Alpha-oxidation of amine derivatives by azodicarboxylate was examined. Among several azodicarboxylate esters and amides tested, bis(2,2,2-trichloroethyl) azodicarboxylate, that has highly electrophilic 2,2,2-trichloroethoxycarbonyl functional groups, was found to have excellent oxidation reactivity. Acylated or carbamoylated amines were suitable substrates for this reaction condition. Tertially amines could react in the same manner, but spontaneous elimination of hydrazinyl group occurred to give dimerized products. The reaction products were found to react with nucleophiles in the presence of Lewis or Bronsted acid catalyst. This strongly suggests that the reaction products, alpha-hydrazinated amine derivatives, might serve as carbonyl group equivalents, very useful intermediates in synthetic organic chemistry.

Current tumor therapies, including immunotherapies, focus on passive eradication or at least reduction of the tumor mass. However, cancer patients quite often suffer from tumor relapse or metastasis after such treatments. To overcome these problems, we have developed a natural killer T (NKT) cell-targeted immunotherapy focusing on active engagement of the patient's immune system, but not directly targeting the tumor cells themselves. NKT cells express an invariant antigen receptor α chain encoded by Trav11 (Vα14)-Traj18 (Jα18) gene segments in mice and TRAV10 (Vα24)-TRAJ18 (Jα18) in humans and recognize glycolipid ligand in conjunction with a monomorphic CD1d molecule. The NKT cells play a pivotal role in the orchestration of antitumor immune responses by mediating adjuvant effects that activate various antitumor effector cells of both innate and adaptive immune systems and also aid in establishing a long-term memory response. Here, we established NKT cell-targeted therapy using a newly discovered NKT cell glycolipid ligand, RK, which has a stronger capacity to stimulate both human and mouse NKT cells compared to previous NKT cell ligand. Moreover, RK mediates strong adjuvant effects in activating various effector cell types and establishes long-term memory responses, resulting in the continuous attack on the tumor that confers long-lasting and potent antitumor effects. Since the NKT cell ligand presented by the monomorphic CD1d can be used for all humans irrespective of HLA types, and also because NKT cell-targeted therapy does not directly target tumor cells, this therapy can potentially be applied to all cancer patients and any tumor types.

Piceatannol (3,3′,4,5′-tetrahydroxy- trans-stilbene, 2), an oxygenated analog of resveratrol (1), was synthesized. It is one of the naturally occurring polyphenolic stilbenoids contained in red wine, and possesses many kinds of beneficial effects such as anticancer activity. The trans-stilbene skeleton of 2 was constructed by Pd-catalyzed Suzuki-Miyaura cross coupling reaction of triflate 8 with ( E)-alkenylboronoate 13. The key intermediate 13 was prepared diastereoselectively by acid-catalyzed hydroboration of pinacolborane 12 to alkyne 11.

To the human nose, mice produce unique, persistent and potent odour which is widely assumed to be derived mainly from their urine. In this review, we discuss why the mouse odour is so potent and long-lasting to the human nose. Sensory and chemical analyses have revealed that 2-sec-butyl-4,5-dihydrothiazole (SBT) was the major mousy odorant and present almost exclusively in male urine. It is not depleted from urine even after repeated headspace or solvent extractions since its majority is tightly bound to the major urinary proteins (MUPs) in male mouse urine that serve to control the release. The urinary concentration of SBT is estimated to be around several hundred parts per million when the binding of SBT to MUPs is considered, while its human olfactory threshold is estimated to be approximately at the parts per billion level. Therefore, the strikingly persistent quality of mouse urine odour, mainly contributed by SBT, is explained by its low human olfactory threshold, its presence in urine at a high concentration, and its delayed release by MUPs. Copyright © 2016 John Wiley & Sons, Ltd.

