Phytochemical yield

Particle size. Phytochemical yield increased with decreased particle size, and therefore nuts and seeds are generally ground to small particles to increase the surface area... 

Such irrformation is imperative in maximizing phytochemical yield. 

Moisture. Moisture had different effects on the extraction yield of phytochemicals. For example, the a- and (3-carotene extraction yields using SC-CO2 increased from 184 to 599 pg/g dry carrot and from 354 to 892 pg/g, respectively, with decreasing the moisture in the feed material from 84.6 to 0.8%. The lutein yield decreased from 55.3 to 13 pg/g dry carrot with a decrease in moisture from 84.6 to 0.8% (Sun and Temelli 2006). For the extraction of lycopene from tomato with 50-60% moisture content, only trace amounts of lycopene were reported (Vasapollo and others 2004). 

Flow rate and extraction time. No report was found for the effect of flow rate in the extraction of phytochemicals from herbs. Extractions at lower pressures and/or temperatures required prolonged time and large amounts of CO2 to achieve the same yield as reported for the extraction of caffeine, theophylline, and theobromine from mate tea leaves (Saldana and others 1999,2002a). 

Preparation and phytochemical reduction of 2,2 -thenoin and 2,2 -thenil have been studied in the authors laboratory (20a). It has been shown that 2,2 -thenoin gives a color reaction similar to that shown by benzoin and other acyloin condensation products in- the presence of alcoholic alkali. The hydroxy ketone may be oxidized by iodine in the presence of sodium methoxide to give the diketone, 2,2 -thenil, in excellent yields. Phytochemical reduction was shown also to be applicable to both compounds. It is significant that thenoin differs from benzoin, since reduction products were not obtained enzymatically from the latter. 

Abstract Recent chemical studies on the marine soft corals and terrestrial plants have lesnlted in the isolation of several novel componnds. The soft corals, Pseudopterogorgia elisabethae and Cladiella species yielded several novel terpenoids, exhibiting antimicrobial activities. New steroids were isolated from terrestrial fungi, Mucor plumbeus and Coprims micaceus. Phytochemical studies on the Buxus hyrcana, collected from Iran, have yielded steroidal bases. This revdew describes the new natiual products exhibiting different bioactivities from the aforementioned sources. 

Similarly, methyl a-chloroethyl ketone, a, -dichloroacetone and a,a,/3-trichlorobutyraldehyde have been converted phytochemically and in good yield to the corresponding primary or secondary halogenated alcohols. Since all these alcohols show optical rotation, it seems established that the phytochemical reduction generally takes an asymmetric course. (See pp. 80, 81, 88 and 92.)... 

The phytochemical reducibility of quinones was first demonstrated in the case of p-xyloquinone. This compound is worthy of interest since it is very easily formed from diacetyl by purely chemical means through a type of aldol condensation followed by ring closure. It is reduced to p-xylohydroquinone by fermenting yeast. Benzoquinone, thymoquinone and a-naphthoquinone similarly yield the corresponding hydroquinones. Tetrabromo-o-quinone and anthraquinone proved resistant to attack, while phenanthraquinone could be reduced phyto-chemically to phenanthrahydroquinone in poor yield (9%). Phytochemical reduction can also be accomplished in the dicyclic terpene series. According to unpublished experiments by Neuberg and Peiser, 2,3-dihy-... 

The previously discussed reductions by yeast of isovaleraldehyde to isoamyl alcohol, of p-xyloquinone to p-xylohydroquinone and of sodium thiosulfate to hydrogen sulfide have also been accomplished with Bacterium coli and Bacterium lactis aerogenes. Phytochemical reduction of d,l-valeraldehyde (methylethylacetaldehyde) with Termobacterium mobile Lindner Pseudomonas Lindneri) takes a practically quantitative course and yields an amyl alcohol containing 17 % excess of the dextrorotatory component. Cahill achieved especially favorable results by the reduction of isovaleraldehyde with growing bacteria instead of with their mass cultures. 

Hamburger, M., Baumann, D., and Adler, S., Supercritical carbon dioxide extraction of selected medicinal plants — effects of high pressure and added ethanol on yield of extracted substances, Phytochem. Anal., 15, 46, 2004. 

Licania heteromorpha var. heteromorpha Bentham is a tree up to 30 m high native to the Amazonian forest. Phytochemical study of its aerial parts yielded both triterpenes and flavonoids triterpenes were obtained from the chloroform extract by silica gel column followed by RP-HPLC and were characterised as betulinic acid (11), alphitolic acid (48), 3(3-0-trans-p-coumaroyl alphitolic acid (49), 3(3-0-cw-p-coumaroyl alphitolic acid (50), 3 -0-trans-p-coumaroyl maslinic acid (51), 3fi-O-cis-p-coumaroyl maslinic acid (52), 3(3-0-tnms,-/ -coumaroyl-2a-hydroxy-urs-12-en-28-oic acid (53), 3 3-0-m-p-coumaroyl-2a-hydroxy-urs-12-en-28-oic acid (54) [see Fig. (2) and (6)] [15], Compounds 11 and 48-54 were identified comparing their H and 13C NMR data with those previously described. Triterpenoids 48-54 were found for the first time in Licania, while betulinic acid had been isolated previously from L. carii [9]. On the other hand, flavonoids were isolated from the chloroform-methanol and methanol residues by Sephadex LH-20 and HPLC they were identified as myricetin 3-0- 3-D-galactopyranoside (17), myricetin 3-0-a-L-rhamnopyranoside (32), myricetin 4 -methylether-3-0- 3-D-glucopyranoside (55), myricetin 4 -methylether-3-0-a-L-rhamnopyranoside (45), myricetin 3,4 -di-0-a-L-rhamnopyranoside (56), myricetin 7-methylether 3,4 -di-0-a-L-rhamnopyranoside (57), and myricetin 4 -methylether-3-0- 3-D-galactopyranoside (58) [see Fig. (2), (4), and (6)]. The last three myricetin derivatives were new natural compounds [16]. Known compounds were identified by comparison of their H and l3C NMR spectra with those reported in the literature [15]. 

In the Orient, numerous natural products have long been used in folk medicine. Also, in recent years some pharmaceutical industries and universities in Korea are placing their efforts on the quantification of cytotoxic phytochemicals from the natural resources. As a part of those efforts, the present authors are involved on the two-fold critical evaluations of the possible implementation of the supercritical fluid extraction(SFE) to obtain extracts from the natural resources one is the establishment of the optimum SFE condition for each sample resource which gives maximum extraction yield and cytotoxicity, and the other is the high-purity isolation of some specific compounds from the SFE total extracts. 

Coumarinolignans are not restricted to any particular plant family or genus and, in fact, are rather widely distributed. Some 44 plant species belonging to 19 different plant families have so far been known to produce this group of phytochemicals. The various sources known so far to yield coumarinolignans are listed in Table 1. 

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