Cellulosic value-added products from sugarcane bagasse

Cellulose - Sugarcane bagasse (SCB) is a major by-product of the sugarcane industry and one of the most common renewable and sustainable cellulosic materials for various industrial...     

Locally Factorisable Transformation Semigroups

A semigroup S is factorisable if S = GE = EG where G is a subgroup of S and E is the set of idempotents in S; and S is locally factorisable if eSe is factorisable for every e E. In this paper, we unify and extend results which characterise when certain transformation semigroups defined on a set are (locally) factorisable, and we consider the corresponding problem for the semigroup of linear transformations of a vector space.To Yupaporn Kemprasit, mentor of semigroup theorists in Thailand1991 Mathematics Subject Classification: 20M20The third section of this paper formed part of an MSc supervised by the first author. She greatly appreciates the help of her supervisor in this work; and the first two authors are grateful for the assistance of the third author in the preparation of this paper. The third author also acknowledges the generous support of Centro de Mathematica, Universidade do Minho, Portugal, during his visit in July–August 2000 when the paper was completed.     

Antioxidant Potential and Cytotoxic Effect of Isoflavones Extract from Thai Fermented Soybean (Thua-Nao)

Thua-nao, or Thai fermented soybeans, is a traditional Lanna fermented food in Northern Thailand. It is produced by using a specific bacterial species called Bacillus subtilis var. Thua-nao. We investigated the antioxidant activity and cytotoxic effect of isoflavones from Thua-nao. The phenolic compound contents and total flavonoid contents were determined by spectrophotometry. The antioxidant activity was examined using the ABTS, FRAP, and DPPH assays. The isoflavone contents and phenolic compositions were examined by the high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) techniques. The ability of isoflavones to inhibit human cancer cell growth was assessed by the MTT assay. The total phenolic content, total flavonoid content, and antioxidant activities of the isoflavones were 49.00 ± 0.51 mg GAE/g of dry extract (DE), 10.76 ± 0.82 mg QE/g of DE, 61.03 ± 0.97 µmol Trolox/g of DE, 66.54 ± 3.97 µM FeSO₄/g of DE, and 22.47 ± 1.92% of DPPH inhibition, respectively. Additionally, the isoflavone extracts from Thua-nao had high isoflavone contents and polyphenolic compound compositions, especially daidzein and genistein. The isoflavone demonstrated a weak inhibition of MCF-7 and HEK293 cancer cell growth. It has a high antioxidant component, which is beneficial and can be developed for new therapeutic uses. However, further studies on the benefits of Thua-nao should be performed for realizing better and more effective uses soon.