bioassay with nine known allelochemicals and their mixtures, p-hydroxybenzoic acid (10–3 M) showed the greatest inhibitory effect on barnyard grass seed germination, seedling length, and dry weight. This suggests that this compound may be a key factor in rice allelopathy on barnyard grass. Key words: Allelopathic compound, rice, barnyard grass, bioassay

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Biofertilizer Formulation with Bioactivators Bacillus cereus on the Growth and Yeild of Upland Rice (Oryza sativa L.) in Peat Medium

Asian Journal of Applied Sciences ◽

10.24203/ajas.v9i3.6666 ◽

2021 ◽

Vol 9 (3) ◽

Author(s):

Hapsoh ◽

Wawan ◽

Isna Rahma Dini ◽

Devi Andriani

Keyword(s):

Oryza Sativa ◽

Bacillus Cereus ◽

Upland Rice ◽

Oryza Sativa L ◽

Growth And Yield ◽

Soil Science ◽

Science Laboratory ◽

Rice Husks ◽

Randomized Design ◽

Completely Randomized Design

This study aims to test the bio-fertilizer formulation with Bacillus cereus bioactivator and to obtain the best bio-fertilizer formulation for the growth and yield of upland rice (Oryza sativa L.) in peat medium. The research was conducted in the experimental garden and Soil Science Laboratory, Faculty of Agriculture, University of Riau from July to October 2018. The study was carried out experimentally using a completely randomized design (RAL) with the treatment tested was the formulation of Bacillus cereus (F): F0: 100 ml Bacillus cereus without formulation, F1: 100 ml Bacillus cereus inoculant+74% bagasse+13% dolomite+13% zeolite, F2: 100 ml Bacillus cereus inoculant+74% rice husk+13% zeolite+13% dolomite, F3: 100 ml inoculant Bacillus cereus+74% solid+13% dolomite+13% zeolite, F4: 100 ml Bacillus cereus inoculant+74% tkks+13% zeolite+13% dolomite. The data obtained were analyzed statistically using variance fingerprints. The average result of the analysis was continued with the BNJ test at the 5% level. The results showed that administration of Bacillus cereus without formulation and with the formulation of solid organic matter of rice husks, solids and oil palm empty bunches showed a good response to the amount of chlorophyll and yield of upland rice plants.

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Benzyl (R)-2-(Acetylthio)Propanoate: A Promising Sulfur Isoster of (R)-Lactic Acid and Ester Precursors

Molbank ◽

10.3390/m1010 ◽

2018 ◽

Vol 2018 (3) ◽

pp. M1010

Author(s):

Ryosuke Sasaki ◽

Momoyo Kawamoto ◽

Yoo Tanabe

Keyword(s):

Lactic Acid ◽

Column Chromatography ◽

Hplc Analysis ◽

Enantiomeric Excess ◽

Propanoic Acid ◽

Displacement Reaction ◽

Acetyl Group ◽

Benzyl Esters ◽

Sulfur Containing

In this paper, an accessible chiral pool synthesis of benzyl (R)-2-(acetylthio)propanoate (acetylthiolactate), which is less odorous than the methyl or ethyl analogue, was performed through a clean SN2 displacement reaction using available AcSK with tris[2-(2-methoxyethoxy)]ethylamine (TDA-1), starting from commercially available benzyl (S)-lactate in 76%, 94% ee (2 steps). Deprotection of the acetyl group using N,N-dimethylethylenediamine afforded benzyl (R)-2-sulfanylpropanoate in 93% yield with 90% ee. These two sulfur-containing benzyl esters were sufficiently odorless to be purified by column chromatography. Direct HPLC analysis was applied to determine the enantiomeric excess without thiazolidin-4-one derivatizations. A complementary debenzylation of benzyl (R)-2-(acetylthio)propanoate was also performed using HBr/AcOH to afford (R)-2-(acetylthio)propanoic acid without critical racemization in 92% yield with 92% ee.

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Structural Characteristics of the Guaiacyl-Rich Lignins From Rice (Oryza sativa L.) Husks and Straw

Frontiers in Plant Science ◽

10.3389/fpls.2021.640475 ◽

2021 ◽

Vol 12 ◽

Author(s):

Mario J. Rosado ◽

Jorge Rencoret ◽

Gisela Marques ◽

Ana Gutiérrez ◽

José C. del Río

Keyword(s):