Reproductive physiology in female mouse is profoundly affected by male odor. A well-known effect of male odor is the acceleration of puberty onset in prepubertal female mice exposed to male urine. Whether peripubertal exposure to male odor also influences female sexual behavior in adulthood is poorly known. Recently, we reported that female mice exposed to male-soiled bedding showed advanced vaginal opening associated with early expression of male-directed odor preference in adulthood. The aim of the present study is to determine whether peripubertal exposure to male urinary chemosignals affects both occurrence of vaginal opening and attraction to male odor at older age in female mice. Therefore, we exposed female mice to (1R, 5S, 7R)-3,4-dehydro-exo-brevicomin (DHB), 6-hydroxy-6-methyl-3-heptanone (HMH) and (S)-2-sec-butyl-4,5-dihydrothiazole (SBT), individually or in mixture, from postnatal day (PD) 21 to PD38 and monitored the occurrence of vaginal opening. We measured then the time that the female mice spent sniffing male and female mouse urinary volatiles at PD45. As expected, peripubertal exposure to DHB, HMH or SBT accelerated vaginal opening in female mice. In addition, we showed that exposure to a mixture of these three compounds induced expression of male-directed odor preference at PD45, contrary to the single exposure to each of these molecules. In conclusion, the volatile compounds DHB, HMH and SBT in urine of male mice influence both occurrence of vaginal opening and adult expression of male-directed odor preference in female mice.

Noncytotoxic anticancer α-galactosphingolipid agelasphin-9b (1) was isolated in 1993 from an Okinawan marine sponge. Since then, a large number of natural and synthetic glycolipids were bioassayed as immunostimulants, which activate natural killer T cells to generate cytokines such as interferon γ (IFN-γ) and interleukin 4 (IL-4). Some of them (2–6) are known to be drug candidates for autoimmune disease or cancer.Download : Download full-size image Our chapter will review the methods used for the synthesis of these compounds, and also the structure–activity relationships among them. Recent biological and X-ray crystallographic studies show that each of the glycolipids is a ligand to make a complex with CD1d protein, and the complex can be recognized by T-cell receptor to induce the generation of cytokines such as IFN-γ and IL-4. Accordingly, it is important to identify the naturally occurring ligand(s) in animal bodies. In 2011, 7 (β-GluCer) was proposed as the natural and endogenous ligand. Synthesis and bioassay of 7 and its relatives will also be reviewed.Download : Download full-size image Finally, future clinical application of these noncytotoxic immunostimulants will be discussed. (for a previous review please, see K. Mori, T. Tashiro, Heterocycles, 2011, 83, 951–1003.)

近年,T細胞の一種であるナチュラルキラーT(NKT)細胞の機能が次々と明らかにされている.このリンパ球は糖脂質抗原を認識して活性化され,多種類のサイトカイン産生を行って免疫賦活・抑制両方の反応を誘導することができる.目的とする免疫応答を選択的に誘導させるために,種々の糖脂質抗原を用いた構造活性相関研究が精力的に行われている.また,2012年にはNKT細胞療法による肺がん治療が先進医療Bとして承認された.NKT細胞とはどのようなものなのか,その活性化機構とともに概説する.

RCAI-80 is one of the ester analogs of KRN7000 (α-galactosylceramide). This compound released mainly T helper 2 (Th2) cytokines, such as IL-4 rather than T helper 1 (Th1) cytokines, such as IFNγ from the invariant natural killer T (iNKT) cells. In addition, it has been known that some of the hydroxylated derivatives of KRN7000 make the cytokine secretion bias to Th2 by decreasing the IFNγ production to almost zero. This time, the three compounds having these two characteristic properties, namely an ester group and also some extra hydroxy groups existing on the ester side chain and/or on the 2-acyloxy-3,4-dihydroxyoctadecyl main chain of RCAI-80, were synthesized to examine the biological activities. As a result, it was found that these compounds made the cytokine secretion skew to Th2. Therefore, their effectiveness for experimental autoimmune encephalomyelitis (EAE) was examined. It was recognized that one of them showed moderate suppression of EAE symptom.

