We describe the synthesis and results of biological evaluation of newly designed 2,4,6-trisubstituted symmetrical 1,3,5-triazine (TAZ) derivatives. Among the tested trisubstituted TAZ derivatives, some C Ssymmetrical alkoxy-amino-substituted TAZ derivatives, including 7ggp and 6dpp, showed significant antiviral activity against herpes simplex virus type 1 (HSV-1). The compound with the highest level of antiviral activity was C 3 -symmetrical trialkoxy-TAZ derivative 4bbb, which showed a considerably high selectivity index (IC 50 /EC 50 256.6). The structure-activity relationships for anti-HSV-1 activity of the tested 2,4,6-trisubstituted TAZ derivatives are also described.Key words 1,3,5-triazine; anti-herpes simplex virus type 1; cytotoxic activity; C S symmetry; C 3 symmetry; plaque reduction assay Supramolecular interaction of two-fold (C 2 ) or three-fold (C 3 ) symmetrical geometry macromolecules with many bioactive compounds is one of the common features of many important biological processes, [1][2][3] and small molecules having C 3 -, C S -, or C 2 -symmetrical geometry often appear in various biologically active compounds contrasted on a symmetrical template. [4][5][6] We have therefore expected that such small symmetrical molecules would be promising new candidates or leads in the search for biologically active compounds that interfere with the sugar recognition process in a controlled biological response. From this aspect of molecular symmetry, we have already reported a few examples of such types of new symmetrical molecules for the purpose of finding new biological active compounds. 7-9)We have recently reported some molecular modifications of 2,4,6-trichloro-1,3,5-triazine (TCTAZ) to C 3 -, or C Ssymmetrical trisubstituted TAZ molecules and the results of biological evaluation of synthesized symmetrical 2,4,6-trisubstituted TAZ derivatives. 7) Among previously targeted TAZ derivatives, some alkoxy-amino-substituted derivatives showed significant anti-herpes simplex virus type 1 (HSV-1) activities. The previous analysis of anti-HSV-1 active molecular features indicated that a C S -symmetrical TAZ derivative with two alkoxy groups and one amine moiety seemed to be a required structure for preferred anti-HSV-1 activity with a good selectivity index.For an extension of our study, we examined further modifications of this symmetrical class of compounds in order to investigate the structure-activity relationship (SAR) of alkoxyamino-substituted TAZ molecules as well as their biological evaluation. In this paper, we report the results of preparation of newly targeted C S -symmetrical TAZ derivatives together with the results of biological evaluation of obtained symmetrical 2,4,6-trisubstituted TAZ derivatives.Chemistry In our previous article, 7) we reported that synthesis of target alkoxy-amino-trisubstituted TAZ derivatives is easily achieved by a procedure via alkoxy-substituted chloro-TAZ intermediates starting from TCTAZ (1). This procedure consists of two-stage nucleophilic substitutions of compound...

We report the preparation of new C- and C-symmetrical molecules constructed on a triazine (TAZ) template. Anti-herpes simplex virus type 1 (anti-HSV-1) and cytotoxic activities against Vero cells of synthesized TAZ derivatives were evaluated. The results suggested that the presence of an electron-donating group(s) on the benzene ring in benzylamine groups on the TAZ template is an important structural factor for expressing a high level of anti-HSV-1 activity and low cytotoxicity for these C types of TAZ derivatives. Among the tested TAZ derivatives, compounds 4f and 7h showed the highest anti HSV-1 activities (EC=0.98 and 1.23 µM, respectively) and low cytotoxic activities to Vero cells (50% cytotoxic concentration (CC)=292.2 and >200 µM, respectively).

It has been shown that commercial tomato juice packaged in 900 g plastic bottles contains rare, naturally occurring steroidal solanocapsine-type tomato glycosides in which the saponins consist of esculeosides B-1 (2) and B-2 (3) in 0.041% as major components lacking esculeoside A. We suggest that these saponins are derived from esculeoside A (1) when the juice in plastic bottles is prepared by treatment with boiling water, similar to the process used in preparing canned tomatoes. Herein, the obtained tomato saponins (2) and (3) provided sapogenols esculeogenin B 1 (4) and B 2 (5), respectively, by acid hydrolysis. The former was identical to esculeogenin B previously reported, and the latter was a new sapogenol characterized to be (5α,22S,23S,25S)-22,26-epimino-16β,23-epoxy-3β,23,27-trihydroxycholestane.

