There are various kind of natural resources around us, and they must contain a lot of unknown bioactive substances. Some may be structurally very strange for us, and some are very familiar. But their biological activity was not unfortunately investigated in detail. Accordingly, exploring new types of pharmaceutical resources may give lead compounds of the drugs in the future. Among those natural resources, I examined squid ink and scallop soup. From squid ink, an antitumor glycoconjugate was obtained. Its polysaccharide moieties, illexin A, illexin B and illexin C, were isolated, and the spectral data and chemical transformation of their acid hydrolysate revealed to bear a unique branched repeating unit, [-3GlcAβ1-4(GalNAcα1-3)Fucαl-]n. Moreover, scallop soup gave antitumor glycogen by the action of protease. The fine structure of glycogen was investigated by the sequential enzyme digestion method using β-amylase and pullulanase, while the unit chain was analyzed by high performance anion exchange chromatography. The results showed that the antitumor active glycogen was highly branched with shorter chain than glycogens without antitumor activity.
The development of modified Pd catalysts for chemoselective hydrogenation has been a long-standing goal in synthetic chemistry. Several applications of catalyst poisons for this purpose have been studied. But these methods usually lack rules of generality except for a few examples such as Lindlar catalyst and Rosenmund's reaction. Recently, we found that the addition of a nitrogen containing base such as ammonia, triethylamine, pyridine, ammonium acetate, to a Pd/C-catalyzed reduction system selectively inhibited the hydrogenolysis of an aliphatic benzyl ether with smooth hydrogenation of other reducible functions such as olefin, N-Cbz, benzyl ester and azido. However, the selective suppression of hydrogenolysis was not applicable to the benzyl protective group with phenolic hydroxyl functions. The problem has been temporarily solved by the employment of a 4-methoxybenzyl (MPM) protective group instead of the more reducible benzyl group with phenolic hydroxyl functions. During the course of our further study on the Pd/C-catalyzed chemoselective hydrogenolysis, we further found large differences in the suppressive effect on the hydrogenolysis of O-benzyl protective groups depending upon the nitrogen-containing bases employed as additives. By the use of Pd/C-2, 2'-dipyridyl combination as a catalyst for the hydrogenation, aliphatic and phenolic O-benzyl protective groups can be retained without any hydrogenolysis. Further-more, we found that the Pd/C catalyst formed an isolable complex with ethylenediamine employed as a catalytic poison, selectively catalyzing the hydrogenation of various functional groups without hydrogenolysis of O-benzyl protective groups even in phenolic benzyl ethers.
Some hexagonal mesporous silicas were attempted to use as a promoter for fine organic synthesis. Ti-HMS, a Ti-loaded hexagonal mesoporous silica, which possesses Lewis acid sites due to Ti-atom, was found to accelerate deprotection of benzyl ethers under hydrogenolytic conditions with palladium catalyst. Such acid-sensitive functional groups as silyl ether and acetal moieties in the molecule were little affected by Ti-HMS. MCM-41, a hexagonal mesoporous silica, /MeOH heterogeneous system was found to remove selectively and easily triethylsilyl (TES) group of silyl ethers of several types in the presence of t-butyldimethylsilyl (TBS) group. FSM-16, another hexagonal mesoporous silica, was found to catalyze oxidative photodecarboxylation of α-hydroxy carboxylic acid and phenyl acetic acid derivatives to afford the corresponding carbonyl compounds. Furthermore, FSM-16 proved to be reuseable by recalcination at 450°C after the reaction. Efficiency of these reactions was investigated concerning the solvent effect and activities of the promoters including common zeolites and ion-exchange resins.
This article reviews for our two kinds of projects that lipase-catalyzed asymmetric resolution of bicyclic lactams, 3-oxo-2-azabicyclo[2.2.0]hex-5-enes and 2-azabicyclo[2.2.1]hept-5-en-3-ones, possessing synthetic versatility and the development of a new type of a bicyclic amine-based chiral ligand for a catalytic asymmetric synthesis. Thus, optically active 3-oxo-2-azabicyclo[2.2.0]hex- and 3-oxo-2-azabicyclo[2.2.1]hept-5-enes were obtained conveniently by lipase-catalyzed enantioselective acylation or hydrolysis of racemates, and absolute configurations were determined by chemical correlation, X-ray crystallographic and CD spectral analyses. Furthermore, optically active 2-azanorbornylmethanols, isoquinuclidinylmethanols, 2-azanorbornylmethanethiol, and isoquinuclidinylmethanethiol were prepared from ethyl(1S, 3S, 4R)-2-[(R)-1-phenylethyl]-2-azabicyclo[2.2.1]hept-5-ene-3-carboxylate easily and their abilities as ligands were examined in the addition of diethylzinc to aldehydes to furnish secondary alcohols up to>99% ee. Particularly, 2-azanorbornylmethanethiol was the most effective as ligand in the alkylation.