We synthesized ten new analogs of 6′-modified KRN7000 (A): RCAI-58, 61, 64, 83, 85–87, 113, 119, and 125. They could be synthesized by α-selective galactosylation of ceramide 9 with the 6-modified d-galactopyranosyl fluorides (8a–8f) or l-arabinopyranosyl fluoride (17), or by etherification of the known alcohol 19. Bioassay of the ten analogs demonstrated that RCAI-61 (1, 6′-O-methylated analog of A) was the most potent immunostimulant among them, and could induce the production of a large amount of IFN-γ even at a low concentration in mice in vivo.

KRN7000 is one of the alpha-galactosylceramides, which has a 2-hexacosanoylamino-3,4-dihydroxyoctadecyl group. This compound, known as a ligand for the activation of CD1d mediated invariant natural killer T cells (iNKT cells) which release both T helper 1 (Th1) cytokines such as IFN gamma and Th2 cytokines such as IL-4, has been anticipated as an antitumor drug, because of its strong secretion of IFN gamma. This time, we focused on the hydroxylated analogues of KRN7000 which could be thought of as increasing hydrophilicity and showing bias to Th2 cytokine (IL-4) secretion. Therefore, they may become the drugs for autoimmune diseases for the following reasons: (i) compound OCH, one of the alpha-galactosylceramide analogues with a shorter sphingosine chain than KRN7000, increases hydrophilicity relative to KRN7000; and (ii) OCH is known to induce much more Th2 cytokines (IL-4) than Th1 cytokines from iNKT cells compared to KRN7000. Naturally, OCH has become one of the candidate drugs for autoimmune diseases. The more hydroxylated derivatives of KRN7000 are anticipated to induce Th2 bias. Therefore, eight analogues with 1-4 excess hydroxyl groups on the lipid chain of KRN7000 were synthesized to examine if they behave in the same way as OCH. As a result, three out of eight compounds biased largely to IL-4 secretion, and their effectiveness for experimental autoimmune encephalomyelitis (EAE) was examined. It was recognized that two compounds (dagger)RCAI-147/-160 showed good suppression of EAE symptoms. (C) 2013 Elsevier Ltd. All rights reserved.

We synthesized seven new analogues of KRN7000: RCAI-133 and 154-159. RCAI-154, 156 and 158 are secondary-amide analogues having a hydroxy, a methyl or two methyl groups at the alpha-position of a linear C-18-acyl chain, respectively. RCAI-155, 157 and 159 are corresponding N-methylated tertiary amide analogues, and RCAI-133 is the N-methylated KRN7000. Among them, a PBS solution of RCAI-133 induced mouse lymphocytes to produce Th2-biasing cytokines in vivo, while RCAI-154-159 showed only weak or almost no immunostimulatory activity. Therefore, N-methylation led the glycolipid to produce predominantly Th2-type cytokines, while acyl alpha-substitution was detrimental to activity.

RCAI-147 is one of the hydroxylated analogues of KRN7000 which is known as a ligand for the activation of CD1d mediated invariant natural killer T cells (iNKT cells) and releases both T helper 1 (Th1) cytokines such as IFN-γ and T helper 2 (Th2) cytokines such as IL-4. KRN7000 has been anticipated as an antitumor drug or an adjuvant for viral infection such as influenza, because of its strong secretion of IFN-γ. In an interesting twist, it has been obvious in our previous paper that RCAI-147 induces much more Th2 cytokines (IL-4) than Th1 cytokines (IFN-γ) from iNKT cells compared to KRN7000, and shows fairly good result in the experimental autoimmune encephalomyelitis (EAE) test. Therefore, synthesis of RCAI-172 (C6-OH epimer of RCAI-147) was attempted to examine the biological activity. As a result, RCAI-172 was synthesized and its biological activity biased to Th2 response largely compared to that of KRN7000. However, this level decreased to approximately 61% compared to that of RCAI-147. And the clinical score of RCAI-172 for EAE suppression was disappointing. There exist seven chiral centers in the aglycon part of RCAI-172, and even though the change of configuration is just one position (C6-OH), the effect on both Th1/Th2 response and EAE test is fairly large.