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In terms of molecular symmetry and bioactivity, new C 3 -and C S -symmetrical derivatives based on the tris(2-aminoethyl)amine scaffold were designed and synthesized. The synthesized compounds were evaluated for antiviral activity with herpes simplex virus type 1 (HSV-1) by a plaque reduction assay and for cytotoxic activity with Vero cells. Most of the compounds showed no significant anti-HSV-1 activity, but some of the symmetrical derivatives showed high levels of cytotoxic activitiy.Key words tris(2-aminoethyl)amine; tripodal; anti-herpes simplex virus type 1; C 3 symmetry; C S symmetry; plaque reduction assay There have been many reports on the molecular recognition properties of symmetrical molecules, 1) and it is known that the symmetrical feature is frequently observed in many biological stages. Two-fold and three-fold symmetrical macromolecular structures are common features in specialized biological functions.2-4) Regarding the molecular symmetry, small symmetrical molecules with a C 2 -symmetrical or C 3 -symmetrical structure have often been found in various synthetic biologically active compounds. 5-7)In the course of our work on new antiviral compounds, we have presented a new class of antiviral candidates. For example, we have already reported that most of the triarylmethane derivatives showed a wide range of antiviral activities against herpes simplex virus type 1 (HSV-1). 8,9) In continuation with our work for finding potent antiviral derivatives, synthetic molecular modifications directed our attention to the molecular symmetry for the biological activity. Our recent studies on heteroaryl-substituted triarylmethane derivatives indicated that compounds bearing a prochiral symmetric feature (possessing C S symmetry) showed a higher level of antiviral activity than that of the corresponding C 3 -symmetrical molecules 9,10)

As one of our projects, we here report some new molecular modifications of 2,4,6-trichloro-1,3,5-triazine (TCTAZ: 1) to symmetrical 2,4,6-trialkoxy-or 2,4,6-triaryloxy-substituted 1,3,5-triazine (TAZ) molecules, as well as the results of anti-herpes simplex virus type 1 (anti-HSV-1) activity evaluation of synthesized 2,4,6-trisubstituted TAZ derivatives. Among the tested 2,4,6-trisubstituted TAZ derivatives, we reconfirmed that a C 3 -symmetrical TAZ derivative, 4e, shows the highest level of anti-HSV-1 activity with a good selectivity index. In this paper, we also report the results of the preparation of newly targeted TAZ derivatives and the structure-activity relationships (SARs) of these trialkoxy-substituted TAZ derivatives and related compounds. The sugar recognition properties of C 3 -symmetrical TAZ derivative 4e are also described.Key words 1,3,5-triazine; C 3 symmetry; anti-herpes simplex virus type 1; structure-activity relationship; plaque reduction assay; isothermal titration calorimetryThe glycocalyx at the cell surface, containing glycoproteins, proteoglycans and glicolipids, plays an important role in various cell-to-cell communications. Specific interactions of these carbohydrates with lectins (protein receptors) are important biological processes, including the processes of bacterial or viral infection and tumor metastasis. 1-3)From the viewpoint of molecular symmetry, many host receptors that consist of homo-oligometric units (homomultiligands) often construct symmetric macromolecule architectures such as C 2 -or C 3 -symmetrical geometry receptor systems. These phenomena of macromolecules connected with many biological stages have encouraged scientists to develop new multivalent symmetrical synthetic molecules to find new bioactive compounds or leads. Results of many works related to the above conception have been published over the past few decades. [4][5][6][7] The terms identical twin-drugs and tripletdrugs (symmetrical bivalent and trivalent molecules) are now commonly used in medicinal chemistry and related scientific fields. In connection with our synthetic works on such symmetrical molecules, we have already designed and synthesized a few new symmetrical molecules and evaluated their bioactivities in order to find new types of bioactive compounds. 8-17)In connection with the above projects, we have recently reported some molecular modifications of 2,4,6-trichloro-1,3,5-triazine (TCT AZ) (1) to symmetrical 2,4,6-trisubstituted 1,3,5-triazine (TAZ) molecules and the results of biological evaluation of synthesized symmetrical 2,4,6-trisubstituted TAZ derivatives. 8,9) Among previously targeted trisubstituted TAZ derivatives, we found that a C 3 -symmetrical TAZ derivative with three isopropoxy groups on a TAZ template such as compound 4e showed a high level of anti-herpes simplex virus (HSV)-1 activity and low cytotoxity, and it therefore seemed to be a potential lead in the search for preferred anti-HSV-1 activity with a good selectivity index (SI).In this paper, we report the results of...

