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71.
Mamtesh Singh Prasun Kumar Subhasree Ray Vipin C. Kalia 《Indian journal of microbiology》2015,55(3):235-249
Polyhydroxyalkanoates (PHAs) as an alternative to synthetic plastics have been gaining increasing attention. Being natural in their origin, PHAs are completely biodegradable and eco-friendly. However, consistent efforts to exploit this biopolymer over the last few decades have not been able to pull PHAs out of their nascent stage, inspite of being the favorite of the commercial world. The major limitations are: (1) the high production cost, which is due to the high cost of the feed and (2) poor thermal and mechanical properties of polyhydroxybutyrate (PHB), the most commonly produced PHAs. PHAs have the physicochemical properties which are quite comparable to petroleum based plastics, but PHB being homopolymers are quite brittle, less elastic and have thermal properties which are not suitable for processing them into sturdy products. These properties, including melting point (Tm), glass transition temperature (Tg), elastic modulus, tensile strength, elongation etc. can be improved by varying the monomeric composition and molecular weight. These enhanced characteristics can be achieved by modifications in the types of substrates, feeding strategies, culture conditions and/or genetic manipulations. 相似文献
72.
G.M. Massanet I.González Collado F.A. Macías F.Rodríguez Luis C. Vergara 《Phytochemistry》1984,23(4):912-913
Integrifolin, the major constituent of Andryala integrifolia, has been isolated and characterized as 3β,8β-dihydroxy-4(15),10(14),11(13)-trien-(1αH), (5αH) guaian-6,12-olide (8-epi-desacylcynaropicrin). 相似文献
73.
Ferdinand Bohlmann Christa Zdero Robert M. King Harold Robinson 《Phytochemistry》1984,23(7):1509-1511
A reinvestigation of the aerial parts of Conocliniopsis prasiifolia afforded two furoheliangolides, conoprasiolide-9-O,5′-O-diacetate and 相似文献
74.
Ferdinand Bohlmann Kazuyasu Umemoto Jasmin Jakupovic Robert M. King Harold Robinson 《Phytochemistry》1984,23(8):1669-1672
The investigation of two Ferreyanthus species afforded seven germacranolides which have not been isolated previously. Two derivatives of linalol were also present. The structures were elucidated by spectroscopic methods. Chemotaxonomic relationships are briefly discussed. 相似文献
75.
76.
Nezhun Gören Ayhan Ulubelen Jasmin Jakupovic Ferdinand Bohlmann Michael Grenz 《Phytochemistry》1984,23(10):2281-2284
In addition to known compounds an investigation of the fruits of Smyrnium rotundifolium afforded four new germacrane derivatives, all closely related to glechomanolide, one being a secogermacrane anhydride. The new compounds were 8,9-epoxy-8,9-secoglechomanolide, 1β,10α-epoxy-4-methoxy-8-hydroxyglechomanolide and 8-oxo-8,9-secoglechomanolide. The structures were assigned by spectral methods as well as by some chemical reactions. 相似文献
77.
Reinvestigation of the aerial parts of Pluchea dioscoridis afforded, in addition to known compounds, five new eudesmanolides and a new thiophene derivative. The stereochemistry of one of the eudesmanolides isolated previously has been corrected. The structures were elucidated by spectroscopic methods. 相似文献
78.
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80.
A number of polyketide synthase gene sequences fromAspergillus ochraceus were isolated by both SSH-PCR and degenerate PCR. The deduced amino acid sequences of the corresponding clonedpks DNA fragments were then aligned with the amino acid sequences of other polyketide synthase enzymes. One of thesepks genes is essential for ochratoxin A biosynthesis (OTA-PKS). The OTA-PKS was most similar to methylsalicylic acid synthase
(MSAS) type PKS proteins based on the alignment of the ketosynthase domains while if the acyl transferase domains were aligned
it appeared to be more similar to PKS enzymes fromCochliobolus heterostrophus. The three PKS proteins identified by degenerate PCR were all from different PKS types, one was a MSAS type enzyme, the second
was similar to the PKS proteins involved in lovastatin biosynthesis while the third was not similar to any of the other phylogenetic
groupings. Data is presented which suggests that the use of phylogenetic analysis to predict the function of PKS proteins/genes
is likely to be significantly enhanced by analyzing more than one domain of the protein.
Presented at the EU-USA Bilateral Workshop on Toxigenic Fungi & Mycotoxins, New Orleans, USA, July 5–7, 2005
Financial support: Irish Government under the National Development Plan 2000–2006 相似文献