This review summarizes our recent findings in the syntheses of drug metabolites. The metabolites of Grepafloxacin (1) and OPC-14117 (10) were prepared from the common intermediates (5) and (21), respectively. Moreover, treatment of 10 with a model P450 system led to a benzyl alcohol derivative (11) in one step. OPC-31260 (22) was efficiently N-dealkylated using several metalloporphyrins with oxidants to afford three metabolites (23-25). In addition, I succeeded in obtaining the metabolite (23) in high yield from N-oxide (26) not only as an oxygen donor but also as a substrate, there after, in the model P450 system. Optically active metabolites of OPC-29030 (27) were prepared by enzyme-catalyzed enantioselective transesterification of racemic sulfinyl metabolites. On the other hand, a chiral 1, 1'-bi-2-naphthol derivative (38a) was found to be an efficient asymmetric acylating agent for a secondary alcohol (36) which is a valuable intermediate for preparing optically active metabolites of 22. Furthermore, metabolites (45) and (47) of OPC-21268 (44) were prepared using SmI2-induced cyclization and oxidative decarboxylation with Pb(OAc)4 as key steps, respectively.
Vibrio vulnificus is an opportunistic human pathogen causing wound infection and septicemia, characterized by hemorrhagic and edematous damage to the skin of limbs. When injected into the dorsal skin, an extracellular metalloprotease from this vibrio (V.vulnificus protease : VVP) enhanced the vascular permeability through activation of the Hageman factor-plasma kallikrein-kinin cascade and/or stimulation of exocytotic histamine release. Additionally, VVP caused the hemorrhagic skin lesion through disorganization of the vascular basement membrane layer due to specific degradation of type IV collagen, which is known to form the backbone structure of the basement membrane. However, injected VVP was quickly inactivated by a plasma glycoprotein, α-macroglobulin, at a molar ratio of 1 : 1. This glycoprotein was leaked from the capillaries by the actions of VVP, which resulted in in situ inactivation by physical entrapment. When VVP (45000 Da) was incubated at 37°C, a 35000 Da fragment was generated by the autocatalytic removal of a 10000 Da C-terminal polypeptide. This N-terminal fragment showed significant proteolytic activity, however, because of a markedly decreased affinity to the protein substrates, its permeability-enhancing and hemorrhagic activity was reduced to less than 50%. These findings indicate that the C-terminal polypeptide is not essential for but promotes skin reactions caused by VVP.
Oligodeoxyribonucleotides containing a DNA lesion were synthesized and inserted into vector DNAs to introduce the lesion at a predetermined site. The manipulated DNAs were transfected into living mammalian cells and The mutants induced by the DNA lesion were collected and analyzed. This approach was applied to various DNA lesions produced in cells by reactive oxygen species, chemicals, and ultraviolet light. In addition, the mutations induced by damaged DNA precursors were studied by the use of chemically synthesized nucleoside triphosphates. In this review article, the author summarizes the results obtained by these types of experiments, focusing on two oxidatively damaged compounds, 8-hydroxyguanine (7, 8-dihydro-8-oxoguanine) and 2-hydroxyadenine (1, 2-dihydro-2-oxoadenine).
We developed chitin-containing cisplatin (CDDP) albumin microspheres(MS). We also investigated physical properties of MS in vitro, anti-tumor effect of MS in VX2 tumor model rabbits in vivo and clinical evaluation of MS. The CDDP contents, specific surface areas and yield of MS increased with an increase in the concentration of chitin. These findings suggest that accumulation of chitin on the surface of microsphere was the cause of expansion of the coated area as the concentration of chitin increased. In vitro CDDP releases decreased as the concentration of chitin increased. The initial burst effect of the drug was to be controlled by the increase of concentration of chitin. The chitincontaining CDDP microspheres showed similar CDDP release patterns irrespective of the concentration of chitin between 1 and 6h after the administration of CDDP microspheres. After 6h, the blood Pt levels increased with an increase in the concentration of CDDP microspheres suggesting a significant effect of the concentration of chitin on microsphere decomposability in vivo. Tumor growth rate was increasingly suppressed as the concentration of chitin increased. Clinical findings indicated that antitumor activity of chitin-containing CDDP albumin microspheres would have a chemoembolic effect by embolizing the hepatic artery. In the tumor and necrosis portions phagocytosis of microspheres by macrophage-like giant cell was shown. Consequently, the biocompatibility and decomposable properties of chitin-containing CDDP albumin microspheres were demonstrated.