Oryza Sativa ◽

Rice Straw ◽

Oryza Sativa L ◽

Structural Characteristics ◽

Analytical Techniques ◽

Gas Chromatography Mass Spectrometry ◽

Aryl Ether ◽

Rice Husks ◽

Alkyl Aryl ◽

G Ratio

Rice (Oryza sativa L.) is a major cereal crop used for human nutrition worldwide. Harvesting and processing of rice generates huge amounts of lignocellulosic by-products such as rice husks and straw, which present important lignin contents that can be used to produce chemicals and materials. In this work, the structural characteristics of the lignins from rice husks and straw have been studied in detail. For this, whole cell walls of rice husks and straw and their isolated lignin preparations were thoroughly analyzed by an array of analytical techniques, including pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC/MS), nuclear magnetic resonance (NMR), and derivatization followed by reductive cleavage (DFRC). The analyses revealed that both lignins, particularly the lignin from rice husks, were highly enriched in guaiacyl (G) units, and depleted in p-hydroxyphenyl (H) and syringyl (S) units, with H:G:S compositions of 7:81:12 (for rice husks) and 5:71:24 (for rice straw). These compositions were reflected in the relative abundances of the different interunit linkages. Hence, the lignin from rice husks were depleted in β–O–4′ alkyl-aryl ether units (representing 65% of all inter-unit linkages), but presented important amounts of β–5′ (phenylcoumarans, 23%) and other condensed units. On the other hand, the lignin from rice straw presented higher levels of β–O–4′ alkyl-aryl ethers (78%) but lower levels of phenylcoumarans (β–5′, 12%) and other condensed linkages, consistent with a lignin with a slightly higher S/G ratio. In addition, both lignins were partially acylated at the γ-OH of the side-chain (ca. 10–12% acylation degree) with p-coumarates, which overwhelmingly occurred over S-units. Finally, important amounts of the flavone tricin were also found incorporated into these lignins, being particularly abundant in the lignin of rice straw.

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Photoreduction of mercury metal (Hg) using catalyst of oxalic acid from cellulose of rice husks (Oryza sativa L.)

10.1063/1.4946961 ◽

2016 ◽

Author(s):

Ade Sumiardi ◽

Cory Novi ◽

Esih Sukaesih ◽

Aji Humaedi

Keyword(s):

Oryza Sativa ◽

Oxalic Acid ◽

Oryza Sativa L ◽

Rice Husks

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Composite from high density polyethylene (HDPE) reinforced with rice husks (Oryza sativa): Preparation and mechanical property

Malaysian Journal of Chemical Engineering and Technology (MJCET) ◽

10.24191/mjcet.v3i2.10941 ◽

2020 ◽

Vol 3 (2) ◽

pp. 25

Author(s):

Norin Zamiah Kassim Shaari ◽

Ahmad Redha Taha ◽

Suhaiza Hanim Hanipah

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Oryza Sativa ◽

Citric Acid ◽

Rice Husk ◽

High Density Polyethylene ◽

Extrusion Process ◽

Rice Husks ◽

Flexible Material ◽

Processing Ability

In this study, the composite from HDPE polymer was formulated with the incorporation of Oryza sativa also known in general as rice husks or hulls with two different methods: with the incorporation of plasticiser (glycerol and citric acid) and without plasticisers. The ratio of glycerol to citric acid used in the experiment was 1:2. The aim of this study is to determine the effect of incorporating rice husk with different fibre sizes on the mechanical properties of the HDPE composite. The blending of HDPE with the rice husk was performed in a mixer in processing compounding polymer followed by the extrusion process. Results show that in the absence of the plasticiser, rice husk portrays good compatibility with HDPE polymer, where the composite possessed good tensile strength and elongation. The best plasticising effect was portrayed by filler with 100 µm as it yields the highest tensile strength and strain. In conclusion, the composite could be potentially used for suitable applications, which requires flexible material with better processing ability and would not be brittle.

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HIDROLISIS SELULOSA DARI SEKAM PADI (Oryza sativa) MENJADI GLUKOSA DENGAN KATALIS ARANG TERSULFONASI

KOVALEN ◽

10.22487/j24775398.2016.v2.i3.7536 ◽

2016 ◽

Vol 2 (3) ◽

Author(s):

Adeks Pramana ◽

Abdul Rahman Razak ◽

Prismawiryanti Prismawiryanti

Keyword(s):

Oryza Sativa ◽

Sulfuric Acid ◽

Acid Concentration ◽

Rice Husk ◽

Contact Time ◽

Sulfuric Acid Concentration ◽

Cellulose Hydrolysis ◽

Hydrolysis Reaction ◽

Rice Husks ◽

Hydrolysis Of

Cellulose hydrolysis from rice husk (Oryza sativa) into glucose with sulfonated charcoal catalyst was conducted. The aim of this research was to determine sulfuric acid concentration and contact time on the sulfonation process of charcoal which would produce the highest glucose rendement from cellulose hydrolysis of rice husk. Sulfuric acid concentrations in this experiment were 8, 10, and 12 N with variation of contact time of 4, 6, 8, 10 and 12 hours respectively. Rice husk was delignified with NaOH 10% to produce cellulose which was hydrolyzed by sulfonated charcoal catalyst. Hydrolysis reaction with the ratio cellulose/aquadest 1:25 (w/v) was conducted in autoclave with temperature 130 oC for 3 hours. The result showed that 8 N concentration of sulfuric acid and 12 hours of contact time produced the highest glucose rendement 17,9%. Keywords : rice husks, cellulose, glucose, sulfonated charcoal

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