The increasing incidence of atopic dermatitis during recent decades has prompted the development of safe and effective agents for prevention of atopic diseases. Esculeoside A, a glycoside of spirosolane type, is identified as a major component in ripe tomato fruits. The present study investigated the effects of esculeoside A and its aglycon esculeogenin A on hyaluronidase activity in vitro and antiallergy in experimental dermatitis mice. Esculeogenin A/esculeoside A (esculeogenin A equivalent) with an IC50 of about 2 μM/9 μM dose-dependently inhibited hyaluronidase activity measured by a modified Morgan-Elson method. Oral treatment with esculeoside A 10 mg/kg of experimental dermatitis mice for 4 weeks significantly decreased the skin clinical score to 2.5 without any detectable side effects compared with 6.75 of the control. The scratching frequency of esculeoside A 100 mg/kg application was decreased significantly as 107.5 times compared with 296.67 times of the control. Thus, the present study showed that esculeoside A/esculeogenin A significantly blocks hyaluronidase activity in vitro and that esculeoside A ameliorates mouse experimental dermatitis.

Italian canned tomatoes contain the tomato glycosides esculeosides B-1 (1, 0.0052%) and B-2 (2, 0.0068%) without esculeoside A. Herein, the structure of esculeoside B-1 (1) is characterized to be 3-O-β-lycotetraosyl (5S,22R,23S,25S)-22,26-epimino-16β,23-epoxy-3β,23,27-trihydroxycholestane 27-O-β-d-glucopyranoside. We hypothesized that these substances might be derived from esculeoside A when the cans are prepared with treatment in boiling water. To confirm that hypothesis, we refluxed esculeoside A with water for 6.5 h, providing esculeosides B-1 (1) and B-2 (2) in yields of 25.8% and 31.0%, respectively. Key words Solanum lycopersicum; canned tomato; tomato saponin; esculeoside A; esculeoside B-1; esculeoside B-2In 2003, Nohara and colleagues 1,2) isolated a tomato saponin, called esculeoside A, from the ripe fruits of tomato, Solanum lycopersicum L. and determined its structure ( Fig. 1). Tomato saponin is a significant component of ripened tomatoes and occurs at levels approximately 4-fold higher than those of lycopene. Thus far, the bioactivity of tomato has been attributed solely to lycopene. Therefore, carrying out pharmacological examinations of esculeoside A in the near future is important.Recently, Fujiwara et al. 3) have revealed that oral administration of esculeoside A to apolipoprotein E-deficient mice significantly reduces levels of serum cholesterol glycerides, low-density lipoprotein-cholesterol and the areas of atherosclerotic lesions without any detectable side effects. Our recent studies on the constituents of Solanum plants have revealed that pregnane glycosides are accompanied by normal spirostanol and furostanol glycosides [4][5][6][7][8][9][10][11][12] ; esculeogenin A is easily converted into a pregnane derivative by refluxing with aqueous pyridine, 13) and pregnane glycoside has been obtained from the over-ripe tomato fruit. 14) These facts strongly suggest that orally administered steroidal glycosides can be metabolized into pregnane derivatives, which are a type of steroidal hormone.Therefore, in further experiments, men consumed tomatoes and their urine was collected and separated with various column chromatographies to afford 3 androstane derivatives. 15)These androsterone analogs are normally excreted; however, because no excretions were detected in the control samples, the occurrence of androsterone analogs indicated excretion via the production of progesterone by subjects that had consumed tomatoes. The tomato steroidal glycoside might stimulate the hormone secretor or perhaps is itself metabolized into the pregnane. We hypothesize that orally administered steroidal glycosides such as spirostanol, furostanol and spirosolane glycosides are metabolized, introducing a hydroxyl group at C-23. These intermediates may then be metabolized into pregnane derivatives.Thus, we conclude that the tomato saponin esculeoside A