This study was conducted to evaluate pharmacy services to patients or customers with prescriptions issued by large hospitals. The primary purpose of this study is to assess patients' perceptions and expectations of pharmacy services with a view to standardizing community pharmacies for better health care. Two groups of patients or pharmacy patrons were evaluated, i.e. those who utilized pharmacies adjacent to the hospitals (Group A) and those who utilized other community pharmacies (Group B). The survey consisted of 26 evaluation functions ranging from location to services. Based on these functions, patients were requested to use a scale of 1 to 5 to rate the pharmacy they are currently using ("Pharmacy Used Today") and their perception of an "Ideal Pharmacy". These evaluation functions were analyzed and classified into seven dimensions which formed the evaluation index used in this study. These are : (1) availability of over-the-counter drugs, (2) availability of special services such as delivery of medicines, acceptance of fax order, etc., (3) facilities, (4) convenient location, (5) attitude of pharmacy/pharmacist, (6)information management, and (7) convenient hours. In comparing the results of the study, it was revealed that both groups of patients/pharmacy patrons have common expectations or perceptions as to what is an "Ideal Pharmacy". The results also revealed that of the seven dimensions mentioned above, the three most important to patients/patrons are : attitude of pharmacy/pharmacist, convenient hours, and information management. In rating the "Pharmacy Used Today", Group A patrons gave lower ratings than Group B patrons in all dimensions except facilities. The variance between the "Pharmacy Used Today" and the "Ideal Pharmacy" is greater in Group A than in Group B. The results of this investigation indicate that the Group B patients/patrons have received greater amount of benefits of the "Bungyo" than Group A ones, although the fact is that most outpatients use pharmacies located adjacent to hospitals in order to obtain their medications.
In the course of a review of the current health insurance system in Japan, promotion of the use of generic products of lower price is expected in direction for minifying the drug costs which occupy about 20% thereof. However, the use of generic products has not increased so much as expected. One of the reasons to explain the fact might be that concerns exist about switchability from an innovator product to a generic product or among generic products because of bias in bioequivalence. Namely, hesitation about the difference in quality between generic products and innovator products, particularly in bioequivalence due to differences in the manufacturing process and pharmaceutical technology, exists among professionals in medical practice. The bioequivalence study to guarantee that a generic product is bioequivalent to an innovator product in terms of effectiveness and safety is most important in assuring the quality of generic products. There are various specifications and study methods to prove bioequivalence which differ slightly from one to another in different countries. We have investigated bioequivalence studies which are conducted in the major countries. Consequently, we clarified that bioequivalence studies are in international harmonization in terms of the major portions thereof. However, different conditions, e.g., selection of subjects, food effect, application of multiple dose study, and in vitro dissolution study, are still employed for the studies. Therefore, we consider that these differences constitute the topics to be reviewed in future.
The bioequivalence study which is currently conducted in different countries is the so-called average bioequivalence approach; this approach has been indicated to be insufficient for assessing switchability between two formulations (i.e., from the reference formulation to the test formulation). In the U.S., therefore, the population bioequivalence approach and the individual bioequivalence approach were recently proposed as the studies which would replace the current average bioequivalence approach. The average bioequivalence approach compares only the mean parameters of the test and reference formulations in the subject groups which received them. In contrast, the population bioequivalence approach guarantees prescribability by assessing the total variances of bioavailability values of the test and reference formulations in addition to the average bioequivalence. The individual bioequivalence approach guarantees switchability from the reference formulation to the test formulation by assessing the intrasubject variance and subject-by-formulation interaction in addition to the average bioequivalence. We introduce the individual bioequivalence approach and the population bioequivalence approach in comparison with the current average bioequivalence approach and have discussed the characteristics and issues of each of these three bioequivalence approaches.
