Seven kinds of hydroxycinnamic acid derivatives identified as 3-caffeoylquinic acid (3-CQA), 4-caffeolyquinic acid (4-CQA), 5-caffeoylquinic acid (5-CQA), 5-feruloylquinic acid (5-FQA), 3,4-dicaffeoylquinic acid (3,4-diCQA), 3,5-dicaffeoylquinic acid (3,5-diCQA), and 4,5-dicaffoylquinic acid (4,5-diCQA) by MS, 1H NMR, and HPLC analyses were isolated from low-quality (immature) and commercial quality green coffee beans. The quantity of chlorogenic acid isomers (10.4 g/100 g), especially 5-CQA, in commercial green coffee beans [West Indische Bereiding (West India processing beans from Sumatra Island, Indonesia, WIB)] was higher than that in low-quality beans [9.1 g/100 g, Eerste Kwaliteit (Export low-quality beans from Java Island, Indonesia, EK-1, grade 4)], whereas little difference in diCQAs was detected between the two kinds of beans. The free radical scavenging activity of these isolates was evaluated in assay systems using DPPH free radicals and superoxide anion radicals generated by xanthine-XOD. The diCQAs showed strong (1.0-1.8-fold) free radical scavenging activity compared to commonly used antioxidants such as alpha-tocopherol and ascorbic acid. The potency order of superoxide anion radical scavenging activity was diCQAs > caffeic acid, CQAs > 5-FQA. The activities of the diCQAs were twice as effective as those of CQAs and 4 times as effective as that of 5-FQA. The diCQAs also exhibited more potent (2.0-2.2-fold) tyrosinase inhibitory activities compared to CQAs, arbutin, and ascorbic acid. The isolates exhibited antiproliferation activities in four cancer cell lines, U937, KB, MCF7, and WI38-VA. Among these, KB cells were most sensitive (IC50 = 0.10-0.56 mM).

We assayed in vitro the biological activities of caffeic acid phenethyl esters that had been enzymatically synthesized from 5-chlorogenic acid and phenethyl alcohol. Caffeic acid phenethyl esters showed antioxidant and hyaluronidase-inhibitory activities similar to those of chlorogenic acid and caffeic acid, and markedly higher antibacterial, antimutagenic, and antiviral activities than chlorogenic acid. The antimicrobial activities of caffeic acid phenylethyl esters against Staphylococcus aureus, Bacillus subtiiis, and Pseudomonas aeruginosa (MIC; 0.22-0.44, 0.44-0.88, and 0.44-0.88 mM, respectively) were higher than those of 5-chlorogenic acid and caffeic acid. 2-Caffeic acid phenylethyl ester showed potent antimutagenic activity against quinoline compounds, aromatic amines, and heterocyclic compounds. In addition, 2-caffeic acid phenylethyl ester at concentrations of less than 35 uM promoted the proliferation of normal human pulmonary fibroblasts (WI-38 cells) in culture, but inhibited the proliferation of virus-transformed fibroblasts (WI-38 VA cells; IC50 of 60 uM). 1and 2-Caffeic acid phenylethyl esters at a concentration of 8.8 uM inhibited the growth of type A influenza virus by 95% and 96%, respectively, and that of type B influenza virus by 92% and 94%, respectively. These results indicate that caffeic acid phenylethyl esters have higher antimutagenic and anti-influenza virus activities than chlorogenic acid and caffeic acid.

A chlorogenate hydrolase (EC 3.1.1.42) synthesized 2-phenylethyl caffeate (2-CAPE) from 5-chlorogenic acid (5-CQA) and 2-phenylethyl alcohol (2-PA) (by transesterification), from 5-CQA and 2-phenylethyl bromide (2-PBr) (by substitution of bromine), and from caffeic acid (CA) and 2-PA or 2-PBr (by condensation) as well as hydrolysis of 5-CQA. Some reaction conditions including pH, temperature, substrate and solvent concentrates, and reaction time were optimized for the production of 2-CAPE. A maximal molar yield of 50% was achieved by transesterification, 4.7% by substitution of bromine, and 13% by condensation. Among the parameters studied for optimization, the pH of the buffer solution and concentration of 2-PA or 2-PBr affected the production of 2-CAPE. The optimum pH for the hydrolysis reaction was within the neutral range (pH 6.5), whereas the residual three reactions were only catalyzed within the acidic range (pH 3.0-4.0). The optimum concentrations of 2-PA and 2-PBr for three reactions were 5-70 vol% and no 2-CAPE was produced in the 2-PA or 2-PBr solutions containing powdered enzyme. The enzyme may bind to the caffeoyl moiety of 5-CQA or CA to form an enzyme-substrate complex. It then catalyzes four different reactions corresponding to the reaction conditions.

Jellies for oral administration are dosage forms that contain water, as stipulated in the Japanese Pharmacopeia, and heat is generally applied to the jellies during the manufacturing process. Therefore, it is difficult to formulate drugs that may be affected adversely by water and/or heat. To solve this problem, we tried to develop a powder form of gel as a novel dosage form (dry jelly: jelly medicine extemporaneously prepared) that is converted to jelly after addition of water at the time of administration. For this purpose, a basic gel formulation consisting of pectin, glucono-δ-lactone, dibasic calcium phosphate hydrate, and sucrose was investigated to evaluate the critical factors affecting gelation phenomena. The gel form was developed by adjusting the amount of each component of the formulation and of water added. Gelation occurred even with hard water containing metal ions (hardness of approximately 304 mg/L), and no changes in gel hardness occurred. The desired gel hardness could be controlled by adjusting the amount of water. The gel hardness changed over time after the addition of water, but this change did not affect the dissolution behavior of drugs formulated in the dry jelly.