The pharmaceutical utility of the allopurinol gel (APNgel) which consists of allopurinol (APN), carrageenan (κ-CG or ι-CG) and polyethylene (oxide) (Alkox[○!R]) was investigated as a possible material for an oral dosage preparation for ease in handling and/or swallowing. The gel formation was studied as a function of a variety of the concentration of Alkox[○!R] and/or CG added. The APNgel gelled with κ-CG was not appropriate to the oral dosage form because of its original taste and odor. In contrast, since ι-CG has no odor and/or taste, we added ι-CG as a gel material. From the investigation of the gelation behavior and the handling of the gelled material, the preferred composition of APNgel (Alkox[○!R] : ι-CG% ratio) seemed to be that of 0.5 : 2.0, 1.0 : 2.0 and 2.0 : 2.0. The gel strength and the in vitro assessment of the adhesiveness of APNgels were evaluated using a creep meter. The gel strength of the APNgel was affected by the amount of the added Alkox[○!R]. From the in vitro assessment of the adhesiveness of APNgels, the adhesiveness of APNgel increased with an increase in the amount of added Alkox[○!R]. The release behavior of APN from APNgels was investigated by the paddle bead method, mimicking the chewing action in mouth. The APNgel was sheared by the beads and the release of APN completed within 480 s. From the results of the sensory test, APNgel consising of 2.0% ι-CG and 1.0% Alkox[○!R] seemed to be favorite to the jelly-like preparation.
To examine the influence on the quality of toad venom processed by different drying methods, each 10 g sample of fresh toad venom collected in Shang-Dong Province, China, were dried, (1) in the sun for 133 h, (2) in the shade for 224 h, (3) heated at 60°C for 33 h, (4) heated at 105°C for 4 h, (5) freeze-dried for 6 h. Twelve bufadienolides, including bufalin and bufotalin, in each sample were then quantitatively analyzed by HPLC. The total contents of bufadienolides in 1000 mg of the dried samples were as follows : 235.39 mg for dehydrolyzed fresh toad venom, 94.39 mg for (1), 148.46 mg for (2), 59.22 mg for (3), 133.40 mg for (4), and 184.77 mg for (5), respectively. The color of dried venom became darker in the order of (5), (2), (1), (3) and (4). Though the color of (4) should be the worst as a standard quality evaluation in Shang-Dong Province, as far as bufadienolides was concerned, (4) was superior to (1) in the contents and was almost same to (2). These results suggest that it is possible to dry toad venom by heating at high temperature for several hours. This will remarkably shorten the term for making high quality toad venom, in comparison to the traditional processing method in China that needed more than two years for drying venom.
Clove buds oil is one of very important natural essential oil with a typical spicy note and also known as a source of eugenol. These phenol compounds, which have the strong perfume of clove, are widely used not only as an analgesic and antiseptic agent in dentistry. However, the problem is that the phenol compounds caused sensitization on the skin occasionally. We reported that the skin sensitization by eugenol and its derivatives was detected in the guinea pig maximization test (GPMT) and also confirmed that dehydrodi-eugenol, a biphenyl compound of eugenol, did not show the skin sensitization. To discuss more, we examined the skin sensitization by several phenol compounds and its biphenyl ones. Consequently, we confirmed that the skin sensitization by biphenyl compounds more remarkably decreased than that by phenol compounds (monomer).
New guidelines for the clinical use of blood preparations, intended to promote a more rational use, were issued by the Japanese Ministry of Health and Welfare in June 1999. The purpose of this article is to clarify the current situation in the non-surgical use of albumin (Alb) preparations in each clinic division and to design a plan to promote the rational use of these products at Yamaguchi University Hospital. Of the patients administered Alb preparations in the clinic divisions of our hospital over the six-month period from January 1 to June 30, 1999, 454 were selected based on prescription records of plasma component preparations. Most of the patients were 60 years of age or older (61.7%) and from the surgery division(65.2%). The total amount of Alb administered to the patients was 52.9kg. Those patients whose serum Alb concentration was less than 2.5g/dl before and more than 3.5g/dl after the administration numbered 125 and 122, respectively. The total amount of Alb overdosed to the patients, whose Alb concentration after administration of the preparations was more than 2.5g/dl, was 17.7kg (33.5% of the administered amount). The overdosed patients belonged mainly to the surgery division. These results indicate that it is possible to cut back on Alb by reconsidering the criteria for its administration, and that we need to promote more intensively the need to monitor the level and predict the effect of Alb in surgical divisions.